Intimate partner physical violence increases women’s risk for negative health outcomes and is an important public health concern. The purpose of the present study was to determine 1) the proportion of girls (≤18 years) and women (>18 years) who experienced physical violence by a sexual partner, and 2) factors (including self–reported HIV infection) associated with girls and women who experienced physical violence by a sexual partner.Cross–sectional surveys conducted in the Gem Health and Demographic Surveillance System (HDSS) area in Siaya County, western Kenya in 2011–2012 (Round 1) and 2013–2014 (Round 2).Among 8003 unique participants (582 girls and 7421 women), 11.6% reported physical violence by a sexual partner in the last 12 months . Three factors were associated with physical violence by a sexual partner among girls: being married or cohabiting (nearly 5–fold higher risk), low education, and reporting forced sex in the last 12 months (both with an approximate 2–fold higher risk). Predictive factors were similar for women, with the addition of partner alcohol/drug use and deliberately terminating a pregnancy. Self–reported HIV status was not associated with recent physical violence by a sexual partner among girls or women.Gender–based physical violence is prevalent in this rural setting and has a strong relationship with marital status, low education level, and forced sex among girls and women. Concerted efforts to prevent child marriage and retain girls in school as well as implementation of school and community–based anti–violence programs may help mitigate this risk. Intimate partner violence (IPV), where an individual  causes physical, sexual, or emotional abuse to their partner, occurs worldwide and has serious physical health and psychological consequences . MoreoveAdolescent girls are at a greater risk of HIV infection compared to their male age–mates in lower and middle income countries . Our aimTwo cross–sectional surveys evaluating HIV risk behaviors, HIV sero–status factors, HIV prevention services and care and treatment uptake were conducted within the Kenya Medical Research Institute (KEMRI) Health and Demographic Surveillance System (HDSS) area in Gem, located in Siaya County in rural western Kenya. The KEMRI HDSS offered a sampling frame of all the registered housing compounds (14 501 in 2010). A compound is a cluster of houses usually occupied by households of the same extended family and usually demarcated by a fence. A random sample of 4000 compounds was selected through a community–based simple random approach. This entailed all compounds in the village being given a unique registration number, thus there was no possibility of sampling bias.Compounds were randomly chosen by a combination of methods: community participation which included community leaders (n = 25) picking pieces of paper from a bucket and the study statistician picking random numbers via a computer until a total sampling frame of approximately 6000 compounds was identified. Trained field staff visited each compound; all households within the compound were approached and all individuals aged 13 years and above who had slept there the prior night and gave informed consent were interviewed. All eligible persons were verbally informed of the study, and if in agreement then provided written consent (see Ethics section). The two surveys took place March 2011 to September 2012, and January 2013 to April 2014, respectively. The survey targeted 15 000 individuals. Persons who were not residents of the HDSS, but who slept in the sampled compound the night prior to the survey date, were also enrolled and interviewed as long as they met the inclusion criteria and provided informed consent. The intention was to interview the same persons in the sampled housing compounds during Round 1 and Round 2 in order to develop a community–based platform to evaluate various infectious and non–infectious disease interventions. However due to in–migrations and out migrations experienced in the HDSS, not all respondents in Round 1 were interviewed in Round 2 and vice versa, as well as people simply not found at home.HDSS was launched in September 2001 by the US Centers for Disease Control and Prevention in collaboration with KEMRI, and provides general demographic and health information, as well as disease and intervention information, in western Kenya. Gem HDSS is located about 20 km northeast of Lake Victoria in Siaya County, formerly Siaya District. Residents are predominately of Luo ethnicity, and their major economic activity is subsistence farming . The midUsing the Gem HDSS as a sampling frame, a questionnaire focusing on HIV risk behaviors and health service uptake was administered immediately before HIV testing and counseling to avoid knowledge of the HIV test result which could have influenced responses. The questionnaire targeted all persons in the household  meeting specific age criteria. Inclusion criteria were age ≥13 years, resident of Gem, and willing to give informed consent to participate in the survey. The questionnaire was structured and pre–coded and administered using a computer–assisted personal interview (CAPI). This was similar to a paper questionnaire because trained interviewers asked participants the questions and recorded their responses. Thus, even the few who were functionally illiterate could participate in the survey. The questionnaire was available in three languages, English, Kiswahili and Dholuo. Trained field staff used the HDSS household list to randomly select eligible household members for an interview. All interviews were conducted in the home privately. Interviewers were trained on the general interviewing techniques as well as on how to use Questionnaire Design Studio (QDS) for CAPI.The dependent variable was female responses to the question, “Have any of your sexual partners in the last year hit/slapped/kicked or done anything else to hurt you physically in the last 12 months?”  (yes/no). It should be noted that emotional abuse was not captured in this question. Independent variables were chosen from the survey based on the existing literature and included age, highest level of education, source of income, marital status , number of pregnancies, ever deliberately terminated a pregnancy, lifetime number of sex partners, ever used a condom (yes/no), age at first sex, most recent self–reported HIV test result, would say yes/no to sex if they knew their partner had an STI, forced sex in last 12 months (yes/no) , and partner used alcohol before last sex and/or drug use in last 12 months (yes/no). For the last 3 independent variables, if the response was “yes” for any of the sexual partners the respondent had in the last 12 months, the variable was coded as a “yes”. Because a large number of participants had missing HIV laboratory test results, we used self–reported HIV status. To ensure that self–reported HIV status was a valid measure, we examined a subset of persons in Round 1 who had both laboratory verified HIV test result and self–reported test results for degree of agreement. The kappa statistic was 0.87, which indicated that self–reported HIV status could be used as a substitute for the laboratory reported HIV result.All persons received information about the objectives of the study and were informed that the information they provided would be kept private, that they could choose not to participate, and that they would not be identified when the information was reported. Girls 13–17 years of age provided consent if they were independent mature minors . For non–mature minors, parental consent and child assent was required. Thus, informed consent or assent was obtained from all individual participants included in the study. Survey participants were given a bar of soap as a token of appreciation for their participation. All procedures performed were in accordance with the ethical standards of the institutional and national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards. The study protocol, consent forms, and data collection instruments were reviewed and approved by the Centers for Disease Control and Prevention and the KEMRI local and national Ethical Review Committees (SSC1801).P–values ≤0.2 in the bivariate model were entered into the multivariable model selection. In developing a final multivariable model, backward selection was applied with a P–value less than 0.05 as the selection criterion. A robust Poisson model with sandwich standard error estimator  was used to estimate the risk ratios (RR) in the bivariate models and adjusted risk ratios (aRR) in the multivariable models [We conducted descriptive analyses as well as bivariate and multiple regression analyses to determine factors associated with girls (≤18 years old) and women (>18 years old) who experienced physical violence by a sexual partner. Due to sparse numbers, we had to combine the responses to two questions regarding partner use of alcohol and partner use of drugs even though the time frames were different. We collapsed the data for number of pregnancies because there were not enough females with zero pregnancies to be able to code nulliparous as a separate category. In the first step of model selection, a bivariate model was applied which included only a single variable at a time to be associated with experiencing physical violence by a sexual partner. All candidate variables that had e models ,13.The intent was to re–interview the same persons in Round 1 and Round 2 and to interview persons in the sampled compounds in Round 2 who were not found during Round 1. However, due to immigration and emigration, some persons who participated in the Round 1 survey were not available to participate in the Round 2 survey and persons were interviewed in Round 2 who did not participate in Round 1. Thus, we used GEE to control for the correlation between the two rounds of data. For the females who participated in Round 1 and Round 2, if the female reported having experienced physical violence by a sexual partner in Round 1, in Round 2 or in both, they were considered as having experienced physical violence by a sexual partner.There were a total of 28 383 participants surveyed during the two study rounds, of whom 11 312 were male and thus removed from the analysis. Among the females, 3821 were removed because they did not answer the violence question. Finally, as we were interested in examining experience of physical violence by a sexual partner, we removed 3780 females who did not report ever having had sexual intercourse or who had not had sexual intercourse in the past 12 months. After accounting for duplicates (the same person interviewed in Rounds 1 and 2), the final number of unique participants was 8003  = 23, 42). The median age was 17 years old for girls in Round 1 with IQR  and the same for Round 2. The median age was 32 years for women in Round 1 with IQR  and also 32 years in Round 2 with IQR . Nearly half of girls ≤18 years of age and more than 85% of women >18 years of age were married (P = 0.01). Of the 3831 females who participated only in Round 1, 8.6% of girls and 14.7% of women experienced physical violence from a sexual partner. Of the 2705 females who participated only in Round 2, 7.4% of girls and 10.0% of women experienced physical violence from a sexual partner. Lastly, of the 1467 females who participated in both data collection rounds, 25.0% (2 of 8) of girls and 8.2% (120 of 1459) of women experienced physical violence by a sexual partner.Among the 8003 unique participants, a significantly higher proportion of women reported physical violence by a sexual partner than girls  = 1.17, 3.56) compared to girls who had completed primary school or had higher levels of education. The risk was nearly 5 times as high for girls who were married or cohabiting  compared to being single, divorced widowed or separated, and nearly 5 times as high for girls who had 3 or more lifetime sexual partners  compared to 1. In addition, the risk of experiencing physical violence by a sexual partner was approximately twice as high for girls who reported their partners never used a condom , and would not say no to sex if partner had an STI . Finally, the risk was more than twice as high among girls who reported forced sex in last 12 months  and that their partner used alcohol at