As citizens, patients and family members are participating in numerous and expanding roles in health system organizations, attention has turned to evaluating these efforts. The context‐specific nature of engagement requires evaluation tools to be carefully designed for optimal use. We sought to address this need by assessing the appropriateness and feasibility of a generic tool across a range of health system organizations, engagement activities and patient groups.We used a mixed‐methods implementation research design to study the implementation of an engagement evaluation tool in seven health system organizations in Ontario, Canada focusing on two key implementation outcome variables: appropriateness and feasibility. Data were collected through respondent feedback questions (binary and open‐ended) at the end of the tool's three questionnaires as well as interviews and debriefing discussions with engagement professionals and patient partners from collaborating organizations.The three questionnaires comprising the evaluation tool were collectively administered 29 times to 405 respondents yielding a 52% response rate . The questionnaires' basic properties were rated highly by all respondents. Concrete suggestions were provided for improving the appropriateness and feasibility of the questionnaires (or components within) for different engagement activity and organization types, and for enhancing the timing of implementation.Our study findings offer guidance for health system organizations and evaluators to support the optimal use of engagement evaluation tools across a variety of health system settings, engagement activities and respondent groups. Developed by researchers and public and patient engagement practitioners, the goal of the PPEET was to provide a generic evaluation tool that could be used in a variety of health system organizations to evaluate and continuously improve the quality of public and patient engagement (PPE) activities. During its early development, the PPEET underwent usability testing with a limited group of respondents and end‐users (including patients and members of the public) who provided feedback on the structure, layout, comprehensibility, ease of use and overall utility of the survey.1.1participant survey aims to assess the processes, outputs and perceived impacts of engagement activities from the perspectives of citizens, patients and family members who may have various roles in the engagement process . The project survey aims to evaluate the planning and execution of the engagement activity from the perspective of engagement implementers . Finally, the organization survey aims to assess the culture and practices supporting public and patient engagement from the perspective of senior management and leadership in organizations . Each survey is structured around four core principles of “quality engagement” informed by an evidence synthesis and expert input: (a) integrity of design and purpose; (b) influence and impact; (c) participatory culture; and (d) collaboration and common purpose.The PPEET is comprised of three surveys, each aimed at different target groups for evaluation. The 2appropriateness ; and (b) feasibility (the extent to which the tool could be implemented in a particular setting).We used a mixed‐methods implementation research design2.1Study collaborators included early adopters of the PPEET (i.e. organizations using or interested in the tool immediately following launch), selected using the following inclusion criteria: organizations with different health system mandates , and organizations serving different types of communities or populations . The final group of seven collaborating organizations included large, urban, academic health science centres/networks (N = 3), provincial and/or regional health quality and integration organizations (N = 3), and one community‐based health services organization N = 1; Table ; Table 12.2In consultation with the research team, staff members within each of the collaborating organizations, identified the engagement activities that would be evaluated and oversaw the recruitment of citizens, patients, family members and staff to complete the surveys. The research team had no direct involvement in the recruitment process or contact with survey participants. All individuals involved with each of the selected engagement activities were recruited to participate in the survey. Recruitment methods varied by organization; each organization documented their recruitment process including the number of individuals approached to complete a survey and the recruitment strategies used.2.3Each of the three PPEET questionnaires contains a number of Likert‐scale questions  and a small number of open‐ended questions . A separate feedback survey was added to each evaluation questionnaire to assess respondents' perspectives on the appropriateness (Questions 1‐5 and 7) and feasibility of the questionnaire (Questions 6 and 7) using both scaled and open‐ended questions (see Appendix Organizations could opt to collect the survey data themselves or have the data collected directly by the research team through an online survey platform (LimeSurvey). Organizations collecting data shared it securely with the research team. When the online survey platform was used, the research team programmed the survey and shared a survey link with the organization, which was distributed to potential respondents. Completed surveys were stored directly on the secure online platform. No identifying information was collected through the survey, ensuring the anonymity of respondents.2.4Following each implementation, a report summarizing the results of the survey was shared with the partner organization. Organizations were encouraged to share evaluation results with the engagement participants. A member of the research team completed a 15‐ to 30‐minute debriefing call with the PPE project lead and/or the public/patient representative in each partner organization to discuss the PPE activity evaluated and the process used to implement the survey . During these calls, feedback on the appropriateness and feasibility of the tool was collected from the implementer's perspective . Additional feedback on the tool implementation process was collected through three advisory committee meetings held over the 1.5‐year project.2.5P‐values of <.05 were considered statistically significant). Individual participant responses to each open‐ended question were collated by question and coded to common themes across questions. Coding reliability was ensured through an iterative process where the primary coder (SK) and principal author (JA) met several times during the development and application of the coding scheme to review independent coding of selected data excerpts and resolve inconsistencies. Coding reliability was further corroborated by a third team member (LT) in the later stages of analysis. The results were shared with the Study Advisory Committee during an in‐person meeting for the purposes of member‐checking and additional discussion and reflection.PPEET feedback survey data were analysed using descriptive statistics for the quantitative components and qualitative thematic analysis for the open‐ended questions.3Each of the PPEET instruments was implemented in at least four of the seven partner organizations and between 1 and 7 instances within each Table . Results3.1Each partner organization implemented the participant survey at least once and as many as seven times over the study period. In total, 271 participant surveys were administered across the 7 organizations and 17 engagement activities and 152 surveys were completed. Of these, 131 respondents completed at least two of the feedback questions, which are the focus of our analysis  activities stated most frequently that important questions were missing (25.0%) compared to the other two groups (Table P = .02) and those from community‐based health system organizations stated most frequently, although not statistically significant, that the questions were hard to understand (25.0%)  Table .3.1.2Over half of respondents Table  providedMajor areas of feedback focused on the appropriateness and feasibility of the survey and specific sections or items within it, and the need for the tailoring to specific contexts. Minor areas of feedback included requests for additional questions to allow for more detailed exploration of the engagement process, minor wording changes and a request for “not applicable” response options.Although those who participated in short‐term engagement activities felt that questions in this survey “were valid and in‐scope of the activity” , many others questioned its appropriateness for longer‐term and KTE activities.This survey is evaluating approximately 10 meetings and doesn't lend itself well to that assessment…some meetings diversity of opinions was sought, sometimes not. The questions seem better directed to a one‐time, one‐topic focus group rather than an ongoing council. For respondents who were involved in longer‐term engagement activities such as councils and committees, the survey presented challenges in determining the unit of engagement to be evaluated (i.e. a specific activity or meeting or the engagement process as a whole) and how to assess the features of multiple meetings when the quality of engagement might vary from one meeting to the next. This led a number of respondents to state that the survey was better suited to a one‐time activity, a view that was shared by the Study Advisory Committee.For KTE activities, respondents cited the challenge of questions that were “very broad, hard to relate to the [activity] format/context”  and, correspondingly, the need for them to be “more detailed and specific” .A small number of questions generated insightful discussions among respondents and within the Study Advisory Committee. A notable example was the statement “As a result of my participation in this activity, I have greater trust in [organization]”. Some respondents felt this question was difficult to answer and that it would “depend on whether we get responses” to the feedback provided . Others did not feel the question “resonated with the work of an advisor”  or they did not “understand the relevance of the trust question” further explaining that “I didn't distrust [the organization] in the first place and attending [committee meetings] would not impact my organizational trust even if I had issues” . To these respondents, trust was formed (and broken) at the individual clinic/practitioner level and not within patient engagement activities. Tool implementers agreed that trust was a complex construct to measure and likely influenced by why individuals became engaged in the first place. Many implementers felt the trust question should be removed from the survey.The optional demographics section at the end of the questionnaire also generated considerable feedback and discussion. This section includes standard questions that collect information about respondents' age, gender, income, education, membership in a vulnerable group (e.g. recent immigrants), and employment history in the health‐care sector. Many participants understood the purpose of including these questions and recommended minor modifications . Some, however, felt that these questions were intrusive, overly personal and irrelevant to their engagement activities. Some of this discomfort stemmed from uncertainty about “what [organizers] would do with this information”  especially when it came to questions about income and age. This also likely explains why over a third of respondents did not share their income information in this section of the survey. There were concerns that responses to these questions might be used to prioritize the perspectives of some over others. A particular concern raised by a respondent involved in a long‐term