last sex and/or drugs in last 12 months . The number of girls who experienced physical violence by a sexual partner and self–reported being HIV positive (n = 3) were too few for analysis  compared to girls who had completed primary school or had higher levels of education, nearly 5 times as high among girls who were married or cohabiting  compared to being single, divorced widowed or separated, and more than twice as high among girls who reported forced sex   compared to women who had completed primary school or had higher levels of education. The risk was nearly 50% higher for women who had income from a job or business  or partner/family  than no source of income, nearly twice as high for women who were married or cohabiting  compared to being single, divorced widowed or separated, and 29% higher for women who had 0–2  and 51% higher for women who had 3–4 pregnancies  compared to those having 5 or more. In addition, the risk was twice as high for women who deliberately terminated a pregnancy , 60% higher for women who had 3 or more lifetime sexual partners  compared to 1, and over three times as high for women who reported forced sex in last 12 months . Finally, the risk of experiencing physical violence by a sexual partner was more than twice as high among women who reported that their partner used alcohol at last sex and/or drugs in the last 12 months , 27% higher among women who reported age at first sex was >15 years  and 13% lower among women who reported their partners had not ever used a condom . The risk of experiencing sexual violence by a partner was 54% higher among women in Round 1  than in Round 2. There was no significant association between women who experienced physical violence by a sexual partner and self–report of HIV status   compared to women who had completed primary school or had higher levels of education and twice as high for women who were married or cohabiting  compared to being single, divorced widowed or separated. In addition, the risk was 34% higher among women who had ≥3 lifetime sexual partners  compared to 1 and more than 2 times as high among women who reported forced sex in last 12 months . The risk was 62% higher among women who had 0–2 pregnancies  and 55% higher among women who had 3–4 pregnancies  compared to those having 5 or more. Finally, the risk was nearly twice as high among women who reported that their partner used alcohol at last sex and/or drugs in the last 12 months  and 45% higher among women who reported deliberately terminating a pregnancy . The risk of experiencing physical violence by a sexual partner was 21% higher among women in Round 1  than in Round 2  than for women (11.8%). This is on the lower end of the range of reports of any physical violence  in the last year of between 3% and 52% of women in a global review  and loweGirls and women had three factors associated with experiencing physical violence by a sexual partner in common: low education, being married or cohabiting, and experiencing forced sex in the last 12 months. The risk of experiencing physical violence by a sexual partner was nearly twice as high for girls who had no education or only some primary school education compared to girls who had completed primary school or higher. For women the risk was lower, though nonetheless significant with women who had less education having a 15% greater risk of experiencing physical violence by a sexual partner than women with primary school education and above. Low education level has repeatedly been shown to be a risk factor for a host of adverse life events experienced by girls and women ranging from early sexual initiation , sexuallOther factors associated with women who experienced physical violence by a sexual partner included alcohol and/or drug use by their partners and ever deliberately terminating a pregnancy. Data from the Kenya Demographic Health Survey identified Nyanza Province to have the highest rate of IPV with alcohol the strongest risk factor, specifically, a 2.5–higher rate of IPV if husbands are often drunk compared with non–drinking husbands .Our study had several limitations. First, we only included questions on physical violence; we did not include questions on emotional or verbal abuse. Other studies have suggested an overlap between physical violence and psychological and sexual violence ,29. SecoIn conclusion, low education level, being married or cohabiting, and reporting forced sex in the last 12 months were common factors associated with physical violence by a sexual partner for both girls and women in rural Kenya. Addressing violence against women is an urgent public health need . To chan


We investigate the relationship between the various parameters in the Monaco MLC model and dose calculation accuracy for an Elekta Agility MLC. The vendor‐provided MLC modeling procedure — completed first with external vendor participation and then exclusively in‐house — was used in combination with our own procedures to investigate several sets of MLC modeling parameters to determine their effect on dose distributions and point‐dose measurements. Simple plans provided in the vendor procedure were used to elucidate specific mechanical characteristics of the MLC, while ten complex treatment plans — five IMRT and five VMAT — created using TG‐119‐based structure sets were used to test clinical dosimetric effects of particular parameter choices. EDR2 film was used for the vendor fields to give high spatial resolution, while a combination of MapCHECK and ion chambers were used for the in‐house TG‐119‐based procedures. The vendor‐determined parameter set provided a reasonable starting point for the MLC model and largely delivered acceptable gamma pass rates for clinical plans — including a passing external evaluation using the IROC H&N phantom. However, the vendor model did not provide point‐dose accuracy consistent with that seen in other treatment systems at our center. Through further internal testing it was found that there existed many sets of MLC parameters, often at opposite ends of their allowable ranges, that provided similar dosimetric characteristics and good agreement with planar and point‐dose measurements. In particular, the leaf offset and tip leakage parameters compensated for one another if adjusted in opposite directions, which provided a level curve of acceptable parameter sets across all plans. Interestingly, gamma pass rates of the plans were less dependent upon parameter choices than point‐dose measurements, suggesting that MLC modeling using only gamma evaluation may be generally an insufficient approach. It was also found that exploring all parameters of the very robust MLC model to find the best match to the vendor‐provided QA fields can reduce the pass rates of the TG‐119‐based clinical distributions as compared to simpler models. A wide variety of parameter sets produced MLC models capable of meeting RPC passing criteria for their H&N IMRT phantom. The most accurate models were achievable using a combination of vendor‐provided and in‐house procedures. The potential existed for an over‐modeling of the Agility MLC in an effort to obtain the fine structure of certain quality assurance fields, which led to a reduction in agreement between calculation and measurement of more typical clinical dose distributions.PACS number(s): 87.56.nk, 87.53.Kn, 87.55.km, 87.55.Qr The Agility multileaf collimator (MLC)  contains 160 leaves that can be interdigitated to deliver complex IMRT and VMAT plans.The procedures associated with the vendor‐supplied quality assurance (QA) package generally suggest abiding the defaults for all but a single parameter labeled “leaf offset.” This parameter is meant to define the physical deviation from the calibrated “zero position” of the MLC leaves that might occur during the head installation process. Setting a negative value for this number effectively tells the planning system that a set gap between two opposing leaves is slightly smaller physically than the stated gap, whereas setting a positive value indicates to the planning system that the same gap is, in reality, slightly larger physically that what is being set in the planning system. As a result, this leaf offset parameter controls the effective output factor for very small apertures associated with dynamic IMRT and VMAT plans, and can considerably affect the absolute calculated dose.Although the leaf offset is the primary parameter discussed in the vendor‐supplied procedures, the model itself contains many more user‐adjustable parameters.Our in‐house methodology for tuning the MLC model of other treatment planning systems includes a test of both point‐dose and planar dose accuracy, using plans created for the varied anatomical sites provided by the AAPM TG‐119 report.The MLC modeling began with the use of a vendor‐assisted modeling procedure. The QA fields provided by the vendor in the ExpressQA package are delivered by the user to a measurement device of the user's choice, and the results are shared with the vendor. The vendor then uses the results to create an MLC model which is sent back to the user for inclusion in the planning system. After this procedure was completed and our model was in hand, in‐house testing commenced through the use of the ExpressQA package and our own methodologies involving TG‐119‐based planning and delivery. A series of MLC modeling parameter sets were generated, broken into complexity classes. A subset of MLC models considered clinically viable was sent — along with the model provided by the vendor procedure — for external evaluation using the Imaging and Radiation Oncology Core (IROC) H&N phantom.The ExpressQA package consists of eight QA fields. Of these eight fields, two represent simulated H&N ports to provide some means of testing pseudoclinical performance, and two are simple open fields to check symmetry. Four fields remain for discerning specific dosimetric features of the MLC: 3ABUT — a simple step‐and‐shoot plan where three consecutive segments are matched to create a uniform field; DMLC1 — a dynamic sweep field designed to produce the same distribution as the 3ABUT given perfect MLC calibration; 7SEGA — a matching field similar to the 3ABUT with narrower segments; and finally FOURL — a four‐segment, step‐and‐shoot port that consists of progressively smaller nested L‐shapes designed to test tongue‐and‐groove effects and MLC transmission, among other things.To initiate the vendor‐evaluated package, all eight fields were delivered to a Sun Nuclear ArcCHECK  — one of the QA devices explicitly called out as appropriate in the vendor instructions. The measurements were subsequently sent to the vendor, whereupon comparisons were made between Monaco calculated distributions and those measured with the ArcCHECK. An MLC model was tuned by the vendor, and the parameters were installed in our own planning system.Upon receipt of the vendor‐tuned MLC model, we proceeded to perform our standard test of the planning system through the planning and delivery of a variety of simulated treatments based on those found in the report of TG‐119. It was noted immediately that the predicted point doses of the model were deviating, on average, more than we would expect given our historical results. We therefore began recalculating the ExpressQA package in‐house in an attempt to fine‐tune the MLC parameterization. Our in‐house experience revealed an inherent difficulty in the interpretation of ArcCHECK measurement and calculated dose comparisons for the ExpressQA fields. This difficulty was initially thought to be due principally to spatial resolution issues (further discussion of this appears below). This led to the use of EDR2 film as the in‐house QA device of choice for these fields. Emphasis was placed on the 3ABUT and FOURL fields to determine MLC parameters, with the DMLC1 field used to a lesser extent to help diagnose appropriate values for interleaf leakage.Monaco is a Monte Carlo–based treatment planning system which requires the user to adjust allowable statistical uncertainty and voxel size. For the evaluation of the vendor QA fields, a statistical uncertainty of 1% per plan and a voxel size of 2 mm were chosen. For the most part, tests of smaller voxel sizes and statistical uncertainties show no differences in the discernible structure of the dose