activity was how the survey findings would be anonymized as “the questions asked compared to the demographics of [those participating] make it very easy [for the respondent] to be identified” . Another noted that these types of demographics did not seem appropriate for the particular setting they were involved in, and that questions related to individual's health status and experience with the health‐care system would be more relevant.Preface this as to why you're [collecting] this, [that] you want to be sure you're hitting all demographics [with your participant group]. That could maybe help to ease people's fears.From the tool implementers' perspective, collaborating partners acknowledged the importance of collecting demographic information to provide insights about the diversity of those involved in their engagement activities. However, some echoed the concerns shared by participants regarding how the information would be used and their ability to protect respondents' anonymity, particularly in the context of committees where small numbers of patient partners are typically involved. Others raised concerns about respondent burden given that patients are often asked these types of questions in health‐care settings. To address these concerns, recommendations were made for being more selective and purposeful in the use of the demographic questions with rationales provided for the inclusion of these questions.Without opportunity for comment, my views would not have been explained. (Patient partner member of Study Advisory Committee)The thing I appreciate most is having text‐boxes…there's no survey on earth that's going to be able to ask all the right questions and even if they do…you can't share the nuances of your experience that way. A number of respondents used the open‐ended comments section to request additional questions or themes that could be explored about the engagement experience. Notably, many requested the inclusion of additional comment sections, some requesting open‐ended comment boxes to accompany each item in the scale. The inclusion of comment boxes was viewed as an important vehicle for providing context and nuance to their scaled responses.3.2The project survey was implemented by four separate organizations (1‐4 implementations each). Both short‐ and long‐term engagement activities were evaluated using the tool. The response rates for this survey were much higher than for the participant survey (89%); all respondents completed feedback questions and 94% contributed open‐ended comments). Organizations had some difficulty identifying engagement activities and initiatives to evaluate using the project survey resulting in a fewer implementations across and within organizations. As a result, data were not analysed at the level of engagement or organization type.3.2.1P = .04). Although three‐quarters of respondents (75%) reported that the results of this survey would be useful for their organization, over two‐thirds indicated that questions were not easy to understand (68.8%) which was significantly higher than the PPEET participant and organization questionnaires (P < .001), suggesting the need for significant revisions  and the instructions were clear and helpful (87.5%), and few felt important questions were missing (6.3%). Across all surveys, the project survey respondents were least likely to feel the layout was easy to work with It is a bit challenging for project staff to answer on behalf of leadership in the organization. Timing of doing the questionnaire is key  [It's] too soon to say if [participant] input will be used. Almost all respondents Table  providedI didn't find the questions entirely easy to understand ‐ I felt I had to read each carefully to ensure I knew what they were asking. Some of the questions were open to interpretation and too vague to answer specifically. Some questions seemed very similar and it wasn't clear what the distinction was between them. Other feedback focused on the lack of clarity of specific questions, the repetitive nature of the survey and the applicability of certain questions to their engagement context .it's kind of human nature…if we put [an item] on the checklist and we know that we're being evaluated by it, we're sort of directly and indirectly pushing people to do best practice if you know you're going to be evaluated on it at the end of the day, right?The length of the survey was of concern to some respondents who felt it was “onerous to complete” . Respondents felt that the number of questions overall could be reduced as well as the number of open‐ended questions more specifically. A desire for questions to “focus a bit more on more of a micro level”  was also communicated to make them easier for staff to respond to. A member of the Study Advisory Committee noted that the length of the survey presented challenges for staff to find the time to complete it and recommended using the survey as a guide for conversations with staff about the engagement activity. The survey's utility in encouraging best practices was also noted:3.3The organization survey was implemented by 5 of the 7 organizations but achieved the lowest response rate of the three (37%); all respondents completed feedback questions, and 35% provided open‐ended comments). Four of the organizations used it to evaluate their public and patient engagement work across the organization. One organization used it to evaluate engagement within a specific part of the organization.3.3.1As with the other two surveys, most respondents felt this survey was easy to use 95.3%), the instructions were clear and helpful (95.3%), and the layout was easy to use (95.3%). Some felt important questions were missing (14.0%) and most found the questions easy to understand (90.7%). Almost all (90.7%) thought the results would be useful for their organization  and that the questions were not easy to understand 18.2%) (Table .2% (Tabl3.3.2Just over one‐third (35%) of those who completed the feedback questions on the organization questionnaire provided open‐ended comments, compared to over 50% and 90% for the other surveys Table . Major f(CHSO‐1)Engagement is part of the fabric of a true community organization. This survey puts the concept of public and patient engagement as a separate entity, it is not and therefore the questions are not in some instances relevant. On the theme of the appropriate organization type, the organization survey was critiqued for not adequately capturing the approach to engagement in an organization with a strong community orientation.The relevance of the survey to smaller‐sized organizations was also questioned—specifically organizations where there are fewer resources to dedicate to engagement, which could influence the responses to the survey questions. A related question about the framing of the survey was raised by one of the hospital sector respondents who noted that the survey seemed to view engagement as needing “additional resources or infrastructure rather than as a thread through existing structures” (AHSC‐3).Identifying the “right” individuals to participate in the survey and ensuring that the questions were relevant to range and type of respondents who might complete it within organizations was also identified as important. For example, one individual felt that “some questions were also hard to answer because they're out of the scope of what a manager would know” (HSO‐1).As with the project survey, a number of questions were cited for improved clarity, framing or contextualizing. Notably, greater precision was requested about the level within the organization at which the survey is being targeted. For example, it was not clear if they should be responding “specifically about what's done on a programmatic level, vs portfolio or [organization] at large” (HSO‐1). Others noted that the survey did not always fit with how engagement was operationalized in their context. For example, two hospital respondents spoke of how the question assumes that engagement reports are available and sent out, and this is not always the case (either because they are shared in other ways or because they are not available).4Our results provide insights into the appropriateness and feasibility of a set of three questionnaires for implementation in a variety of health system organizations to evaluate different types of engagement activities. Overall, the questionnaires comprising the PPEET were viewed by survey respondents and evaluation practitioners as useful, easy to administer and reasonably complete. While these findings are consistent with the results from the early usability testing results that informed the development of the first version of the PPEET,https://ppe.mcmaster.ca). Across‐the‐board modifications include both formatting and design revisions. Expanded guidance documents were developed for both respondents and tool implementers to tailor surveys to appropriate engagement activities and respondent groups. More comprehensive modifications have been made to the participant and project surveys in response to our study findings. The participant questionnaire was split into two discrete modules to address concerns about the appropriateness of a single instrument for both short‐ and longer‐term engagement activities. The project questionnaire was split into three modules, each to be used at different times during the engagement implementation process: (a) during the planning of the engagement activity; (b) immediately following the activity; and (c) 3‐6 months following the activity. These changes have shortened the surveys and ensure that the right questions are asked at the right time. Only minor changes were made to the organization questionnaire mostly focused on an expanded guidance document to respond to lack of clarity about its purpose and to emphasize its purpose in relation to the other two surveys.The tool revisions and related guidance documents informed by this implementation research study are now available , to ensure their feedback can be provided anonymously and that it will not be dismissed or given lower priority based on who they are. This relates to a third key message regarding the need for continued attention to the core principles of high‐quality engagement and that these should be extended to its evaluation .Our study is not without limitations. Despite our efforts, the organization and project tools were not implemented in each of our collaborating organizations, limiting our ability to robustly explore differences by organizations or engagement activity type. Further, the participant survey was only implemented once within a community‐based health services organization with one type of engagement activity, limiting our ability to generate conclusive results about tool implementation specific to this setting. A further limitation was the structure of the feedback survey. The feedback survey included one open‐ended question and 5‐6 dichotomous questions (yes/no) which only prompted for qualitative responses to explain negative responses. Feedback questions were guided by previous work in this area,5This study provides insight into how the PPEET  can be more optimally implemented to evaluate a range of public and patient engagement activities within a variety of health system organizations. Working closely with different health organizations to understand the appropriateness and feasibility of the PPEET surveys provided valuable information about how to improve the PPEET in simple yet effective ways. We look forward to continued efforts to develop and rigorously assess the PPEET and other engagement evaluation tools to support and continuously improve the quality of engagement work carried out in health system organizations.The authors have no conflicts of interest to report. Click here for additional data file. Click here for additional data file.