distributions. The only exception occurred when modeling what the vendor refers to as corner leakage. For this portion of the modeling, the 3ABUT plan was calculated at a 1 mm grid size with 0.5% statistical uncertainty.In addition to the in‐house usage of the ExpressQA package, pseudoclinical plans were also created for a set of structures and dose constraints adapted from the TG‐119 report. With these plans, direct point doses could be measured in phantom to tune not only distribution metrics but also absolute doses both in and out of target.The downloadable phantom provided with the report from TG‐119 was used as the patient for all plans produced in the study. The structure sets used for planning were combination of those included in TG‐119 and custom structures that are intended to provide more realistic anatomical cases for both IMRT and VMAT commissioning and validation.For the TG‐119 portion of this study we used a dose grid resolution of 3 mm, with a statistical uncertainty set to 1% per plan. Both of these values were chosen due to our intent to use these same planning parameters in clinical use. It is possible to create plans of finer resolution and lower noise, but in our current experience such plans would be difficult to produce in a clinically feasible time frame , and it was deemed inappropriate for this section of the modeling to use planning parameters that would not be employed clinically.In Monaco it is possible to set preoptimization limits on the number and size of segments allowed during plan optimization. For the IMRT plans created in this study the total number of segments allowed for an individual beam was set to 30, with a minimum segment width set to 5 mm. For the VMAT plans the total number of segments allowed in an individual arc was limited to 120, with a minimum segment width of 10 mm.The dose calculation algorithm in Monaco reports dose‐to‐medium by default, with the option to convert the reported value to dose‐to‐water. It has been noted that this conversion may introduce uncertainty into the reported dose,Once acceptable plans were created, they were recalculated on a simulated QA water phantom to allow evaluations of planar dose distributions using Sun Nuclear MapCHECK.All fields — both IMRT and VMAT — were set to gantry 0° and recalculated to a depth of 5 cm in the phantom. A discussion of this choice of distribution evaluation follows below.The plans were exported to the record‐and‐verify system and delivered using a Versa HD (Elekta Oncology Systems) linear accelerator fitted with an Agility treatment head.In addition to point doses measured in the solid water stack, plans were also delivered to the Sun Nuclear MapCHECK QA device. IMRT plans were delivered and measured per‐beam, whereas the VMAT plans were measured over a complete arc. All plans, both IMRT and VMAT, were delivered at gantry 0° to remove mechanical gantry sag effects and specifically highlight MLC model deviations.The vendor‐provided QA fields were evaluated using EDR2 film scanned using a VIDAR scanner . The images were imported into RIT113 software  and calibrated using a standard step‐wedge calibration procedure. Using a small MATLAB script , the dose planes from Monaco were converted into RIT MATLAB files for import and comparison. The 3ABUT field was used to investigate changes to the leaf offset, leaf tip leakage, leaf transmission, and corner leakage parameters. The FOURL field was used to investigate changes to the leaf transmission and groove width parameters. And finally, the DMLC1 field (and slight modifications thereof) was used to investigate changes to the interleaf leakage parameter.For the IMRT and VMAT plans delivered to the solid water stack, point‐dose measurements were compared to mean dose values taken averaged over the volume of the ion chamber in the planning system dose distribution. This alleviated some of the statistical noise in the plan and provided a better representation of the predicted measureable dose. Plans were recalculated for a number of parameter combinations in an attempt to match point‐dose measurements on average throughout all plans.The planar dose comparisons were made by exporting dose plane information from Monaco and using Sun Nuclear's patient software to evaluate any discrepancy seen in the measured distribution. Gamma analysis was performed using 2%/2 mm criteria, where the dose is evaluated with respect to the global maximum, and a minimum threshold of 10% of that global maximum is used for inclusion of a data point within the analysis.Once a broad investigation of the parameters was concluded, a subset of all potentially clinically viable parameter‐sets — including three in‐house parameter‐sets and the parameterset provided by the vendor, for comparison — was used to recalculate a previously optimized H&N IMRT plan for the IROC H&N phantom. A comparison was then made between the point dose and distribution measured by the external accrediting body and the four planned dose matrices. As with the above TG‐119 comparisons, any differences seen can be directly attributable exclusively to the MLC model parameters, as each planned dose distribution used the same optimized MLC segments.The vendor procedure for creating an MLC model simply returns an MLC parameter set that is inserted into the planning system via transfer of an .xml file. The relevant parameters from the vendor set are listed in To demonstrate the impact of the choice of particular leaf offset and leaf tip transmission combinations, profiles taken across the 3ABUT field are plotted for distributions calculated using three different MLC models in In addition to parameters describing the physical and dosimetric qualities of the leaf tips, there also exists a parameter in the model to account for tongue‐and‐groove effects. To investigate the effect changes to the parameter sets have on clinical plans, each of the 10 plans created using the modified TG‐119 suite dose distributions were first calculated for several MLC parameter sets where only the leaf offset and leaf tip leakage parameters were changed. In The overall effect of parameter set choice for these pseudoclinical plans is presented in The vendor‐provided model displayed a surprisingly large average deviation between measured and calculated point doses, particularly so in the high‐dose region. The separation between 0% deviation in‐target and 0% deviation in the low‐dose regions that was seen in >95 for all fields of the IMRT plans measured. While the model fared less well for the VMAT plans, the fact that a significant number of plans had “acceptable” pass rates at 2%/2 mm was surprising, given the point‐dose measurements. It was further somewhat surprising to see that model E — the model that most closely matched the QA fields — did not provide the highest gamma pass rates. It should be noted that at a gamma criteria of 3%/3 mm, the pass rates were practically indistinguishable for all models.The MLC model available in Monaco is robust and capable of providing accurate dose calculations for IMRT and VMAT plans at reasonable clinical Monte Carlo calculation parameters. The vendor‐supplied ExpressQA package can be a valuable tool to assist in model parameter determination, but it appears that tuning based on point‐dose measurements is necessary to ensure the greatest plan accuracy. The vendor‐evaluated ExpressQA procedure produced an MLC model that was noticeably inferior to that found with significant internal testing; however, despite this, the vendor‐provided model passed IROC H&N external evaluation.The discrepancy between the vendor‐provided model and that determined in‐house most likely has a diffuse explanation, partially associated with our choice of QA equipment and partially associated with the natural limitations of dose distribution comparison as a method for tuning a head model.In general, a potential deficiency associated with the vendor‐suggested procedure for MLC modeling is the very small number of clinical fields included in the vendor package. A single dynamic dose distribution is provided, and although the field delivers a complex H&N‐style distribution, it remains a single measurement. Our in‐house testing showed that the least accurate model overall could, for any given field, have the highest pass rate at 2%/2 mm. It is not possible to obtain an accurate statistical sense of the MLC model performance without many fields to build those statistics. In fact, the major criticism of the study presented here is almost certainly the limited number of plans calculated and compared. This number was chosen partially due to the number of structure sets available in the TG‐119 package, and partially due to the extended calculation times of the Monte Carlo algorithm, which provided a somewhat ambiguous definition of what constituted a ‘reasonable’ number of model iterations and planned dose distributions.While the QA fields are undoubtedly helpful, they are, by construction, pathological — in the sense that they display intentionally nonclinical characteristics to isolate specific aspects of the MLC. The Monaco MLC model, though robust, in many ways does not attempt to physically replicate the MLC, and as a result there are some aspects of the model which are less dosimetrically representative of the MLC than others.The MLC model used in Monaco 5.0 uses a stack of 11 probability filters, where each filter contains a 2D representation of the MLC leaves.Begin with the default model and create, using TG‐119 or similar pseudoclinical patient data, several different IMRT plans for sites that will typically be treated clinically.Deliver the plans to a QA device that allows point‐dose measurements in both the target and low‐dose regions.Compare average point doses to determine if the average dose in the target should be lowered (decrease leaf offset/leaf tip leakage to match) or raised (increase leaf offset/leaf tip leakage to match).Deliver 3ABUT from the ExpressQA package to the highest‐resolution QA device available; compare result to calculated distribution using the new leaf offset/leaf tip leakage parameters. Make sure the combination chosen gives a reasonable matching to the 3ABUT delivered. If deeper minima in the profile are required, decrease leaf offset while increasing leaf tip leakage to compensate for absolute dose.Once target point dose is matched with reasonable 3ABUT matching, compare average point doses out of target. If low, adjust leaf transmission up to increase out‐of‐field dose, decrease leaf offset/leaf tip leakage to compensate for in‐target increases. If high, adjust leaf transmission down, increase leaf offset/leaf tip leakage.Once both in‐target and out‐of‐target point doses match and 3ABUT is reasonable, create QA plans by recalculating the standard clinical plans on a water‐equivalent phantom in Monaco (to avoid high density uncertainties) and ensure that gamma pass rates are as expected.The process of creating an MLC model in Monaco can range from taking a few measurements to send to the vendor all the way to calculation and comparison of hundreds of point doses and dose distributions. This study indicates that, with the current model, there may be diminishing returns beyond the adjustment of three parameters: leaf offset, leaf tip leakage, and leaf transmission. As such, a reasonable procedure for the creation of an MLC model in Monaco could be described as follows:The MLC model in Monaco is robust and can be tuned extensively to produce accurate calculated dose distributions. However, the number of tunable parameters potentially allows for an overmodeling of the MLC, and in its current form the model adjustment can be limited to changing the leaf offset, leaf tip leakage, and leaf transmission parameters to obtain a good result. The vendor‐provided ExpressQA package is very useful to check the reasonability of the model at MLC segment match‐lines, but point‐dose measurements and planar QA for several different simulated clinical plans seem necessary to guarantee a clinically accurate model.The authors would like to thank Anthony Doemer from Henry Ford Health System, Detroit, MI, for allowing the use of his H&N SIB and Prostate+LN structure sets in this study.This work is licensed under a Creative Commons Attribution 4.0 International License.