To quantify the effects of the Bragg peak degradation due to lung tissue on treatment plans of lung cancer patients with spot scanning proton therapy and to give a conservative approximation of these effects.3 at different depths in the lung) were optimized without consideration of the Bragg peak degradation. These treatment plans were recalculated with the Monte Carlo code TOPAS in two scenarios: in a first scenario, the treatment plans were calculated without including the Bragg peak degradation to reproduce the dose distribution predicted by the treatment-planning system (TPS). In a second scenario, the treatment plans were calculated while including the Bragg peak degradation. Subsequently, the plans were compared by means of Dmean, D98% and D2% in the clinical target volume (CTV) and organs at risk (OAR). Furthermore, isodose lines were investigated and a gamma index analysis was performed.Treatment plans of five lung cancer patients (tumors of sizes 2.7–46.4 cmThe Bragg peak degradation leads to a lower dose in the CTV and higher doses in OARs distal to the CTV compared to the prediction from the TPS. The reduction of the mean dose in the CTV was − 5% at maximum and − 2% on average. The deeper a tumor was located in the lung and the smaller its volume the bigger was the effect on the CTV. The enhancement of the mean dose in OARs distal to the CTV was negligible for the cases investigated.Effects of the Bragg peak degradation due to lung tissue were investigated for lung cancer treatment plans in proton therapy. This study confirms that these effects are clinically tolerable to a certain degree in the current clinical context considering the various more critical dose uncertainties due to motion and range uncertainties in proton therapy. Since proposed for radiation therapy, ion beams are of increasing interest in radiation oncology , 2. In hFor early-stage NSCLC patients the outcomes achieved with proton therapy are similar to those achieved with stereotactic body radiotherapy (SBRT)  despite For locally advanced (stage III) lung cancer patients, virtual clinical studies showed that in proton plans it is possible to reduce the dose deposition in normal tissue, especially in the heart, compared to photon plans –5. AdditIn addition to the debatable benefits of proton therapy compared to SBRT in lung cancers, some difficulties in treating lung cancers with protons arise due to the underlying physics as well as the technical application of the proton beam. One of the main issues is the range of protons that depends on the material in the beam path: in case that the patient’s anatomy changes and hence is different during the treatment compared to the treatment-planning process, the range and hence the dose deposition can be different to that predicted by the TPS. Hence, the outcome of the treatment is vulnerable to changes in the anatomy of the patient as the patient moves, is not optimally positioned or the anatomy of the patient changes between fractions, e.g. due to a shrinkage of the tumor or weight loss –10. EspeAnother issue is that the range of protons is predicted based on X-ray CT images while the conversion of stopping powers from X-ray CT images is inaccurate , 13. FurA crucial topic in the proton therapy of lung cancer patients is motion management since interplay effects due to respiratory motion or motion of the heart combined with the precise application of actively scanned proton beams can lead to a severe underdosage of the target volume –20.Another uncertainty in proton therapy of lung cancer patients arises from the characteristics of the lung tissue itself: The heterogeneous structure of the lung tissue leads to a degradation of the Bragg peak and to a wider distal fall-off , 22. If Baumann et al.  introducIn this study the effects of the Bragg peak degradation were investigated on clinical cases for various anatomical locations of the tumor in the lung and different treatment plans. We chose simple field configurations so that the results can be used by a large variety of proton centers. The goal is to give upwards estimations for the dose uncertainty in the target volume and OARs. For that, we included also extreme cases  to quantify the maximum degradation effect in realistic patient anatomies.3 and 46.4 cm3. The tumors were located in the right lung in the upper lobe (two cases) or the central lobe (three cases). We chose the clinical cases to have tumors located in the center of the lung as well as tumors that are located near to soft tissue or OARs. In doing so we are able to investigate different depth of the tumor in the lung as well as the effects of the Bragg peak degradation on surrounding normal tissue and OARs. For two cases the tumor was located near to the spinal cord. No tumor was located directly at the thorax wall in order to always have lung tissue between the thorax wall and the tumor and hence in the beam path. The patients were originally treated with photons and retrospectively re-planned with protons for this study. We used different beam directions in the proton plans to generate different path lengths in the lung  using the non-linear universal proton optimizer, v.13.7.15. The total prescribed dose was 30 Gy (RBE) and the only planning objective was to deliver at least 95% of the prescription dose to at least 98% of the planning target volume (PTV). For small tumor volumes we accepted hot spots (up to 115% of the prescribed dose) in the PTV. The PTV was the clinical target volume (CTV) plus an isotropic margin of 3 mm, although most PTV concepts proposed in the literature –36 are fWe decided to investigate simple treatment plans consisting of only one single field coming from either 0°, 270° or 315°. We used different beam directions to generate different depths of the CTV in the lung. The distal spot spacing was 3 mm, the lateral spot spacing was 0.45 times the full-width-half-maximum (FWHM) in air. The FWHM for 70 MeV protons was 32.5 mm and for 221 MeV protons it was 8.1 mm.The different beam directions are shown in Fig. Although some of these beams may not be the best choice from a clinical point of view , we decided to investigate these cases anyway to give an upwards estimation for the effects of the Bragg peak degradation also for worst-case scenarios.The motivation for using simple treatment plans is to highlight the effects of the Bragg peak degradation. Furthermore, there is no gold standard in plan design for lung cancer patients, especially concerning the choice of number of fields and beam directions, although several proton centers have already treated lung cancer patients with protons , 32–34. In order to assess whether the results from this study can be used to estimate the effects of the Bragg peak degradation for more complex plans, we investigated two IMPT plans, one each for patient 1 and 5 as shown in Fig. Simulations were performed using the Monte Carlo code TOPAS (Tool for Particle Simulations) version 3.1.p1 , a toolkPmod: The greater the modulation power of a heterogeneous material like lung tissue the broader the Bragg peak and the less steep the distal fall-off as shown in Fig. mean, D98% and D2% in the CTV and OARs. Additionally, we investigated the differences in the dose distribution when combining the dose distributions from the single plans  for each patient to an added-up dose distribution to investigate the influence of the number of irradiated fields on the degradation effects.Each treatment plan optimized with Eclipse was recalculated in TOPAS in two scenarios: In the first scenario, each optimized treatment plan was calculated on the original CT data. Hence, this calculation corresponds to the prediction from the treatment-planning system. In a second scenario, the plans were recalculated while considering the Bragg Peak degradation. To do so, we used the mathematical model presented by Baumann et al. . The strIn a study by Witt  the moduTo clarify whether these results obtained with porcine lungs are applicable for human lung tissue, high-resolution CT images with a resolution of 4 μm of human lung tissue samples were investigated by Witt  and BaumBoth the measurements with porcine lungs and the investigation of human lung tissue samples indicate that the modulation power of lung tissue is in the order of some hundred micrometers. However, until now there is no possibility to determine a patient-specific modulation power for each region of the lung. Therefore, in this study we investigated the effects of the Bragg peak degradation based on modulation powers of 100 μm, 250 μm, 450 μm and 800 μm, covering the whole range of modulation powers found in the measurements of porcine lungs and the investigation of human lung tissue samples with some additional buffer to determine the minimum and maximum degradation effects in exemplary clinical cases. For the IMPT plans we only used a modulation power of 450 μm.In Fig. In Fig. The greater range of the 20% isodose lines shows the potential risk of an overdosage in OARs distal to the target volume. Especially for patient 3 and 4 in Fig. mean, D98% (the dose that is received by 98% percent of the volume) and D2% between the modulated cases and the non-modulated case for patient 1 are reported in Table 98% is taken to quantify the minimum dose received by a volume while the D2% is taken to quantify the maximum dose received by a volume. For the OARs the mean dose Dmean and the D2% as a quantification of the maximum dose are shown.To quantify the effects shown in Figs. mean, D98% and D2% in the CTV are smaller for the modulated cases compared to the non-modulated case and hence the prediction from the treatment-planning system. The differences increase with an increasing modulation power. The largest differences can be seen for the beam direction 0° (corresponding to the largest depth in lung) and the maximum modulation power of 800 μm. Concerning the OARs trachea and spinal cord, the doses deposited in the modulated cases are greater compared to the non-modulated case for the beam directions 270° and 315°. The differences increase with an increasing modulation power. The maximum difference in the mean dose Dmean is + 24% for the trachea as well as the spinal cord. However, these relative deviations correspond to low absolute deviations of 0.3 Gy and < 0.1 Gy, respectively. The largest difference for the D2% value for the trachea is + 24% and + 21% for the spinal cord. These deviations correspond to 1.5 Gy and 0.2 Gy, respectively. It can be seen, that the effects of the Bragg peak degradation on the OARs are almost non-existent for a beam direction 0° since in this case no OAR is positioned distal to the PTV. The effects on the trachea are largest for the beam direction 270°. For the spinal cord the effects are largest for the beam direction 315°.The mean dose Dmean, D98% and D2% for the CTV between the modulated cases and the non-modulated case are shown for the patients 2 to 5. The results are given for a modulation power of 800 μm to give an estimation of the maximum effects. Additionally, the results for a more realistic modulation power of 450 μm are given. The deviations between the modulated cases and the non-modulated case for the OARs are as small and negligible as for patient 1 and hence not shown for the other patients. As it is the case with patient 1, the dose coverage of the CTV in the modulated cases is lower compared to the non-modulated case.In Table mean as well as the D98% are roughly − 5%. For the D2% it is about − 4%. The average difference in the mean dose Dmean is in the order of − 2%, for D98% it is − 3% and for D2% it is about − 2%.For a modulation power of 800 μm the maximum differences in the mean dose Dmean, the D98% as well as the D2% are roughly − 3%. The average difference in the mean dose Dmean is in the order of − 1%, for D98% it is roughly − 2% and for D2% it is − 1%.For a more realistic