Merkel cell carcinomas (MCCs) are uncommon, highly malignant skin tumors that develop in sun‐exposed areas of the skin. Most of the MCCs are CK 20‐positive and CK 7‐negative such as our case. About 80% of Merkel cell carcinoma is associated with Merkel cell polyomavirus. This is an 83‐year‐old lady who presented to her primary care physician with a small lump on her right cheek. Review of systems was otherwise negative. There was no evidence of pathological lymph nodes in mandibular region or cervical lymph nodes. She was referred to a dermatologist who performed excision. Histopathology showed primary neuroendocrine carcinoma Figs  and 2. TMPR: wrote the case description. PB and JS: contributed to the description on Merkel cell carcinoma and the key clinical message. EBM: provided the description of the pathology images.None declared.


UVR) exerts both beneficial and adverse effects on human skin. Epidemiological studies show a lower incidence of skin cancer in people with pigmented skins compared to fair skins. This is attributed to photoprotection by epidermal melanin, as is the poorer vitamin D status of those with darker skins. We summarize a wide range of photobiological responses across different skin colours including DNA damage and immunosuppression. Some studies show the generally modest photoprotective properties of melanin, but others show little or no effect. DNA photodamage initiates non‐melanoma skin cancer and is reduced by a factor of about 3 in pigmented skin compared with white skin. This suggests that if such a modest reduction in DNA damage can result in the significantly lower skin cancer incidence in black skin, the use of sunscreen protection might be extremely beneficial for susceptible population. Many contradictory results may be explained by protocol differences, including differences in UVR spectra and exposure protocols. We recommend that skin type comparisons be done with solar‐simulated radiation and standard erythema doses or physical doses (J/m2) rather than those based solely on clinical endpoints such as minimal erythema dose (MED).Terrestrial solar ultraviolet radiation ( The skin is the body's protective barrier against environmental hazards including solar ultraviolet radiation (UVR). The waveband of terrestrial UVR is ~295–400 nm, of which the majority is UVA , with UVB (~295–320 nm) typically comprising <5%.Skin colour is a major human phenotypic trait and has attracted considerable research by many disciplines. The main determinants of skin colour are epidermal melanin pigments, with minor contributions from carotenoids and de/oxyhaemoglobin in dermal capillaries , in lysosome‐like organelles called melanosomes, and its subsequent transfer to adjacent keratinocytes Figure . Within 2 UVA. These changes are thought to be the consequence of redistribution, oxidation and polymerization of pre‐existing melanin , persistent pigment darkening (PPD) and delayed tanning (DT) Table  Sklar e. IPD pretrans‐urocanic acid) that directly initiate a wide range of photobiological responses. However, in some cases the chromophore is not the target molecule; for example, energy may be absorbed by chromophores to generate reactive oxygen species (ROS) that damage adjacent molecular and cellular targets. ROS also serves other functions such as in cell signalling. As a rule of thumb, UVB and UVA II cause direct effects in normal skin, whereas UVA I causes indirect effects, via ROS, but there are many exceptions. It should be noted that this rule is largely based on in vitro work.The epidermis is rich in UVR‐absorbing molecules, called chromophores Young, , many of→ T transitions) that can lead to skin cancer. There are two major pathways to repair UVR‐induced DNA damage: nucleotide excision repair (NER) and base excision repair (BER). NER is mainly responsible for the repair of 6‐4(PP) and CPD, whereas BER repairs damage to non‐distorting single base modifications caused by oxidation, for example 8‐oxoGua. Inefficient repair is associated with a skin cancer risk that is orders of magnitude greater than normal in xeroderma pigmentosum (XP) patients who have defective NER , especially MMP‐1  and SCC are keratinocyte‐derived cancers known collectively as non‐melanoma skin cancer (NMSC). The incidence of malignant melanoma (MM) is much lower than that for NMSC, but the former are responsible for the vast majority of skin cancer deaths because they are much more metastatic  allele into red Mc1re/e background mice protected red mice from melanoma  . Vitamin D is essential for bone health and there are many studies that suggest that it is important for a wide range of health outcomes, although most of the evidence for these has been disputed Erythema is the best‐studied response to UVR, especially in fair skin. It is used as an indicator of personal UVR sensitivity by determining the minimal erythema dose (MED), which is the lowest UVR dose necessary for a just perceptible redness (or redness with defined borders) at 24 h post‐exposure  for the SPT VI MED (87%) compared with MFD (36%) ]. Using a range of UVR doses, they found an inverse correlation between oITA and CPD, including such damage in melanocytes. A beneficial effect of melanin is perhaps further evidenced by the supranuclear localization of melanin in basal layer keratinocytes, which suggests a protective role of the melanin nuclear ‘cap’  and reported that dark skin/melanin provided a protection factor of around three for CPD, whereas Freeman et al. (2), based on MED, with different skin types makes it almost impossible to assign a protection factor for melanin. We advocate the use of the standard erythema dose that is independent of emission spectrum and personal sensitivity to UVR . Of course, it is possible that this lack of protection may reflect the lack of melanin in previously unexposed buttock skin.There are studies that refute photoprotection by melanin pigment in vitro and in vivo  were not comparable, and there is some evidence that repair/apoptosis is influenced by exposure dose  found no difference in the rate of DNA repair in different skin colours after acute exposure to similar UVR doses or equivalent MED exposures . TUNEL recognizes double‐strand breaks in DNA, a melanin‐mediated mode of cell death  and BED (P < 0.001). The BED in darker skin was approximately two times higher than that in light skin. The lower BED in fair skin was attributed to its higher accumulation of p53 (not serine specific)/unit dose compared to dark skin, although this could also be attributed to photoprotection by melanin.The SBC is used as an endpoint in photoprotection studies and the basis of the term ‘biologically effective dose’ (BED). This is the minimal UVR dose that induces one SBC per 0.45 mm length of epidermis. One ex vivo SSR study  using an emission spectrum with 40%UVB/60%UVA. In contrast to Del Bino , found in high concentrations in the stratum corneum, are major chromophores for UVR‐induced immunosuppression.Photocarcinogenesis requires at least two major steps: DNA photodamage, which may lead to mutation, and the suppression of acquired cutaneous cellular immunity. The UVR‐induced suppression of the contact hypersensitivity response (CHS) is widely used in mice and humans as a model of the immunological events in skin cancer  in fair skin (SPT I‐III), a significant increase in the number of MMP‐1 and MMP‐9 protein‐positive cells. In SPT VI, using the same physical dose, no MMP staining was present probably due to the suberythemogenic doses. These studies do not allow any definitive conclusions to be drawn.Although the benefits of melanin in photoageing are exemplified by ‘near‐universal’ occurrence of elastosis in albino patients in Africa  which enhances pigmentation , either by constitutive or facultative melanin. There are no conclusive data on the ability of melanin to inhibit photoimmunosuppression. Other unknown factors may be important in the differences in skin cancer incidence between black and white skin populations. However, the data on melanin protection of DNA photodamage, if based solely on the limited optical properties of melanin, have profound implications for the prevention of skin cancer in susceptible white skin populations. This is because they suggest that regular use of a low sun protection factor sunscreen or other photoprotection strategies , preferably from an early age, would be very beneficial.2) or SEDs are used rather than MEDs. Different studies use different UVR spectra, which also make comparisons difficult. Where possible, we recommend the use of SSR that also accounts for any spectral interactions.Most photobiology studies have been done on white skin with relatively few contemporaneous comparisons. Often, such comparisons have been done using the MED as the exposure dose unit. Apart from the difficulties in accurately determining an MED in deeply pigmented skin, this means that a skin type VI is typically exposed to a much higher physical dose than a type I. This makes it impossible to calculate the degree of protection afforded by melanin. Furthermore, the action spectra for erythema and DNA photodamage (CPD) are virtually the same, such that CPD is the likely trigger for erythema. This may mean that the endpoint may be predetermined by the exposure dose, all the more so because the CPD may trigger a range of important photobiological responses. Thus, we recommend that physical dose units (J/m


Interprofessional education (IPE) involves two or more professions engaged in learning with, from and about each other. An initiative was undertaken to explore IPE for radiation therapy (RT) and medical physics (MP) students through a newly developed workshop based around simulated learning. The aims of this study were to explore RT and MP students’ perceptions of working as part of a collaborative team and of their own and the other group's professional roles. Student perceptions of the simulation education tool, the virtual environment for radiotherapy training (VERT) system, were also investigated.RT and MP students were invited to participate in a 4‐hour interprofessional workshop. Pre‐ and post‐workshop surveys were employed to collect demographic data, students’ perceptions of interdisciplinary education ) and workshop evaluation (bespoke questionnaire).n = 8; MP, n = 7). Thirteen pre‐ and post‐questionnaires were returned . For both student groups combined, IEPS scores ranged from 64 to 108 and 71 to 108 in the pre‐ and post‐questionnaires, respectively, with insignificant differences in the mean scores post‐intervention . Satisfaction with VERT as a simulation tool was high for both student groups.Fifteen students attended the workshop (RT, The interprofessional student workshop served to promote interprofessional collaboration for RT and MP students. VERT was reported as an appropriate education tool for this purpose, enabling access to virtual clinical equipment common to both student groups. It is suggested that IPE continues to be offered and investigated in RT and MP students, in order to improve effective interprofessional strategies which may enrich future professional collaboration. Interprofessional teams have been associated with improved health care delivery. This has been attributed to the joint intellectual effort of health professionals working together and exploiting skills and knowledge from each individual within the team.IPE generally involves two or more professions engaged in learning with, from and about each other.for students to develop their own professional rolesto enhance students’ understanding of their own and the other profession's role within the radiation oncology context.to characterise the importance of good communication for team work and patient care within radiation oncology.An initiative was undertaken to explore IPE for RT and MP students, through a newly developed interprofessional student workshop. The workshop had three main objectives:Supported by positive experience using the virtual environment for radiotherapy training (VERT) in Australia and overseas,This article reports on the interprofessional student workshop evaluation. The primary aim of this study was to explore RT and MP students’ perceptions of their own profession and the other group's profession, and to investigate perceptions of RT and MP students working as part of a collaborative team. It was hypothesised that the workshop would improve students’ perceptions of interprofessional collaboration. A secondary aim was to investigate students’ experience with the VERT system. This information will contribute to further IPE initiatives, informing interprofessional developments within radiation oncology.Ethics approval for this study was granted by the Human Research Ethics Committees from The University of Sydney. Consent to participate in the study was given by return of questionnaires and all data collected was anonymous. The primary investigator was not academically associated with either student group.This study consisted of a ‐group, pre‐ and post‐intervention test design, using survey instruments for data collection.interprofessional student workshop’ was offered to RT and MP students who were enrolled at two different universities. RT students were enrolled in the second year of the undergraduate Bachelor of Medical Radiation Sciences (RT) stream programme at Charles Sturt University and MP students were enrolled in the first year of the Master of Medical Physics programme at The University of Sydney. These student groups were identified as being at near equivalent stages of theoretical knowledge and clinical experience in terms of the stage through their respective courses, most appropriate to the workshop's learning objectives. All eligible students  were invited to attend the interprofessional student workshop via email communication and/or direct communication by academic staff. The workshop was offered as an extra‐curricular activity. The invitation included a ‘Participant Information Statement’, outlining the workshop details and objectives. Information clearly stated that participation in the workshop did not oblige participation in the study and there would not be detriment to students who chose not to take part. The study was designed to include all RT and MP students who attended the workshop. There was no sampling or selection relevant to this study.The ‘The workshop was four hours in duration and was intended for students at an early stage of their course. Decisions about organisation of the structure, content and learning methods were guided by general educational theory, IPE literature, learning objectives (previously stated) and ensuring that the workshop was attractive to both groups of students in terms of content and relevance.The workshop took place at The University of Sydney's VERT suite . VERT is a back‐projection simulation system, which displays an interactive RT treatment room, equipment  and virtual RT patient  on a large wall‐sized screen.Demographic dataThis section asked students to indicate their gender , age range  and course enrolment . Students were also asked to indicate if they had any prior experience with the VERT system.Interdisciplinary Education Perception Scale (IEPS)The ‘interdisciplinary education perception scale’ (IEPS) was used to explore students’ perceptions of IPE.Workshop evaluationA questionnaire was designed to explore students’ perception of the workshop and the VERT system. In the pre‐ and post‐questionnaires, students were asked to indicate how they perceived the workshop related to their university course (free‐text response). The post‐questionnaire asked students to indicate their level of agreement of 13 statements relating to the workshop , using a 6‐point Likert scale (1 = strongly disagree to 6 = strongly agree). Higher scores indicate better agreement with posed statements.The study period was from May, 2015 to June, 2015. Surveys were created in SurveyMonkey  and distributed through paper‐based surveys (pre‐survey) or online (post‐survey). This design was chosen because it allowed for cost‐effective, rapid data collection and was feasible for the intended study participants. Surveys were anonymous and participants were asked to provide a linking identification code in order to match pre‐ and post‐responses. The pre‐session survey was completed by participants prior to the workshop. Post‐session data were collected via an online survey which was available immediately after the completion of the workshop. Reminder emails were sent to MP students 1 and 2 weeks following the workshop. Consent to participate in the study was given by survey return. Surveys consisted of four sections:Descriptive statistics  were calculated for demographic results (pre‐ and post‐questionnaire), workshop evaluation  and IEPS subscales . In order to test for statistical significance, each participant was given an overall score on each of the four IEPS subscales for pre‐ and post‐workshop questionnaires and scores were combined for RT and MP student groups. A Wilcoxon signed‐rank test was used to compare pre‐ and post‐ survey means for each of the four IEPS subscales using IBM Statistical Package for the Social Sciences (IBM SPSS) for windows (Version 21). Statistical significance was set at 0.05 for all scales. Free‐text responses were independently reviewed by two of the authors  and classified into themes. Final themes were reached by consensus.Fifteen students  attended the interprofessional student workshop. Participation in the workshop did not oblige participation in the study which involved completion of pre‐ and post‐session questionnaires. Whilst the pre‐ and post‐questionnaire included a coding system to match respondents, student non‐compliance with this section did not allow for this. In addressing missing data in the questionnaires, the reported results identify the number of respondents who completed each section.n = 10), the remaining students had seen the VERT system (n = 2) or were unsure (n = 1). The two students who had seen the VERT system were enrolled in RT.There were 13 completed pre‐session questionnaires returned from six RT and seven MP students (response rate for RT and MP students was 75 and 100% respectively). The same number of post‐session surveys were returned from seven RT and six MP students (response rate for RT and MP students was 87.5 and 85.7% respectively). Demographic data are described in Table Z = −1.305, P = 0.192). There was also no statistically significant change in the four subscales . The mean scores and standard deviation for total scores and subscales are listed in Table A total of 11 out of 13 and 12 out of 13 returned questionnaires had complete IEPS sections, in the pre‐ and post‐questionnaire respectively. For RT and MP groups combined, the total IEPS scores ranged from 64 to 108 in the pre‐questionnaire and 71 to 108 in the post‐questionnaire. A Wilcoxon signed‐rank test on total IEPS scores showed that the ‘interprofessional student workshop’ did not elicit a statistically significant change in students’ perceptions of IPE  responded to the pre‐questionnaire section asking how well they perceived the workshop fitted with their university course. There were two main themes identified within students’ free‐text responses via the frequency of the themes mentioned. A common theme was students’ positive expectations of the potential value of the workshop, although this was expressed mainly from their own student‐practitioner viewpoint. Students gave examples of perceived benefits such as:‘I think it is extremely important to be a part of this workshop. It will be great for a deeper understanding of the practical side of our professions’. ‘It will be useful to build a better understanding of the role of medical physics in radiation therapy’ A total of 11 out of 13 students who completed the pre‐questionnaire A second theme involved students’ view of the perceived benefits of practicing skills in a virtual environment, as one student expressed:n = 5; MP, n = 2) responded to the question asking how well they considered the workshop fitted with their university course. Overall, students responded positively at the completion of the workshop, with a high regard for the VERT system. The first theme included students’ subjective feeling that the workshop supported understanding of their professional roles:‘Training under the VERT workshop achieved a good understanding of the profession’ In the post‐questionnaire, seven out of 13 students who completed the post‐questionnaire ‘The VERT system itself was great, but combining the MP and RT was semi pointless. I thought the RT students were more advanced and had to wait for the MP students to catch up. However, playing with the VERT system was great fun’. The second theme identified included students’ ideals of learning as an interprofessional group:In the post‐questionnaire, a total of seven RT students completed questions about VERT display and use (100% response rate). One RT student did not complete the knowledge and understanding section, hence only six RT students completed this section. Three MP students completed this section of the questionnaire (50% response rate). MP students’ scores had higher means for questions addressing the workshop's effect on knowledge and understanding. The workshop content had good response to relevance in both student groups and was not considered difficult to understand. All the VERT display features identified were highly rated, by both student groups and there was a high regard for using VERT simulation as the central learning tool for the workshop. Statistics are summarised in Table Z = −1.305, P = 0.192). This may suggest the interprofessional student workshop was able to positively influence students’ perceptions of IPE, although this cannot be ascertained and is not supported by statistical significance. These scores are higher than previously reported IEPS scores for undergraduate medical, nursing and surgical technology students.To our knowledge, this study was the first to utilise VERT in an interprofessional workshop setting for RT and MP students. Outcomes of students’ perceptions of IPE indicated positive changes post‐intervention, although our results cannot confirm that these changes were due to the educational intervention. IEPS mean scores increased from 93.6 to 94.3 in the RT student group and from 86.5 to 89.4 in the MP student group. Differences between RT and MP scores can be attributed to students’ own perceptions, as well as students being from different universities and study programmes, as researchers have found these factors influence attitudes to IPE.P > 0.05). The reason for this is uncertain and difficult to justify for this small student sample.For individual student groups, mean scores for three out of the four subscales  increased or remained the same in the pre‐ and post‐questionnaires for both student groups. Mean scores for ‘perceived need for cooperation’ decreased for both groups  and experience (following workshop) of seeing and operating the VERT system, consistent with student experience of VERT in other studies.The sample size for this study was small, therefore, this article relies on trends in survey response rather than statistically based evidence. In addition, some questions had very low response rate which likely compromises the reliability of the results from a statistical analytical viewpoint. Whilst this reduces the ability to generalise results to a greater population, the data collected support the exploratory nature of the study as well as future research into IPE for RT and MP students. Another limitation lies within the reliability of the IEPS scale for RT and MP student groups, although it has been used other health profession students.It was not possible to include the interprofessional student workshop into RT or MP student curriculum. The interprofessional student workshop was therefore offered as an extra‐curricular activity, which can account for the low attendance rate by the MP group . Nonetheless, this resulted in RT and MP students being almost equally represented.In the future, interprofessional simulation workshops could be integrated into university curriculums in order to improve participation rates, and incorporate other radiation oncology professional groups, such as radiation oncology registrars and nurses. It is currently unclear how MP and RT IPE at university level could influence interprofessional collaboration at a student level and, later, at practitioner level. Longitudinal studies could be undertaken, which specifically evaluate impacts on translation into practice.In conclusion, results from the workshop evaluation are encouraging and serve to promote educational activities where RT and MP students can learn with, from and about each other. Students’ interaction with virtual clinical equipment was positive, and VERT as a simulation education tool proved to be an appropriate and enjoyable tool. It is suggested that IPE continues to be evaluated in RT and MP students, in order to ascertain if these experiences can translate to improved professional collaboration, with positive effects to RT patient care.The authors declare that there is no conflict of interest regarding the publication of this paper.Informed consent was obtained from all individual participants included in the study.