modulation power of 450 μm the maximum differences in the mean dose Dmean, D98% and D2% for the CTV between the modulated cases and the non-modulated case when all three plans from the beam directions 0°, 270° and 315° are combined. As for the irradiation with one single field, in the combined scenario with three fields, the differences between the modulated cases and the non-modulated case are at maximum about − 5% for a modulation power of 800 μm. For a modulation power of 450 μm the maximum difference is about − 3%.Additionally, we looked at the differences in the mean dose DIn Table mean of the CTV was − 1% for patient 1 and a modulation power of 450 μm. For patient 5 it was about − 3%. For patient 1, the reduction of the mean dose of the CTV approximately corresponds to the average dose reduction for the simple treatments plans with beam directions 0°, 270° and 315° .When comparing the results from patient 1 for the beam direction 315° with the results from patient 5 for the beam direction 315° one can see that in both cases the tumor is at a depth of 3.6 cm  of protons is larger than 1.1 at the distal part of the Bragg peak . At the The Bragg peak degradation due to lung tissue is only one of various issues in proton therapy in general and in proton therapy of lung cancer patients in particular as mentioned in the introduction. Thus, the dose and range uncertainties due to this degradation shall be compared to these other uncertainties in order to quantify its importance in the current clinical context. In a study by Paganetti  an overv99 (dose that is received by 99% of the target volume). With a prescribed dose of 66 GyE this corresponds to relative deviations in the D99% of 3% to 18%. The maximum difference in the D98% found in this study was 3% for a realistic modulation power of 450 μm.Additionally, range and dose uncertainties arise when changes of the anatomy due to weight loss or a shrinkage of the tumor are not accounted for. Szeto et al.  analyzedAnother crucial issue in proton therapy of lung cancer patients is motion. Dowdell et al.  investigAt last, we want to introduce and discuss two possible PTV concepts to account for and to avoid an underdosage of the target volume due to the Bragg peak degradation: following the range shifts as shown in Fig. To avoid this larger range and additional dose deposited in normal tissue, another PTV concept might be used as depicted in Fig. For both PTV concepts an exact knowledge of the anatomy  is important to choose the appropriate values for the additional margin (case b) or the additional dose (case c). Furthermore, the knowledge of the modulation power within the lung tissue is important, since this defines the range and dose uncertainties connected to the Bragg peak degradation. Unfortunately, there is currently no solution to determine the modulation power in patients in-vivo. This is a critical issue still to be solved.mean in the CTV when optimizing the treatment plan without considering the degradation due to the lung tissue. Compared to the range and dose uncertainties in proton therapy of lung cancer patients due to the addressed reasons, the effects of the Bragg peak degradation are clinically tolerable to a certain degree in the current clinical context. However, these mentioned dose uncertainties are constantly being reduced which might change this clinical context. Hence, a consideration of the Bragg peak degradation could become more relevant in the future and would bring proton therapy for lung cancer patients closer to a high-precision therapy. The effects of the degradation might be accounted for in the treatment-planning process by applying a corresponding PTV concept as suggested in this study. What is more, this PTV concept and hence the dose deposition in the patient could be optimized when having a detailed knowledge of the lung tissue’s modulation power. In our opinion, the exact determination of this modulation power is one crucial issue still to be solved.Altogether, the effects of the Bragg peak degradation are at maximum about 5% concerning the underestimation of the mean dose Dmean in the CTV according to this study was about 5% at maximum for an extreme modulation power of 800 μm, a long distance travelled through lung and a small tumor volume. For a more realistic modulation power of 450 μm the maximum effect was only about 3% in terms of Dmean. For OARs the effect was negligible for the cases investigated. This study confirms that the effects of the Bragg peak degradation are clinically tolerable to a certain degree in the current clinical context considering the various more critical dose uncertainties due to motion and range uncertainties in proton therapy. Furthermore, these effects might be accounted for by using corresponding PTV concepts as suggested in this study.The effects of the Bragg peak degradation due to lung tissue on lung cancer patients were investigated. The maximum effect on the mean dose D


The aim of the study is to investigate the relationship between the spatial distribution of the selected medical equipment and the preventable mortality rate in the regions of the Slovak Republic. The main analytical approach is carried out through the cluster analysis based on a Euclidean distance technique in order to get similarity of the administrative divisions in form of a district and a pseudot2 approach aimed at the determination of a number of the districts in a cluster. A number of medical equipment had a rising tendency from the year 2008. The most extreme position according to a localisation distribution of the computed tomographs and the magnetic resonance imaging scanners is held by the Košice IV District at the level of 7.50630. From an angle of view of the preventable mortality, the Piešťany District holds the most extreme position peaking at the level of 10.97969 for the female sex and the Kežmarok District with the value of 9.44088. The study has the significant dissemination outputs for health policy interventions, especially to draw up regional health plans for computed tomography and magnetic resonance imaging deployment, mainly in locations with a high preventable mortality rate for both sexes. In the last decade, attention in measuring and evaluating the healthcare system has increased significantly in both the professional sphere and the scientific sphere. This topic is the subject of many research studies, being studied at a national level as well as a regional level in order to capture regional disparities and uncover critical bottlenecks in the healthcare system. Measurement of the efficiency of the healthcare system is methodologically very complex, due to variations in individual systems, different infrastructure, market dynamics, epidemiology, and demography of the country. Demographic forecasts are not optimistic and indicate an increasing prevalence of demand for healthcare as well as its cost. The aging of the population, the introduction of new diagnostic and treatment technologies gradually increase health spending of the countries. Strict budget constraints put pressure on policymakers and other stakeholders to introduce more systematic and efficient ways of measuring and evaluating healthcare systems in order to improve the health of the population and responsibility, management and resource efficiency in the healthcare system of the country. Quantification of the healthcare system efficiency is a cardinal problem in a majority of the countries. As several research studies have declared, the Slovak Republic healthcare system offers a wide scope of opportunities for improvement with the intention of enhancing efficiency ,2,3,4.In recent time, the Ministry of Health of the Slovak Republic has introduced the concept of stratification of hospitals, whose aim is to significantly improve institutional healthcare by the year 2030. So far, there are major differences in the quality of healthcare provided by the healthcare facilities in the Slovak Republic. This concerns the mortality rate, reoperation, and rehospitalisation of patients. Exploring the causal relationships between these components and the factors that affect them is also at the forefront. Finding more effective and systematic ways of measuring and evaluating healthcare systems requires discovering a number of analytical trajectories that relate not only to outcomes such as mortality rate, reoperation, and rehospitalisation, but also to the process parameters. This means the investigation of the effects of inputs—in this case, the deployment of selected medical equipment—on outcomes that are represented by preventable mortality in the studied area. This research trajectory makes it possible to evaluate the optimisation of healthcare availability in relation to its demand structures in the individual regions in the terms of healthcare requirements for different age categories, specialised and long-term healthcare, and the other specific areas. These fundamental facts create the motivation to carry out this study, whose main objective is to explore the relationships between the spatial distribution of medical equipment and preventable mortality. This type of mortality is selected because of an orientation in computed tomography and magnetic resonance imaging, which play an important role in a diagnostic process.The international importance of such research lies primarily in comparative aspects. There are clear trends in the healthcare systems, especially health and economic aspects of the usage of the medical equipment, while its localisation at a regional level as well as a national scale is subject to centralisation or decentralisation within the national healthcare system. The health needs of the regions must reflect the demographic characteristics of the population, the prognosis of its development, the economic and social aspects affecting health behaviour and thus, the demand for healthcare too. It is also necessary to examine the availability of healthcare not only in the terms of geographic and economic parameters, but also regarding the distribution of the specialised medical equipment, whose nonoptimal distribution may cause fluctuations in the development of mortality of the various diseases.The medical equipment is one of the determinants of the healthcare quality and it also influences the accessibility of the healthcare provision. Usually, the factors like numbers of patients, doctors, beds, and so forth, in the context of the development of the standardised mortality rate are often analysed, but there is a lack of the studies aimed at the preventable mortality with relation to an investigation of their relationship. Such research is done with an assumption that healthcare service is provided at the highest level as it could be at the time of the analysis. Hence, this analysis is aimed just right on the medical equipment and especially, the two most used pieces of the medical equipment aimed at diagnostic purpose. The essential aim of the analysis is to provide a valuable platform for national and regional policymaking to develop strategic framework concepts as well as to establish accurate criteria to identify the necessary primary and secondary prevention programmes for the region and to regulate the availability of healthcare that has a significant impact on preventable mortality.The structure of the paper is common as, firstly, it offers a general entrance into the topic in a form of the fundamental introduction. Secondly, the Background section involves several scientific sources that create a comprehensive literature review of the issues related to the examined topic. Thirdly, the Data and Methodology section offers information about the data inputted into the analysis and also about the methods and the approaches applied in order to get a precise desired outcome determined at the end of the Introduction section. Fourthly, the Results