The impact of integrated reproductive health and HIV services on HIV testing and counseling (HTC) uptake was assessed among 882 Kenyan family planning clients using a nonrandomized cohort design within six intervention and six “comparison” facilities. The effect of integration on HTC goals (two tests over two years) was assessed using conditional logistic regression to test four “integration” exposures: a training and reorganization intervention; receipt of reproductive health and HIV services at recruitment; a functional measure of facility integration at recruitment; and a woman's cumulative exposure to functionally integrated care across different facilities over time. While recent receipt of HTC increased rapidly at intervention facilities, achievement of HTC goals was higher at comparison facilities. Only high cumulative exposure to integrated care over two years had a significant effect on HTC goals after adjustment , and programs should therefore make efforts to roll out integrated services to ensure repeated contact over time. The integration of reproductive health (RH) and HIV services is hypothesized to have multiple service‐ and health‐related benefits. In addition to increasing cost‐effectiveness, it is expected that the co‐location of services under one roof, or within one consultation room, will minimize problematic referral processes and increase service uptake, and thus impact RH‐ and HIV‐related behaviors and outcomes  is a critical public health goal, since the proportion of adults who know their HIV status rarely exceeds 50 percent in most high‐ and medium‐HIV prevalence settings UNAIDS . Annual Repeated testing every 6 to 12 months has been recommended by the World Health Organization since 2007 for those at higher risk of HIV exposure. In Kenya, where HIV prevalence is estimated at 6.1 percent UNAIDS  and riskMultiple strategies have been designed and evaluated to promote uptake of HTC within generalized epidemics. Provider‐initiated testing and counseling for HIV is one intervention that has shown proven impact on HIV testing uptake when services were integrated within antenatal care, primary care, STI, and TB services  to strengthen the provision of integrated FP‐HIV services. Compared to the national average, at the time of the research the region had a higher modern contraceptive prevalence (46 percent versus 67 percent)  design to measure the effect of integrated health care in intervention sites. Due to challenges in ensuring program implementation in intervention sites, and the existence of non‐Integra integration activities in “control” sites, the latter are referred to as “comparison sites,” and in this article we treat the whole sample as a cohort to assess the effect of individuals’ exposure to integrated care on HIV testing outcomes. The cohort was female FP clients (aged 15–49 years) attending the six intervention and six comparison facilities. The facilities included six hospitals and six health centers. Characteristics of study facilities are described in Table Intervention sites were selected based on good performance in a previous integration study  (immediately after intervention implementation), round 1 (r1) (r0+6 months); round 2 (r2) (r0+18 months); and round 3 (r3) (r0+24 months). The recruitment interview took place at the health facility using a structured questionnaire on a personal digital assistant (PDA), and subsequent interviews were conducted either at the respondent's home or at an arranged meeting at the health facility, also using PDAs. The questionnaire was in Kiswahili and collected data on socio‐demographic characteristics, family planning practices, HIV‐related behaviors and practices, service‐use history, and perceptions of service quality. Respondents gave their informed consent before each interview.At recruitment, clients were sampled consecutively as they exited consultations. Sample size calculations were based on having 80 percent power to detect an absolute between‐group increase from 5 percent to 10 percent in another study outcome (consistent condom use) among those using other contraceptive methods. Based on condom use estimates in a previous study , the following women were excluded sequentially from the analysis: 245 known to be HIV‐positive at recruitment, tested either before or during recruitment consultation (139 in intervention [14 percent] and 106 in comparison [11 percent]); 745 without a complete cohort data history (r0 through r3) (345 in intervention [41 percent] and 400 in comparison [46 percent]); and 86 missing complete data on all potentially confounding variables (64 in intervention [13 percent] and 22 in comparison [5 percent]), resulting in a sample size of 882 for a complete case analysis.At every round, respondents were asked whether they had received an HIV test—during consultation at recruitment, or since their last interview in subsequent rounds—and the date of the test. Participants who remained HIV‐negative (as self‐reported in cohort interviews) and received at least two HIV tests over the two‐year cohort period were considered to have fulfilled the outcome, “HTC goals achieved,” since annual testing is the national recommendation in Kenya NASCOP . Those wWe investigated the impact of service integration on HTC uptake using four different measures of integrated care. The different approaches, summarized in Table The first measure, “Design group,” categorized women by the study arm (per protocol), based on whether the facility from where they were recruited was designated as an intervention or comparison site. This maintains the original quasi‐experimental approach.Subsequent exposures use a cohort study design. The second measure captured each individual woman's actual receipt of integrated services during the recruitment consultation, irrespective of the facility's designation as intervention or comparison site in the study. Services used were self‐reported by women in the exit interview. “Integrated services” were defined as a visit in which a woman received at least one RH service  AND at least one HIV/STI service . Since HIV testing forms a part of this definition, the outcome measure for this exposure was restricted to HIV tests received in rounds 1–3 only (excluding r0).The third measure recorded the degree of integrated care being delivered at the facility at recruitment, as measured by the Integra Functional Integration Index. The Integra Index is a multidimensional score of facility‐level integration derived from data collected through client flow analyses and calculated using latent variable modeling  during the two‐year follow‐up period of the study, and the extent of integration at a facility can vary over time, the fourth measure recorded a cumulative integration score that took into account each woman's individual use of integrated clinics throughout the study (as self‐reported by women in each cohort interview). To calculate the cumulative score, Index scores were summed for every FP visit reported over the two‐year cohort period, although scores for visits to non‐Integra study facilities were not captured . The cumulative exposure score was grouped into three categories—low, medium, and high—based on tertiles of the data .Data were imported into STATA 13.0 for cleaning, checking, and analysis. We used z tests for differences in proportions in HIV testing between cohort rounds, and chi squared tests for crude associations between HIV testing and each of the four measures of integration, as well as between potentially confounding variables and outcome.Potential confounders were identified through a review of the literature of factors influencing HIV testing uptake . Potential effect modification of the relationship between integration and HIV testing by certain variables  gave almost identical results to those that assumed independence, and the latter are reported.Sensitivity analyses were also conducted for missing data on complete cases. We conducted χ2 statistical tests to assess how those with complete cohort data differed from those with an incomplete cohort history across baseline exposure and potential confounding factors. Those with complete data differed from those who were excluded from the analysis in age , and whether they paid fees for services . There was no evidence of a difference in other baseline characteristics or between clinics. The implications of these differences are addressed in the discussion.Table Overall, 69.3 percent of women achieved HIV testing goals over the two‐year cohort. Thirty percent received two HIV tests, 28 percent received three, and 10 percent received four (data not shown). Reports of HIV testing increased markedly over the course of the cohort, from 28 percent at baseline (during consultation) to 48 percent at r1, 65 percent at r2, and 66 percent at r3  (data not shown). In the comparison facilities, an average of 48 percent of participants received an HIV test at baseline , we further tested these associations through multivariable analyses. Association between individual receipt of integration and achievement of HTC goals became nonsignificant after adjustment  (data not shown). For the cumulative clinic integration score exposure, both crude and adjusted associations between integration and HTC goals, as well as with other socio‐demographic and service‐related covariates, are presented in Table how “integration” is measured. Findings also point to the need to articulate a precise definition of the type of integrated service‐delivery that is occurring at any given clinic if meaningful interpretation is to be achieved.This analysis demonstrates the complexity of assessing the effect of health service re‐organization on health and behavioral outcomes. The results show that determining whether “service integration” impacts uptake of HIV testing depends on An integration intervention had a positive effect on initially increasing HIV testing uptake from very low levels immediately post‐intervention, as the proportion of FP clients at these facilities who received an HIV test increased dramatically over the course of the study, particularly in the first six months after the intervention. In contrast, the “comparison” sites provided much higher levels of HIV testing at r0, and levels rose moderately over time. The dramatic increase in HIV testing in intervention facilities replicates positive results reported in a previous uncontrolled study of a similar intervention in Central Province, Kenya , there was still the possibility that tests reported in later rounds were duplications of tests reported earlier. Additionally, reporting bias may have increased over time with repeated survey rounds, thus potentially contributing to the markedly higher rates of testing over the course of the cohort. Reporting bias should not have differed between exposures, however.Assessing the impact of organizational changes on service outcomes is complex and sensitive to measurement definition choices. Using a range of measurements, our findings show that integrated delivery affects HIV testing goals if repeated contact with the integrated‐care delivery is sustained over time. Strategies to integrate HIV testing into FP services must therefore address sustained integrated delivery and encouragement of repeat service use by clients to ensure that they achieve their routine testing goals.


The robotic system has gained wide acceptance in specialties such as urological and gynecological surgery. It has also been applied in the field of upper gastrointestinal surgery. Since the first implementation of the robotic system for the treatment of gastric adenocarcinoma, the procedure has been found to be safe and feasible. Although robotic gastrectomy does not meet our expectations and yield better results than laparoscopic gastrectomy, this procedure seems to provide several advantages over laparoscopy such as reduced blood loss, shorter learning curves and increased number of retrieved lymph nodes. However, as many case series, including a recent multicenter study, have revealed, higher cost and longer operation time are the major limitations of robotic gastrectomy. Furthermore, there are no results from well‐designed randomized clinical trials comparing the two procedures. New procedures in much more technically demanding cases will test the genuine benefits of robotic gastrectomy. Within a decade after the initial reports describing the use of robots for the treatment of early‐stage gastric cancer, robotic gastrectomy has been found to be a safe and feasible alternative to conventional laparoscopic gastrectomy.2The indications for robotic gastrectomy are same as those of laparoscopic gastrectomy for gastric cancer. Initial indications for robotic gastrectomy were early gastric cancers without evidence of lymph node metastasis based on clinical diagnosis. It was expanded to include clinical stage T1‐2 cancers with or without perigastric lymph node metastasis, except for lesions for which endoscopic submucosal dissection (ESD) was indicated.To determine the proximal resection line for R0 resection, preoperative endoscopic placement of radiopaque hemoclips or intraoperative endoscopic localization is required, especially for small or non‐palpable tumors.33.1Overall, several reports documented that operative time was significantly longer for the robotic procedure ranging from 202 to 439 minutes compared with 171 to 361 minutes in laparoscopy3.2Many reports comparing robotic and laparoscopic gastrectomy revealed that there is significant reduction in blood loss with a range of 46–176mL with robotic approach and 34–212mL with laparoscopic approach3.3Most publications comparing robotic with laparoscopic gastrectomy demonstrated similar complication rates Table . A recen3.4Most investigators found no differences in length of hospital stay when they compared robotic with laparoscopic gastrectomy Table . A recen3.5Higher cost has been a consistently reported disadvantage of the robotic approach for gastric cancer. A recent prospective study demonstrated that the cost of robotic surgery was US$4490 more than that of laparoscopic surgery. The Korean National Health Insurance System covers perioperative care for both procedures. Although most of the operation costs for laparoscopic gastrectomy are covered by national insurance, none of the operation costs for robotic gastrectomy are covered. Thus, the actual cost charged to patients was US$7326 more for the robotic than for the laparoscopic group.3.6One suggested advantage of robotic surgery is its short learning curve compared to laparoscopic surgery. Thus, from the initial experience, robotic surgery can be carried out safely if it is conducted by a surgeon experienced in laparoscopic surgery. The learning curve of robotic gastrectomy demonstrates a quicker adaptation with most studies reporting 11‐25 cases to be sufficient for experienced gastric cancer surgeons,4As the use of robotic surgery in gastric surgery is relatively recent, it is a bit early to confirm the long‐term oncological results of robotic gastrectomy compared to laparoscopic gastrectomy. Oncological outcomes other than survival or recurrence, such as the number of lymph nodes harvested and margin status, are reported to be similar between robotic and laparoscopic approachesAnother comparative study revealed that the robotic gastrectomy group had a significantly higher number of harvested second‐tier lymph nodes than did the laparoscopic group, whereas first‐tier lymph node number did not differ between the two groups. As for tumor recurrence, it was 4.2% in the robotic and 7.1% in the laparoscopic group during a follow‐up period of 15 and 19 months, respectively.5Since robotic gastrectomy for gastric cancer was first carried out in 2005 at Severance Hospital, Yonsei University Health System, we have carried out over 1000 robotic gastrectomies, so far. The number of robotic gastrectomies has tended to increase  and 16 mL (P=.027), respectively. Number of retrieved lymph nodes increased in later cases (P<.001). Time to first flatus was statistically different in the two groups (P<.001) but initiation of soft diet was not statistically different (P=.221). There were four (0.3%) mortalities, two in the initial period and the others in the later period. Overall, results of robotic gastrectomy in our hospital demonstrated acceptable outcomes. Nowadays, robotic gastrectomy is one of the routine procedures for the treatment of gastric cancer in our hospital.We compared surgical outcomes of our experience of robotic gastrectomy with early  and later (after 500 robotic gastrectomies) robotic gastrectomy carried out between 2005 and 2015 Table . Baselin66.1The da Vinci Xi Surgical System  is a relatively new robotic system that is expected to overcome the limitations of the previous platform. Unlike the da Vinci Si Surgical System , the Da Vinci Xi System offers better anatomical access in multi‐quadrant surgical access because of the overhead boom rotation without axis limitation.Another new platform is the da Vinci Single Site Surgical System  robot surgery which aims to be even less invasive than the conventional robotic system. It is designed to allow robotic surgery to be carried out in a virtually scarless manner. With the use of a single‐port system, semi‐rigid instruments are used through the curved instrument cannulae to minimize external collision of instrument and camera arms. This new system has overcome the ergonomic disadvantages of conventional single‐port laparoscopic surgery, although current semi‐rigid or wristed devices are not sufficient to carry out complex operations. However, this has the potential to improve the outcomes of reduced or single‐port robotic gastrectomy. However, as it is a relatively new system, this needs further evaluation.Apart from systemic changes, various instruments were developed, such as stapling devices, vessel sealing system. A linear stapler was incorporated into the robotic system that can be controlled by the surgeon at the console without the help of an assistant Figure . Althoug6.2Robotic platform allows the integration of functional imaging such as the use of near infrared imaging after injection of indocyanine green. Near infrared imaging is used as a navigation tool for tumor localization and lymph node dissection Figure . Combine6.3Obtained intraoperatively or preoperatively, computed tomography and magnetic resonance imaging scans reconstructive images are used as a guide for primary tumor or lymph node dissection by incorporating them into the robotic system.6.4Endoscopic interventions have evolved significantly in recent years going from a diagnostic tool to an alternative to radical open surgery in early gastric cancer patients who fit the indication for endoscopic mucosal resection.7Robotic technique has been proven to be safe and feasible for use in gastric cancer surgery instead of the laparoscopic technique. Also, with the advancement of robotic technology, treatment could be extended to cover more advanced cases of gastric cancer to improve the quality of lymph node dissection. However, more evidence is needed to determine the actual benefits and cost‐efficiency. In addition, continued development of robotic technology is still required to achieve a better environment for improved surgery and the field of gastric cancer surgery is the exemption.Conflict of Interest: The authors declare no conflict of interest.


Patient dosimetry studies in diagnostic radiology in Nigeria have been on measurement of entrance skin dose and effective dose. Another important and easy to measure radiation dose descriptor that could be used to assess patient dose in radiological procedures is dose area product (DAP). Knowledge of DAP with location and projection of X‐ray beam allows direct calculation of organ dose and effective dose. In this study, DAP for commonly performed radiological examinations  in four diagnostic centers in Nigeria were determined. These centers comprise of three classes of health care center namely tertiary, private, and specialist hospitals. Mathematical method was used to determine DAP received by 336 patients undergoing radiological examinations at the selected diagnostic centers. The DAP received by patient from each radiological examination varies from center to center. The range factor (RF) of DAP for individual patients ranged from 1.55–4.56, while RF of DAP among the selected centers was 2.27–55.84. The highest RF of DAP (55.84) was obtained from X‐ray examination of the chest. This variation was due to the application of anti‐scatter grid, and high kVp and high mAs values for chest examination by only one of the centers. The very wide variation in DAP found among diagnostic centers in this survey showed that there is need to harmonize radiological techniques of common X‐ray examination among different diagnostic centers. This would ensure optimal protection of patient against excessive radiation dose.PACS numbers: 87.53.Bn; 87.59.B Also, DAP is useful for continuous quality assurance, as well as analysis of performance of X‐ray machines.Dose area product (DAP) is a product of surface area of patient that is exposed to radiation at the skin entrance multiplied by the radiation dose at this surface. Measurement of dose area product is suitable for achieving optimum degree of safety during radiological examination of patient. DAP is a valuable radiation dose descriptor because radiation‐induced bioeffects are directly related to both the magnitude of the radiation dose and the total amount of tissue that is irradiated.1 Also This is because the amount of radiation dose delivered to the skin of the patient determines both the stochastic and deterministic risks. The measurement of entrance surface dose with thermoluminescence dosimeter (TLD) has been shown to be laborious, capital intensive, and potentially intrusive, especially when large numbers of patients are involved in the survey. This made dosimeter‐based entrance surface dose measurement in routine X‐ray examination quite expensive for centers with limited resources. The adoption of a mathematical method for dose determination provides an avenue for greater output with respect to patient dose information. A study by McParland has shown that entrance skin dose can be estimated from dose area product with an accuracy of 30%–40%. Apart from being useful for estimating entrance skin dose in routine X‐ray examination, knowledge of DAP, as well as location and projection of X‐ray beam, can also be used to estimate effective dose, a quantity mostly used to assess stochastic risk from nonhomogeneous irradiation. DAP is easier to measure than entrance skin dose (ESD) and effective dose, especially in routine X‐ray examinations. Among several indirect methods employed for practical estimation of effective dose in conventional radiology and fluoroscopy is dose area product.Dose area product could be measured by two methods, namely: (i) direct measurement through the use of a transmission ionization chamber at the surface of the X‐ray tube collimator; and (ii) by mathematical approach (indirect). The mathematical approach involves the product of irradiated area of the patient and radiation dose incident at the surface. In conventional diagnostic procedure, the entrance surface dose is considered a useful first approach in measurement of radiation exposure to patients.2 This However, the dose area product received by patients during the examination procedure is not known. This present study is aimed at measuring dose area product received by patients undergoing common radiological examinations in some diagnostic