section introduces the analysis outcome followed by the fifth section, Discussion, where the main results are discussed with the other studies in this field. Finally, the Conclusion section offers substantial findings and, hence, it summarises the whole analysis and introduces potential further research.A number of strategies aimed at achieving an optimum combination of computed tomograph investments in the South Side of Chicago are explored in the study applying a linear programming technique . The resAn increase in the number of computed tomographs during the explored period led to a rise of the regional differences in their deployment and usage is conclude in another study . To incrThe experience of the health plan operator with the accreditation of imaging services and the demand for a supply of new services is offered in the study  with an Also, the impact of a geographic approach on the late breast cancer diagnosis is investigated in the study . In the The usage of imaging techniques in stroke suspected in Scotland is investigated in another study . The subThere are the authors who investigate geographic aspects in the distribution of medical equipment from a microeconomic point of view and the other authors from a macroeconomic point of view. There are several interesting findings offered by the study taking into consideration a macroeconomic point of view . The autThe macroeconomic study explores a relationship between the health system resources and the economic conditions of the Organisation for Economic Co-operation and Development member countries, extracting the factors related to the introduction of the imaging diagnostic equipment in each observed country . The autAn important criterion for purchase, deployment and usage of the health equipment in addition to an economic field is their increasing complexity. This is pointed out by the study, which states that it is important to understand the usefulness of the instruments and the methods for evaluation of the usability of the medical equipment, not only in the selection process, but also in the process of purchase .A review of a relationship between the efficiency of the hospitals and the usage of computed tomographs and magnetic resonance imaging scanners is brought in more detail in the study . The autOn the most important issues of management of the medical equipment usage in the public health sector in Benin is focused another study . BetweenAssessment of the availability of the healthcare technologies in Nepal is carried out in the study with a definition of the factors leading to optimum availability of the healthcare service and addressing of the problem areas . AlthougThis is also in line with the findings of the study, which is interested in the research of the healthcare facilities in the Republic of Turkey . These aThe experts also address an issue of the availability and the economic sustainability of local public healthcare facilities, and they look for ways to achieve higher quality healthcare through the usage of the technological innovations even in smaller regional healthcare facilities .There are the authors who see a problem in the incorrect specification of user requirements for the medical equipment , the othThere are also the studies calling for the importance of the health technology assessment and to take into an account the nonclinical areas ,24,25,26The interesting incentives to improve efficiency in this area are also provided by the study . The autThe Data and Methodology section offers a view on the data applied in the analysis and the methodology employed to carry out this analysis with the given data.The data applied in the analysis come from the National Health Information Center of the Slovak Republic and from the Statistical Office of the Slovak Republic. The data about the medical equipment are provided by the first institution, and it is involved in the annual report of the National Health Information Center about the medical equipment in the healthcare facilities. This analysis takes into consideration the numbers of the two medical equipment—the most expensive ones that serve in practice. These are computed tomographs and magnetic resonance imaging scanners.The data about the population are established on the year-end basis, that is, it is based on the situation valid on the 31st December of the individual year. The particular original table is marked om7009rr in Datacube , which sAlongside the scientific methods, a part of the methodology is created also by the territorial understanding of the explored area.The cluster analysis is employed to get a spatial classification of the individual districts of the Slovak Republic. As a hierarchical method of clustering, a hclust approach  is engag−P—pseudot2 value,−j—a rank of the cluster in the first computation,−q—a number of the clusters,−g—a rank of the district in the xC cluster,−gv—a vector of the observation of the g-th district in the xC cluster,−jc—a centroid of the first computation,−k—a rank of the cluster in the second computation,−h—a rank of the district in the yC cluster,−hv—a vector of the observation of the h-th district in the yC cluster,−kc—a centroid of the second computation,−l—a rank of the cluster in the third computation,−i—a rank of the district in the zC cluster,−iv—a vector of the observation of the i-th district in the zC cluster,−lc—a centroid of the third computation,−yn—a number of the districts in the yC cluster,−zn—a number of the districts in the zC cluster.The pseudot2 approach value is calculated as follows:−d1—the first district,−d2—the second district,−ED—the mutual Euclidean distance of the d1 district and the d2 district,−x1—the x coordinate of the d1 district,−x2—the x coordinate of the d2 district,−y1—the y coordinate of the d1 district,−y2—the y coordinate of the d2 district.Similarity is quantified by the Euclidean distance that is computed through the following formula:The essential explanation of the previously mentioned formula expresses similarity quantified in units of the Euclidean distance. The smaller distance between the districts is, the more similar they are. The original input data are normalised in order to get the applied dimensions comparable within the analysis.The fundamental legend for heat map says the darker colour is, the more dissimilar pair of the district it is and vice versa. Also, for the standard maps, the legend says that shade of the colour rises with an increasing number of the illustrated dimension.Preventable mortality is one part of a concept of avoidable mortality. It represents the specific diagnoses which mortality in the terms of causing death can be considered preventable from. Its structure is defined according to the document of Eurostat—the statistical office of the European Union . Definin−tuberculosis—A15 to A19, B90,−hepatitis C—B17, B18,−human immunodeficiency virus and acquired immunodeficiency syndrome—B20 to B24,−malignant neoplasm of lip, oral cavity and pharynx—C00 to C14,−malignant neoplasm of oesophagus—C15,−malignant neoplasm of stomach—C16,−malignant neoplasm of colon and rectum—C18 to C21,−malignant neoplasm of liver—C22,−malignant neoplasm of trachea, bronchus and lung—C33, C34,−malignant melanoma of skin—C43,−mesothelioma—C45,−malignant neoplasm of breast—C50,−malignant neoplasm of cervix uteri—C53,−diabetes mellitus—E10 to E14,−alcohol related diseases excluding external causes—F10, G31, G62, I42, K29, K70, K73, K74, K86,−illicit drug use disorders—F11 to F19,−ischaemic heart disease—I20 to I25,−deep vein thrombosis with pulmonary embolism—I26, I80, I82,−aortic aneurysm and dissection—I71,−influenza including swine flu—J09 to J11,−pneumonia—J12 to J18,−chronic obstructive pulmonary disorder—J40 to J44,−transport accident—V01 to V99,−accidental injury—W00 to W59,−suicide and self-inflicted injury—X60 to X84, Y10 to Y34,−homicide and assault—X85 to X99, Y00 to Y09,−misadventures to patients during surgical and medical care—Y60 to Y69, Y83.A whole set of the preventable mortality diagnoses is divided into the following 27 groups of the diagnoses:The groups of the diagnoses are sorted alphabetically according to their abbreviated designation for the first involved diagnosis.There is to note that because of the data availability for the whole explored period, a few three-digit diagnoses are substituted by two-digit diagnoses. The B17.1 diagnosis is substituted by the B17 diagnosis, the B18.2 diagnosis by the B18 diagnosis, the G31.2 diagnosis by the G31 diagnosis, the G62.1 diagnosis by the G62 diagnosis, the I42.6 diagnosis by the I42 diagnosis, the K29.2 diagnosis by the K29 diagnosis, the K74.0 diagnosis with the K74.1 diagnosis, the K74.2 diagnosis, and the K74.6 diagnosis by the K74 diagnosis, the K86.0 diagnosis by the K86 diagnosis, the I80.1 diagnosis with the I80.2 diagnosis and the I80.3 diagnosis by the I80 diagnosis, and the I82.9 diagnosis by the I82 diagnosis. This alteration does not influence the analysis outcome in any considerable way.The elementary territorial division of the explored area is established on the Nomenclature of Territorial Units for Statistics, which serves as the primary geocode standard for Eurostat—the main statistical office of the European Union . The ana−SK0101—the Bratislava I District,−SK0102—the Bratislava II District,−SK0103—the Bratislava III District,−SK0104—the Bratislava IV District,−SK0105—the Bratislava V District,−SK0106—the Malacky District,−SK0107—the Pezinok District,−SK0108—the Senec District,−SK0211—the Dunajská Streda District,−SK0212—the Galanta District,−SK0213—the Hlohovec District,−SK0214—the Piešťany District,−SK0215—the Senica District,−SK0216—the Skalica District,−SK0217—the Trnava District,−SK0221—the Bánovce nad Bebravou District,−SK0222—the Ilava District,−SK0223—the Myjava District,−SK0224—the Nové Mesto nad Váhom District,−SK0225—the Partizánske District,−SK0226—the Považská Bystrica District,−SK0227—the Prievidza District,−SK0228—the Púchov District,−SK0229—the Trenčín District,−SK0231—the Komárno District,−SK0232—the Levice District,−SK0233—the Nitra District,−SK0234—the Nové Zámky District,−SK0235—the Šaľa District,−SK0236—the Topoľčany District,−SK0237—the Zlaté Moravce District,−SK0311—the Bytča District,−SK0312—the Čadca District,−SK0313—the Dolný Kubín District,−SK0314—the Kysucké Nové Mesto District,−SK0315—the Liptovský Mikuláš District,−SK0316—the Martin District,−SK0317—the Námestovo District,−SK0318—the Ružomberok District,−SK0319—the Turčianske Teplice District,−SK031A—the Tvrdošín District,−SK031B—the Žilina District,−SK0321—the Banská Bystrica District,−SK0322—the Banská Štiavnica District,−SK0323—the Brezno District,−SK0324—the Detva District,−SK0325—the Krupina District,−SK0326—the Lučenec District,−SK0327—the Poltár District,−SK0328—the Revúca District,−SK0329—the Rimavská Sobota District,−SK032A—the Veľký Krtíš District,−SK032B—the Zvolen District,−SK032C—the Žarnovica District,−SK032D—the Žiar nad Hronom District,−SK0411—the Bardejov District,−SK0412—the Humenné District,−SK0413—the Kežmarok District,−SK0414—the Levoča District,−SK0415—the Medzilaborce District,−SK0416—the Poprad District,−SK0417—the Prešov District,−SK0418—the Sabinov District,−SK0419—the Snina District,−SK041A—the Stará Ľubovňa District,−SK041B—the Stropkov District,−SK041C—the Svidník District,−SK041D—the Vranov nad Topľou District,−SK0421—the Gelnica District,−SK0422—the Košice I District,−SK0423—the Košice II District,−SK0424—the Košice III District,−SK0425—the Košice IV District,−SK0426—the Košice-okolie District,−SK0427—the Michalovce District,−SK0428—the Rožňava District,−SK0429—the Sobrance District,−SK042A—the Spišská Nová Ves District,−SK042B—the Trebišov District.The list of the abbreviated codes applied in the analysis and the inserted figures for the separate districts is subsequent:The whole computation, the diagrams and the maps