centers in Nigeria. It is anticipated that the results from this study would provide useful means of estimating DAP and effective dose received by patients during routine X‐ray examination, thereby providing easy and timely patient dosimetry in diagnostic radiology. The results of the present study were compared with DAP values published in literatures for similar radiological examinations.In Nigeria, most of the studies on patient dosimetry in routine X‐ray examinations are usually dosimeter‐based measurement of either ESD or effective dose.,,9 This study was carried out in four diagnostic centers in Nigeria. These centers were comprised of tertiary hospitals (T), private diagnostic center (P), and a specialist hospital for women and children (S). The centers include University College Hospital (UCH), Ibadan (T); Obafemi Awolowo University Teaching Hospital Complex (OAUTHC), Ile‐Ife (T); TwoTees diagnostic centre (TDC), Yemetu Ibadan (P); and National Hospital Abuja (NHA) (S). Therefore, the patients considered in this study were limited to those whose weights are within the range 60–80 kg. The radiological examinations considered in this study were abdomen, chest, lumbar sacral joint (LSJ), paranasal sinus (PNS), pelvis, and skull. These X‐ray examinations are considered to be the most common X‐ray examination performed on patients worldwide. The transmission ionization chamber required for direct measurement of DAP was not available at any of the centers selected for this study; therefore, the mathematical method, which is the alternative option for centers without transmission ionization chamber, was used in this study. Some of the quantities required for calculation of DAP for each patient include tube loading (mAs), tube voltage (kVp), focus to skin distance (FSD), focus to film distance (FFD), collimator size (beam area), and beam output of X‐ray machine. The body mass index (BMI) of all patients was also calculated. The BMI, which was derived from weight/(height)2, is a useful classification scheme for the size and shape of a person. In this present study, DAP was calculated using the following equation:L is the tube loading expressed in mAs; Do is the normalized beam output in mGy/mAs at 1 m; FSD is the focus to skin distance, and A(FSD) is the cross‐sectional area of the beam on the skin of the patient. The beam output (mR/mAs) of X‐ray machine was measured in all the centers with noninvasive X‐ray test device model 4000 M+ . The calibration of the X‐ray test device issued by the manufacturer was still valid at the time of this study. The distance between the radiation source and the detector was initially set at 60 cm to prevent back scattering of radiation, before reaching the detector. The inverse square law relation (Iα1/d2) was used to determine the beam output (mR/mAs) at 100 cm. A conversion factor of 0.00873 was applied to convert the beam output from mR/mAs to mGy/mAs. The radiographic films used in all the centers selected for this study was Kodak  with medium speed of 200. All data from patients and X‐ray machines were analyzed with SPSS 16.0 for windows.These centers were chosen for the study because of the large workload of patients they recorded per day. Apart from this criterion, all the centers, except NHA, are referral centers for routine chest radiography for most health care centers in the South Western region of Nigeria. From each center, information about the X‐ray unit was obtained from the manufacturer's manual available at each center. This information includes manufacturer's name, model of the X‐ray unit, year of installation, film type/speed and tube filtration. A total number of 336 patients who consented to participate were enrolled in this study. The selection criterion was based on weight of the patient. This is because various authors have observed that patient size influences dosimetry results; for uniformity in sizes, it has been suggested that only patients whose weights are within the range of 60–80 kg should be included in a patient dose survey.,11 TmGy cm2) obtained from UCH, OAUTHC, TDC, and NHA was 100–783, 1663–7584, 122–634, and 113–694, respectively. The range factor of DAPs for individual patients for each of the radiological examination considered in this study is presented in Table The beam output (μGy/mAs) of X‐ray machines measured at tube voltage 80 kVp at each center is presented in Table  DAP is a surrogate of measurement for the entire amount of energy delivered to patient by the radiation beam. Although most of the X‐ray machines considered in this study are aged, they are still providing clinical services to Nigerian patients. Hence, the need to measure DAP received by patients during the procedure and thereby assess the performance of these old (> 15 years) X‐ray machines.Dose area product (DAP) is a good indicator of radiation risk to patient and not just absorbed dose received by patient during X‐ray examination. This is because DAP reflects not only radiation dose to patient, but also the area of tissue irradiated.15 DAP Of all the X‐ray tubes considered in this study, only the unit at OAUTHC contained total filtration (1.7 mmAl) that is below the range of values (2.5–4.3 mmAl) recommended for a good radiological practice, as reported in the UK. The beam output of X‐ray machines considered in this study was found to be very low when compared with beam output of similar but recently manufactured X‐ray machines reported in the Sudan survey. The technological advancement involved in the recently manufactured X‐ray units could contribute to this variation in beam output. When compared with a beam output measured at similar kVp in one of the teaching hospitals ) in the Sudan, the percentage of the beam output measured at UCH, OAUTHC, TDC, and NHA was found to be 24%, 11%, 10%, and 25%, respectively, of the values obtained in the Sudan. It is important to note that all the X‐ray machines considered in the Sudan study were installed between 2003 and 2005.As presented in Table 17 Of  However, the study sample is within age range considered in Malaysia (14–92 years), UK . The weight limit of 60–80 kg (mean 70 kg) was used as a criterion for selection of patients. This weight range is adopted to eliminate patient size factor, which usually influence patient's dosimetry results. The BMI of the study sample was found to be in the range of 21–26. All the patients who satisfied the weight criterion at OAUTHC at the time of this study were those with chest X‐ray examination. In all the centers, chest X‐ray examination has the highest frequency of radiological examination. It is well known globally that chest radiography is common and is usually the most patronized examination. The present study sample has 204 (61%) males and 132 (39%) females.The age range (18–90 years) of patients considered in this study is wider than the previous patient dose survey (40–85 years) conducted in Nigeria.7 Howe and Malaysia (55–125 kVp). In the case of tube loading (mAs) settings, the range of values selected for most projections in this study (9–300 mAs) were within the values reported in the UK survey (5–485 mAs) but higher than those selected in Malaysia (9–122 mAs). The variation in tube loading was due to patient's size. For instance, the patients considered in Malaysia were light weight (60 kg) as compared with those in this study (60–80 kg) and the UK (65–75 kg) surveys. The range of values of FFD (90–150 cm) and FSD (58–139 cm) obtained from this study were within the optimum values of FFD (80–210 cm) required for good geometric image sharpness reported in Sudan. The technique of applying anti‐scatter grids for a given type of X‐ray examination was similar in all the centers except for chest examination, where only one centre, OAUTHC, applied anti‐scatter grids.In all the centers, Kodak films with medium speed of 200 were used. One would expect all the centers to select exact exposure parameter for similar X‐ray examination since the film speed is similar, but this is not the case. As seen in Table ,21 a661 mGy cm2), TDC (451 mGy cm2), and NHA (694 mGy cm2) diagnostic centers are within the UK National reference doses (2600–3000 mGy cm2). The lowest DAP (109 mGy cm2) obtained for chest PA and LAT examinations was observed at UCH, while the highest (3970 mGy cm2) was obtained at OAUTHC. The value obtained at UCH is within the UK National reference doses (110–120 mGy cm2), whereas the DAPs obtained from other centers — namely OAUTHC (3970 mGy cm2), TDC (168 mGy cm2), and NHA (258 mGy cm2) — are higher than the UK National reference doses. The use of high kVp (100–110) technique and high mAs values (80–200) at OAUTHC for chest X‐ray examination could be responsible for the very high DAP (3970 mGy cm2) obtained at the center, as compared with other three centers that did not apply anti‐scatter grids. The DAPs obtained for AP and LAT lumbo sacral joint (LSJ) examination at UCH (378 mGy cm2), TDC (333 mGy cm2), and NHA (585 mGy cm2) are within the UK National reference dose (2550–3000 mGy cm2). Similarly, the DAPs obtained for AP and LAT pelvis examination at UCH (332 mGy cm2), TDC (634 mGy cm2), and NHA (486 mGy cm2) are within the UK National reference dose (2100–3000 mGy cm2). The DAP obtained for PA and LAT paranasal sinus (PNS) examination at UCH (the only center that had patients for this examination during the period of the study) was 166 mGy cm2. DAP for PNS examination was not reported in the UK National survey report. The DAPs obtained for AP and LAT skull examination at UCH (433 mGy cm2) and TDC (153 mGy cm2) are within the UK National reference dose (635 mGy cm2).In Table The range factor (RF) used in this study is the maximum‐to‐minimum ratios of DAP values obtained from each of the radiological examination for individual patients and among the selected centers. As seen in Table The dose area product (DAP) received by patient from common radiological examinations , pelvis, paranasal sinus (PNS), and skull) in four diagnostic  centers in Nigeria have been determined using mathematical method. The calculated dose area product (median) received by patient from most of the X‐ray examinations per center are within the values (mean) reported in the UK National reference doses. The only exceptions were the DAP values received from chest X‐ray examination, which was higher at OAUTHC, TDC, and NHA. Among these three centers, the DAP obtained from chest X‐ray examination at OAUTHC was very high and the increase was traceable to the use of high kVp technique with high mAs values.The very wide variation of DAP (2.27–55.84) obtained among the selected centers suggested that there is need to harmonize radiological techniques of common X‐ray examinations among diagnostic centers in Nigeria. This would ensure optimal protection of patient during radiological procedure. This study has shown that mathematical method could be adopted in routine medical X‐ray examination for quick determination of dose area product received by patient during the procedure. Furthermore, with the use of appropriate conversion factor, entrance skin dose and effective dose can easily be estimated from calculated dose area product. Future study is aimed at analyzing the impact of increased effective dose due to the combination of the age of X‐ray units used and the technique factors used. In conclusion, the authors wish to recommend that diagnostic X‐ray centers should avoid the use of X‐ray tube greater than 15 years old from the date of manufacture, and the use of high kVp technique must be accompanied with low mAs values for optimal radiation protection of patient.The authors wish to express appreciation to the International Atomic Energy Agency, (IAEA) Vienna, Austria and The Abdus Salam International Centre for Theoretical Physics, ICTP, Trieste, Italy, for sponsoring one of the authors in training on Radiation Protection in Diagnostic and interventional radiology, Nairobi, Kenya and Dosimetry in Diagnostic Radiology and its Clinical Implementation, Trieste, Italy. The IAEA fellowship training acquired at the University of Texas, MD Anderson Cancer Center, Houston, Texas, USA is highly appreciated. Also, the cooperation of the patients, radiographers and the management of all the selected centers is greatly appreciated.