are produced by the R software environment . The rgdThe whole analysis output can be divided into three sections. The first one is devoted to the analysis of the medical equipment distribution over all the districts of the Slovak Republic. The second one is aimed at the preventable mortality rate of the female sex population and the third one at the preventable mortality rate of the male sex. Each part consists of a description of a situation at the beginning of the explored period in the year 2008, a situation at the end of the explored period in the year 2015, and a situation throughout the whole examined period between these years. A pair of the two most expensive medical equipment is created by computed tomograph and magnetic resonance imaging scanner. The computed tomograph serves to provide a tomogram that is a computed tomography scan, or in the other words, a computerised axial tomography scan. The magnetic resonance imaging scanner makes available to picture an inner situation of a human body. Sometimes, it is referred to as the nuclear magnetic resonance imaging scanner or very rarely as the magnetic resonance tomograph.As it is seen in As the first point after the above-mentioned figures, there is to note that the distances at the level of 0 are caused by the fact that there is a lot of the districts with zero medical equipment. That is why these districts keep the same level of mutual distance and they are visualised on the same horizontal level. The districts with dark coloured striped possess the extreme positions against the rest of the Slovak Republic meaning that the Bratislava I District, the Bratislava II District, and the Košice IV District create a specific group from a territorial point of view regarding their mutual similarity. Hence, they are ready to apply a potential specific healthcare policy which would be different from the general regional policy applied for the whole Slovak Republic. Having a look at the situations at the beginning and at the end of the examined period, they are very similar to the previously mentioned conclusion. From a point of view of the interpretation, they are almost identical.The following table shows the ten most extreme districts in a field of the medical equipment distribution for the beginning of the observed period in the year 2008, for the end of the observed period in the year 2015 and a mean situation of the whole observed period.There is to note that the Euclidean distance shown in the above-mentioned table represents a mean value of the Euclidean distance of the given district in a mutual pair to every other one district of the Slovak Republic. The similarity values demonstrate how long is a Euclidean distance between the particular districts. Its mean value is calculated from all the distances assigned to the singular district. The individual clusters are apparently evident. As As it is seen from the three previous figures, the examined medical equipment is localised very centrally in the terms of their concentration to the two largest cities of the Slovak Republic—Bratislava, which is the capital city, and Košice. Both cities are divided into several districts because of its level of population. Bratislava is created by the five districts, and two of them are highlighted—the Bratislava I District and the Bratislava III District. Košice is formed by the four districts, and its surrounding rural area is also represented by the own district. The Košice IV District is the featured district because of its large number of the equipment. A more illustrative view is offered by a successive triplet of the figures where the extreme districts are omitted from the legend scale of the maps.In the previously mentioned three maps visualised on The subsequent diagrams illustrated on As it is seen from a triplet of the previously mentioned heat maps, the preventable mortality similarity is considerably various among the districts of the Slovak Republic for the female sex. This implies a peculiar role of the regional healthcare policy because it should be tailor-made for the individual areas of the country in order to be as precise and as efficient as it is possible. There are visible the outliers which a specific policy should be applied on in order to get them into the regime of a remaining area of the country, because the more districts possess the outlying positions, the more complicated it is. Hence, it is determined which regional healthcare policy suits for them best. At the beginning of the explored period, the Piešťany District, the Považská Bystrica District and the Žilina District perform as the significant outliers, whilst the first one along with the Medzilaborce District stay at the extreme positions at the end of the examined period too. Unsurprisingly, both these districts keep their outlying position throughout the whole observed period and the Banská Štiavnica District with them too.The subsequent table shows the ten most extreme districts in a field of the female sex preventable mortality for the beginning of the explored period in the year 2008, for the end of the explored period in the year 2015 and a mean situation of the whole explored period.There is to note that the Euclidean distance shown in the above-mentioned table represents a mean value of the Euclidean distance of the given district in a mutual pair to every other one district of the Slovak Republic meaning it expresses a potential similarity to each district. As The above-mentioned maps appropriately illustrate the development of the similarity of the districts in a field of the standardised mortality rate of the preventable diagnoses for the female sex. A considerable shift to the most extreme values is seen in a case of the Medzilaborce District and the Žilina District. Also, the Banská Štiavnica District and the Čadca District are on a move to the maximum values. The Dunajská Streda District, the Liptovský Mikuláš, the Šaľa District, and the Zvolen District are the ones where a similar movement is visible. An opposite shift is seen in the Trnava District and partially in the Košice-okolie District too.The subsequent diagrams visualised on The outcome of the similarity heat maps is for the male sex different absolutely as for the female sex. The Tvrdošín District is the only district with an outlier attribute observing the beginning of the explored period. There are the four districts located at the extreme position at the end of this period—the Partizánske District, the Považská Bystrica District, the Kysucké Nové Mesto District, and the Svidník District. A look at the heat map of the whole explored period offers the most varying view certainly. None of the districts can be selected as the proper outlier.The succeeding table shows the ten most extreme districts in a field of the male sex preventable mortality for the beginning of the explored period in the year 2008, for the end of the explored period in the year 2015 and a mean situation of the whole explored period.The same legend as for As A situation is categorically different for the male sex as it is for the female sex. The following districts have moved to the extreme values—the Banská Štiavnica District, the Kysucké Nové Mesto District, the Malacky District, the Myjava District, the Partizánske District, the Považská Bystrica District, the Rožňava District, the Ružomberok District, the Rožňava District, and the Svidník District. Besides these districts, also the Bratislava III District, the Bratislava V District, the Košice I District, and the Košice IV District have got their distances higher. An opposite situation has occurred only the Tvrdošín District where its extreme value has been decreased. Overall, there are districts with an increasing number of distances, that is, becoming more dissimilar with their surroundings than vice versa.A focus of this research is not only on the avoidable mortality and within it on the preventable mortality, which is influenced by the availability of healthcare. It also includes the availability of medical equipment. Looking at the results of the analysis, the interesting findings can be seen. The number of computer tomographs and magnetic resonance imaging scanners in the individual districts has been increasing since 2008, with the exception of stagnation of a number of magnetic resonance imaging scanner in the last three years. Although there is a noticeable increase in the number of the explored medical equipment, its distribution within the districts is considerably uneven. These findings confirm the result of the cluster analysis. The extreme values in the terms of its distribution are achieved by the Košice IV District at the level of 7.50630 units of Euclidean distance, the Bratislava I District at 6.56821, and the Bratislava III District at 4.35243 throughout the whole explored period. This is related to the fact that there are large university hospitals and the specialised healthcare facilities in these districts who’s diagnostic and treatment processes are associated with the usage of this medical equipment. The outcome of the analysis of the preventable mortality rate during the same period point to the different regional distribution than the computed one regarding the medical equipment, both for the female sex and the male sex. The preventable mortality rate has developed differently within the individual districts throughout the observed period. The highest values are reached by the Piešťany District peaking at the level of 10.97969 units of Eucliden distance, the Medzilaborce District at 10.92476, and the Banská Štiavnica District at 9.99689. Regarding the sexes, the results of the preventable mortality rate are more heterogeneous in the male sex than in the female sex within the individual districts. There is also a complete alteration in the extremely ranked districts during the explored period. From a statistical point of view, the averaging of the data for the whole period is also an affecting factor. Development of the preventable mortality rate values has been uneven not only in a territorial point of view, but also from a time aspect. In many districts with a recorded increase in the mortality rate, there is a decline in several years, and vice versa. Among the extreme districts with the highest recorded preventable mortality rate, the Kežmarok District is placed on the first position peaking at 9.44088 units of Euclidean distance, the Banská Štiavnica District at 9.10647, and the Sobrance District at 9.09178. The following table offers a view on the districts, where there is an absolute lack of computed tomographs and magnetic resonance imaging scanners.As it is seen in The districts with at least one piece of the examined medical equipment show the lower levels of the preventable mortality rate in general. Moreover, Uneven distribution of the medical equipment over the country could also affect the regional disparities in a mortality rate development. In the period when the availability of computed tomography and magnetic resonance imaging is very limited, the introduction of a finding that an increase in computed tomographs leads to the regional differences in its deployment and usage is found in the study . AlreadyThere is a clear tendency to disseminate the outputs towards confronting their abundance with the quantifiable economic parameters also in many other research studies aimed at exploring the regional differences in the distribution of medical equipment. These parameters are examined by the several authors in the early stages, for instance in the procurement of the medical equipment , as wellHowever, research studies that confront the distribution of the medical equipment with the development of the mortality rate are absent. Looking at the core of preventable mortality, one of the possibilities of its elimination is higher availability of healthcare and a higher quality of its provision. This is also ensured to a greater extent by a higher level of the medical equipment usage. Therefore, it is important to look for a causal relationship between the condition and development of mortality and the distribution of the medical equipment. A high rate of the medical equipment usage in a given location should correspond to a low level of the preventable mortality rate and vice versa. If these relationships are not confirmed, it is important to examine other factors that cause such association. Health literacy and health behaviour, as well as a wide range of the socio-economic factors related to economic and social inequalities in the regions, are also highlighted. An interesting research trajectory would be to investigate the regional differences in the distribution of the medical equipment and preventable mortality within the least developed districts, which are also defined by the legal norm . It is eThere are several limitations to this study. Mainly, they are related to the source database. The data from the National Health Information Center on the medical equipment are obtained only at a district level in the most detail without the possibility of assigning them to the specific healthcare facility in the particular district of the Slovak Republic.Another limitation of the study is the type of medical equipment that is analysed. Although the numerous studies declare an influence of computed tomograph and magnetic resonance imaging scanner numbers on the condition and development of mortality of serious diagnoses, their number in the individual districts is recorded only in units, not at least in tens of units. This seriously limits a choice of an appropriate methodological procedure to investigate causal relationships between the numbers of this medical equipment and mortality, as for instance an increase by one unit from a basement at the level of one unit means a relative increase by 100%.Nevertheless, this study bears the significant dissemination outputs for health policy interventions, for instance, to draft regional healthcare plans for a deployment of the computed tomograph and magnetic resonance imaging scanner, especially in locations with the high preventable mortality rate. Specific prevention programmes would play an important role in this field. They should be a part of the policies that affect the regulation of a medical equipment deployment as well as the regulation of the financial resources necessary to maintain it. It is also important to create new action plans for healthcare technology management and health technology assessment. This is related to the fact that in addition to the previously preferred assessment techniques of health-related aspects of the medical equipment, nonclinical areas and the impact of medical devices on organizational processes have recently begun to be measured. These dimensions are also extremely important for improving the quality of healthcare, which is immediately reflected in the level and structure of morbidity and mortality. These consistent facts reaffirm the importance of health technology distribution assessment in relation to mortality reflecting the quality and availability of healthcare in the region.The limitations lie in a field of the data set partially. The main ambition of the analysis is to investigate the relationship between the medical equipment along with its localisation in the particular healthcare facilities over the districts of the Slovak Republic and the standardised mortality rate of the preventable diagnoses. However, such detailed data are not available from the National Health Information Centre. Another limitation is a lack of studies that declare and assess the level of the benefits of the diagnostic processes using the examined medical equipment. Hence, also a lack the studies to reveal a relationship between the mentioned diagnostic processes and the particular preventable mortality diagnoses. It would be beneficial to add also further information about the medical equipment. In general, use of the observed types of the medical equipment is a very demanding issue. A missing interconnection of the morbidity database and the mortality database performs as a key factor. There are no analyses, which use of the diagnostic medical equipment is investigated in relation to early reveal of the potential diseases in. A possible field to research is offered by the inspection of the various stages of the diseases with a concentration on the primary phase of the disease outbreak. This study could put pressure on the development of the above-mentioned healthcare database and their modification for their use in the analytical processes that could help to improve health policy plans and hence, it would be valuable to the international and national benchmark.The outcome of this analysis is offered mostly in a visualisation form. This makes it possible to better assess the relationship that is the primary subject of the research. The main aim of the study is to investigate the relationship between the spatial distribution of the selected medical equipment and preventable mortality in the regions of the Slovak Republic in the period beginning in the year 2008 and ending in the year 2015. The 27 groups of the preventable mortality diagnoses and the two types of the medical equipment, where computed tomograph and magnetic resonance imaging scanner belong, are examined within all the districts of the country. After exploration of a wide range of the international research studies, it is found out that the problem of the distribution of the investigated medical equipment is largely solved in the two research lines—as research of the geographic distribution of this medical equipment and as the evaluation of its efficiency. As many studies report, the efficiency of its usage depends not only on their number but also on the types of treatment and diagnostic processes that are set for its use. These processes are influenced by centralised or decentralised systems as well as many regulatory and stabilisation mechanisms in the healthcare system of the countries. Therefore, investigation of the causalities associated with the efficient usage of the medical equipment is very tricky. It is much more difficult to investigate the relationship between the usage of medical equipment and the mortality rate. Mortality is a complex and problematic indicator in terms of healthcare quality assessment. Its condition and development are influenced, among other factors, by the availability of healthcare and the availability of healthcare facilities. Hence, to explicitly quantify the ratio of the individual factors to its state and development is considerably demanding from a methodological point of view too.


MPC) on the Halcyon to detect errors, with comparison with the TrueBeam.To evaluate the ability of the machine performance check  tests that use a phantom placed on the couch and the linac's imaging system(s) to verify the beam constancy and mechanical performance of the Halcyon and TrueBeam linacs. In order to evaluate the beam constancy tests, we inserted solid water slabs between the beam source and the megavoltage imager to simulate changes in beam output, flatness, and symmetry. The MPC results were compared with measurements, using two‐dimensional array under the same conditions. We then studied the accuracy of MPC geometric tests. The accuracies of the relative gantry offset and couch shift tests were evaluated by intentionally inserting phantom shifts, using a rotating or linear motion stage. The MLC offset and absolute gantry offset tests were assessed by miscalibrating these motions on a Halcyon linac.IC Profiler and MPC, after intentional changes, was 1.3 ± 0.5% (for changes ≤5%). For Halcyon, the MPC test failed  when the beam symmetry change was over 1.9%. The accuracy of the MLC offset test was within 0.05 mm. The absolute gantry offset test was able to detect an offset as small as 0.02°. The accuracy of the absolute couch shift test was 0.03 mm. The accuracy of relative couch shift test of Halcyon was measured as 0.16 mm.For the Halcyon system, the average difference in the measured beam output between the MPC to identify errors in dosimetric and geometric parameters. These results showed that the MPC is sufficiently accurate to be effectively used for daily QA of the Halcyon and TrueBeam treatment devices.We intentionally inserted errors to evaluate the ability of the  These QA tests include checks of x‐ray output, energy, and beam profile constancy as well as image‐guided radiation therapy (IGRT) functionality as recommended by the American Association of Physicist in Medicine (AAPM) Task Group (TG) 142,The Halycon has a “virtual isocenter” where the patient (phantom) is setup outside of the treatment bore, and then moved to the true isocenter by couch motion. This movement is checked by the MPC for the Halcyon.TrueBeam systems include kilovoltage imaging, which was not available on the preclinical Halcyon 1.0 unit tested in this work.The Halcyon does not allow couch rotations.The MPC is part of a built in safety mechanism on the Halycon. On these, unit beams cannot be run in clinical mode unless the MPC has been run and passed on to that calendar day.The TrueBeam uses the isocal phantom, also used for imaging geometry calibrations, with a separate couch mount while the Halycon uses a similar phantom that is permanently attached to a couch mount.Varian Medical Systems  recently released the Machine Performance Check (MPC) system, which is a fully integrated self‐check tool for assessing the performance of the linac. MPC uses a vendor‐supplied phantom which is placed on the couch at the H2 position, using either a separate bracket or a bracket that is already attached to the phantom (depending on the system). Images of the phantom are acquired with various combinations of collimator positions, gantry angles, and couch positions through an automated sequence. Beam performance checks include beam output constancy, beam uniformity, and beam center shift. Geometry checks include the radiation isocenter size and a measure of coincidence with MV and kV imaging isocenters, as well as checking collimator and gantry readout accuracy, MLC and jaw positioning, and couch positioning accuracy. The MPC tests are executed as a special mode on the linac. All motions  are automatic, as is the analysis of the images. The MPC results are then presented relative to a baseline for the beam performance checks, and compared to absolute specifications for the geometric tests. Users are not able to modify the MPC results or thresholds but can set beam baselines. MPC is available for both the new Halcyon  and the existing TrueBeam platforms (version 2.0 and newer). The tests on these two treatment delivery systems are similar, although the vendor‐set thresholds vary between the systems. Other differences include the following:Two groups have previously evaluated the stability and sensitivity of MPC test for the TrueBeam system.2Here, we summarize each specific MPC test, and then describe how we intentionally inserted errors and evaluated the ability of the MPC to detect these errors. Specific details on the MPC system can be found in the publications by Clivio and Barnes and in the vendor documentation.To assess the ability of the MPC to detect changes in machine output or beam profile, we simulated errors by fully or partially inserting solid water into the beam path to change the linac's apparent output and symmetry. The MPC results were compared to measurements made with a 2D ion‐chamber array . Other groups have previously benchmarked this device for a variety of beam measurement, including profile measurements, symmetry, and flatness measurements, and relative output measurements.Note, when it was not possible to simulate errors, using external means , we miscalibrated the motions for the preclinical Halcyon unit only.2.A2.A.12 with the couch/MPC phantom retracted. A ratio image is calculated between the new image and a previously defined baseline image. The central 13.3 × 13.3 cm2 portion of this is then used for beam output and uniformity analysis. The idea of using this inner portion of the image is to reduce the impact of jaw (MLC) positioning on the beam constancy calculations.For both the TrueBeam and Halcyon linacs used in this study, the output and uniformity baselines were established after annual calibration measurements, following all instructions and advice in the Instructions for the User document provided by the vendor (Varian). The MPC beam constancy checks are performed with the gantry and collimator at 0°, the field size fixed at 18 × 18 cmOutput change is given as the average percentage change in detector response in this central region of the imager. The threshold of output change is ±4% for the Halcyon and ±2% for the TrueBeam. As with all MPC thresholds, these are set by the manufacturer and are not user adjustable.The uniformity change is defined as the variation between the highest and lowest ratio of pixel values (after high frequency noise filtering) to the baseline  were used to only block half the beam, creating beams that where neither flat nor symmetric.2.B2.B.1The MPC MLC positioning test uses an image of a static MLC comb‐shaped pattern. The position of each leaf is determined in these images and compared to the intended position. The MLC position is defined as the distance of the MLC tip from the MLCs center line, where the center line is determined as the line through the center of rotation of the MLC, perpendicular to the MLC direction of movement.Similar images are also used to check the collimator angle readout and to find the position of the radiation isocenter relative to the collimator rotation axis. The mean and maximum differences between intended and measured positions for all the leaves in each MLC bank are included in the MPC report.2.B.2To assess the accuracy of the MPC MLC positioning test for the Halcyon system, we intentionally miscalibrated one MLC position by 0.5, 1.0, 1.5, 2.0 mm, and 5.25 mm. This was achieved by changing the MLC offset — this is a setting not accesible to users, and required Varian engineering support. The MLC position values reported by MPC were compared with these known miscalibrated values. The accuracy of MPC MLC positioning for the TrueBeam has been well studied by Barnes et al., and was not repeated in this work.2.C2.C.1For the TrueBeam system, the MPC measures the couch travel distance between two points with a threshold of ±0.7 mm for lateral and longitudinal translation and ±1.2 mm in the vertical. For the Halcyon system the threshold is ±0.5 mm in all directions. On the Halcyon, the MPC also assesses the translation of the couch from the virtual isocenter outside the bore to the treatment isocenter with a threshold of ±2.0 mm — this large threshold is reasonable as the outer lasers are only used for a rough setup and the manufacturer has required that all patients treated on the machine will get daily IGRT for the final setup. The couch shifts (for shifts inside the bore) are measured based on the fiducials visible in the images. The translation of the couch from the virtual isocenter outside the bore to the treatment isocenter starts at a fixed couch coordinate for which, if the couch coordinates are consistent, the MPC phantom should be aligned with the external lasers. The MPC does not explicitly check this, and the user would have to intervene if this was not the case. The couch is then moved into the bore and the couch positioning at the isocenter is confirmed using images of the phantom.2.C.2A stepper motor controlled linear stage  was used to shift the MPC phantom during the MPC couch translation tests [Figs. The movement of the couch to the actual isocenter was evaluated in the same way, except that no images were taken with the phantom at the first position , so the phantom was shifted prior to initiating the MPC sequence.2.D2.D.1The MPC measurement of the absolute gantry position is based on the coincidence of the couch's vertical axis with the central beam axis when the gantry is at 0°. That is, 0° is taken as the situation when a movement along the vertical couch axis does not give any lateral or longitudinal shift of the phantom. The relative gantry test evaluates the accuracy of gantry rotation, using MV images of the MPC phantom at eight gantry angles (45° apart), not compared with the nominal gantry angle. The TrueBeam MPC reports the maximum offset between the angle determined, using the MV imaging system and the nominal gantry angle.2.D.2The MPC test of the absolute gantry position was evaluated for Halcyon linac. We intentionally miscalibrated the gantry position by 0.3°, 0.5°, 1.0°, and 2.0°, all in the same direction, with the actual rotation measured using a digital level. The values reported by MPC were compared to these expected values.The MPC test for the relative gantry rotation was assessed by removing the phantom mounting bracket and then mounting the MPC phantom on a stepper motor controlled rotational stage (Velmex Inc.) [Fig. 3The results of the error detection tests are summarized in Table To evaluate the reproducibility of the MPC tests, the process was repeated three times, and the range in the reported values calculated. The ranges were 0.44% and 0.15% for the reported changes in output and uniformity, respectively, 0.04° for gantry measurements, and 0.05 mm for couch shifts in any direction.3.AWe compared the change in beam output reported by the MPC and the output change measured by the IC Profiler. For both the TrueBeam and Halcyon linacs, the MPC tended to overreport the change in linac output compared with the IC Profiler. This difference increased with larger changes in beam output, and was <2% for clinically realistic changes of <5%. This overreporting results in a conservative QA results, and is consistent with use for daily QA. . Changes in the Halcyon symmetry were measured by the IC profiler, and plotted against the uniformity measured by the Halcyon and TrueBeam MPC Fig. . For Tru3.BThe differences between the MLC offset measured by MPC and the intentionally miscalibrated values are listed in Table 3.CIn order to assess any impact of the translational stages on the experimental setup, MPC was performed with the phantom attached to the stage, but without any induced shifts. The results were within the ranges found when MPC was repeated multiple times (reported above), indicating that the presence of the translational stage itself does not impact the MPC results.The difference between the phantom offset shifted by the linear translation motor and the MPC measurement for both TrueBeam and Halcyon linacs is shown in Table 3.DThe differences between the absolute gantry angle measured by the Halcyon MPC and the known miscalibrated values are also listed in Table The detailed measurement results of the MPC relative gantry rotation tests for both TrueBeam and Halcyon linacs are listed in Table 4Our testing has shown that the Machine Performance Check, as deployed with the Halcyon and TrueBeam treatment device, is capable of detecting changes/errors in beam constancy and mechanical parameters to a level that is appropriate for use for daily QA.4.AThese results indicate that the MPC can detect changes in beam output and uniformity with sufficient accuracy/precision for daily QA. One important weakness in our study is in the way in which we changed the beam output. We inserted solid water into the beam, which has the additional impact of hardening the radiation beam — thus, the changes detected by the MPC test are likely and also partially due to the overresponse of the portal imager to the low energy component of the beam, resulting in larger differences than may be found without this effect. Barnes and Greer tested the ability of the MPC to accurately detect output by intentionally adjusting the linac output (TrueBeam) and found that MPC output agreed with ion chamber to within 0.17%,Our approach was to try to change the output  using external means. Thus, when both results are considered together , this adds confidence to our conclusion that the MPC can detect changes in beam output and uniformity. Furthermore, although we did not report on the day‐to‐day stability of these measurements, other authors4.BThe accuracy of the MPC MLC position test was well within the 1–2 mm tolerance suggested by TG142 for daily checks of the collimator size indicator , indicating that the MPC is sufficient for daily QA. The MPC does not explicitly include some of the more detailed MLC tests suggested for less frequent checks . It should be reasonably simple for the vendor to add some of these tests to a future version of the MPC. It should be noted that the MLC version available in our preclinical Halcyon is an early version, where the upper MLC bank is slaved to the lower bank. Additional tests will be necessary when the vendor releases a version where the upper and lower banks operate independently.4.CThe largest disagreement between the couch translation (or absolute position) and the intentionally inserted error was less than 0.5 mm, well within the 1 to 2 mm tolerances suggested in TG‐179 for couch shift accuracy . These results support the use of the MPC for checking these parameters. Although we do not yet have any data on the expected failure modes of the gantry rotation , given that the tolerance for gantry angle indicators suggested by the AAPM TG 142 is 1.0°, the results presented here indicate that (with the current vendor threshold), the use of the MPC is appropriate for testing gantry angle errors. These results, therefore, support the use of the MPC checks to replace some of the mechanical checks that are often performed on a daily basis. They may also replace some of the mechanical checks that are performed monthly.There are some limitations of our study. We did not perform any tests of the coincidence of imaging and treatment isocenters. Our early version of the Halcyon did not include kilovoltage imaging, so this will have to be tested once released. Our version of the MLC was also a preclinical version . Our MLC tests were also limited to changing the calibration for a single MLC leaf, although this limitation is somewhat mitigated because earlier authors have investigated this issue (Barnes). Finally, we did not assess changes in the MPC over time. We do not expect this to be a concern for mechanical tests, and other authors have followed the MPC output results over relatively extended periods.In summary, our tests have shown that the MPC can detect errors in the beam constancy and geometric parameters with an accuracy that is appropriate for use as daily QA. In many cases, the MPC also has the potential to replace monthly QA checks, but additional work  is needed before a solid conclusion can be given regarding the use of MPC for monthly QA.5We showed that the MPC of both Halcyon and TrueBeam linacs can detect errors in the beam constancy and geometric parameters with an accuracy that means the MPC is appropriate for use as daily QA.


The authors wish to make the following correction to their paper :Molecules as part of the Special Issue entitled “Natural Products in Prevention and Treatment of Metabolic Syndrome”. The correct order should be: Figure 4a is supposed to be Figure 4b and Figure 4b is supposed to be Figure 4a. The captions will match after changing the images. Thus, the originally published figures, shown below:would be replaced with the following figures, now in the correct order:We have found the following error in Figure 4a and Figure 4b of this article, which was recently published in The authors would like to apologize for any inconvenience caused to the readers by these changes.