Emergency departments (ED) globally are addressing the coronavirus disease 2019 (COVID-19) pandemic with varying degrees of success. We leveraged the 17-country, Emergency Medicine Education & Research by Global Experts (EMERGE) network and non-EMERGE ED contacts to understand ED emergency preparedness and practices globally when combating the COVID-19 pandemic.We electronically surveyed EMERGE and non-EMERGE EDs from April 3–June 1, 2020 on ED capacity, pandemic preparedness plans, triage methods, staffing, supplies, and communication practices. The survey was available in English, Mandarin Chinese, and Spanish to optimize participation. We analyzed survey responses using descriptive statistics.74/129 (57%) EDs from 28 countries in all six World Health Organization global regions responded. Most EDs were in Asia (49%), followed by North America (28%), and Europe (14%). Nearly all EDs (97%) developed and implemented protocols for screening, testing, and treating patients with suspected COVID-19 infections. Sixty percent responded that provider staffing/back-up plans were ineffective. Many sites  reported staff missing work due to possible illness with the highest provider proportion of COVID-19 exposures and infections among nurses.Despite having disaster plans in place, ED pandemic preparedness and response continue to be a challenge. Global emergency research networks are vital for generating and disseminating large-scale event data, which is particularly important during a pandemic. Emergency departments (ED) globally are on the front lines in addressing the COVID-19 pandemic, caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Most EDs have disaster preparedness plans in place for health system responses to large-scale disasters, including infectious disease outbreaks. However, infectious disease pandemics pose a unique challenge due to their infrequency and the extended period over which they may occur.The incomplete and evolving knowledge of a novel pathogen limits early preparations for resource needs during a pandemic and predisposes individuals and communities to poor health outcomes. Critical evaluation of the global response to the 2009 H1N1 influenza pandemic identified substantial variability and poorly conceived or even absent preparedness plans in many emergency care systems.Emergency medicine networks are valuable for collection of data supporting research, administrative, and educational goals and can potentially be leveraged to collate and disseminate experiences from disasters.6In this study we sought to leverage the EMERGE network and establish collaborations with non-EMERGE EDs to determine global ED preparedness for COVID-19 and, specifically, to identify successful processes and protocols that may be adopted and/or adapted by other EDs to improve patient outcomes.We performed a cross-sectional study of ED practices during the pandemic using a survey sent to all participating sites. We reported our results using elements from the Strengthening the Reporting of Observational Studies in Epidemiology; Survey Reporting Guidelines; and the Checklist for Reporting Results of Internet E-Surveys guidelines.What do we already know about this issue?Emergency departments (EDs) globally are on the front lines in addressing the coronavirus disease 2019 pandemic. However, preparedness and effectiveness of responses remain unknown.What was the research question?We leveraged the 17-country, Emergency Medicine Education and Research by Global Experts (EMERGE) network and non-EMERGE EDs to study emergency preparedness globally.What was the major finding of the study?EDs had to rapidly update and modify preparedness plans. EDs developed innovative processes to respond, and most identified provider burnout as an important issue.How does this improve population health?Emergency research networks are vital for generating and disseminating solutions to improve patient outcomes in global emergencies.Survey participation was voluntary, and respondents did not receive financial remuneration. The survey was distributed to EMERGE member institutions via email with unique links created for each participant. Attempts were made to involve non-EMERGE institutions by forwarding a one-page infographic  to contaWe tabulated descriptive statistics including absolute and relative frequencies for categorical variables and means (with standard deviations [SD]) or medians (with interquartile ranges [IQR]) for continuous variables, depending on normality, to compare all survey question responses. We defined ED characteristics by location, setting, and size. We grouped EDs by location into geographical categories: Asia; Europe; North America; South America; Africa; and Australia. Hospital setting was defined along two domains. First, we defined them as “public” or “government-funded” hospitals with the rest defined as “private” hospitals. Second, we categorized hospitals as “academic” vs “non-academic” based on presence of residency training programs. We used SAS 9.4  for all quantitative analyses. ED characteristics stratified by country, continent, and income status (gross domestic product) as well as COVID-19 prevalence and death rates at time of survey completion are provided in We identified 129 EDs across 28 countries within all six World Health Organization (WHO) regions. Of these, 74 (57%) completed the survey, comprising 23/26 (88%) EMERGE EDs and 51/103 (49%) non-EMERGE EDs . There wMost sites  reported having an ED protocol to guide the screening, testing, and managing of suspected COVID-19 cases, and 27 (36%) sites sent their protocols for other EDs across the globe to use. There were 43/74 EDs (58%) that had ED staffing back-up plans prior to the COVID-19 outbreak. Regarding supply availability, 59/71 (83%) reported stocking the ED with personal protective equipment (PPE) as a part of pre-existing disaster plans. However, when respondents answered questions regarding effectiveness of existing disaster plans only 59/74 (80%) replied. Of these, 48/59 (81%) responded that the plan was successful/effective. Regarding personnel and ED staffing back-up plans, 26 felt they were very effective, 33 somewhat effective, six not effective, and nine did not respond. Reasons for disaster plans being successful or not are described in Nearly every ED  developed and implemented a protocol for screening, testing, and managing patients with suspected SARS-CoV-2 infections. The WHO recommendations for COVID-19 informed the pandemic response plans for 28/73 (38%) EDs in our sample. Outside the United States, 13/59 (22%) EDs based their pandemic response plans on the US Centers for Disease Control and Prevention (CDC) guidelines. The majority  based their plans on guidelines issued by their own countries.Screening criteria for COVID-19 were generally similar across the EDs in our survey, with less similarity across survey respondents in approaches for increasing treatment capacity. Screening criteria used are provided in Many survey respondents identified staffing issues as a particularly challenging aspect of the COVID-19 pandemic response. Most respondents  developed new or separate staff backup plans specifically for COVID-19 while 22/74 EDs (30%) had activated their existing staff backup plans at the time the survey was completed. From the received responses 47/74 (64%) reported staff missing work due to illness, and 32/74 (43%) reported that ED provider staff had tested positive for SARS-CoV-2. Inability to work due to possible COVID-19 illness was reported in nurses in 26/32 (81%) responses, followed by physicians, 21/32 (66%), and residents, 20/32 (63%). Common measures to address staff wellness and prevent burnout included allowing staff to work remotely  and providing meals at work . If staff had a confirmed positive SARS-CoV-2 test, criteria for returning to work included a negative test  and/or being symptom-free for a site-determined duration of days .On a multiple-option question, 55/74 (74%) respondents selected that they were able to test for SARS-CoV-2 in their EDs, 23/74 (31%) selected that samples were sent to an external agency for testing, and 4/74 (5%) sites indicated that they did not perform any testing.Most EDs were able to provide face masks for patients with suspected COVID-19 or influenza-like illness at arrival . Supplies in EDs that were most likely to be depleted (defined as a <14-day supply) at the time of the survey included powered air purifying respirator systems  and N-95 masks .Survey respondents exhibited wide variation regarding where they obtained information about the evolving pandemic and how they communicated with patients and local communities. The most common sources of information for EDs included local governments/health departments , hospital infection control practitioners , state governments , and the WHO . Common methods for communicating with the local community included social media , television , and newspapers . The most common methods for communicating updates to staff were email , website/intranet , and video conference . The most common methods for communicating updates to patients and families were flyers/posters , in-hospital TV channels/displays , and social media .In an open-ended survey section, we recorded both successful and unsuccessful innovations developed in respondent EDs to address the pandemic . SuccessIn this global survey, we leveraged the EMERGE network to establish rapid collaborations with non-EMERGE EDs and obtained estimates of ED pandemic preparedness and response to COVID-19 from 74 EDs in 28 countries comprising the six WHO regions. Despite substantial differences among surveyed EDs, there were many similarities in how EDs are responding to the pandemic, especially with screening protocols, capacity expansion, and staffing. Despite having disaster plans in place, globally ED pandemic preparedness and response is difficult and variable. There was a substantial human cost to the pandemic as 43% of the EDs reported providers and staff had contracted COVID-19 and missed work, further impacting the ED’s ability to provide care. Finally, EDs were willing to share protocols, lessons learned, and innovative solutions that can be rapidly disseminated via research networks such as EMERGE, or via global organizations such as the WHO to benefit emergency care globally.Our survey identified multiple, latent patient-safety threats due to inadequate disaster preparedness. One third of respondents did not have a pandemic preparedness plan prior to the COVID-19 pandemic. These findings are consistent with another report surveying 102 pediatric EDs in Europe early in the COVID-19 pandemic, which revealed that nearly a third of EDs lacked a contingency plan for pandemics and never had simulated scenarios for such events.Reassuringly, most EDs recognized the impact of the pandemic on staff wellness and had developed plans for improving provider well-being. These interventions included new guidelines for remote work whenever possible, meals during shifts, childcare support, and/or additional time away from work. Disaster management experts voice the importance of frontline workers’ protection through planning, availability of PPE, and mindful staff scheduling, as well as strongly encouraging mental health and peer support with wellness initiatives. Our findings highlight the need for a more cohesive and comprehensive evaluation of existing disaster plans. Lessons learned from our survey could potentially be used to develop multidisciplinary in situ simulations to find optimal solutions for adapting to COVID-19 and other highly complex and evolving epidemics/pandemics in the future.20Nearly all EDs developed site-specific protocols for screening and triage during the pandemic. These protocols included provision of masks and separating patients on arrival to the waiting room. Triage and pre-ED arrival screening involved tele-triage, phone, and video screening, the use of alternative sites , and use of other non-ED sites (such as outpatient clinics and community centers). One site reported a separate screening facility with app-based screening prior to patient registration. Leveraging technology can reduce ED demand and enhance patient understanding of COVID-19 risks and has been used extensively for screening and contact tracing tools, such as the CDC Self-Checker and Singapore’s TraceTogether.The ED and emergency medical services are an integral component of community-based health systems that require strengthening to respond to pandemics; however, it is imperative that we first obtain high quality, global data in a timely manner to understand the impact and subsequent responses. This was the motivation for our survey, which revealed important insights on the state of global pandemic/disaster preparedness. First, apart from regional EM organizations gathering local data, currently there is no infrastructure for assessing the state of ED systems across the globe and sharing experiences to provide rapid, reliable, and actionable data. For instance, adaptation of shared protocols and data would substantially reduce the time to implementation of interventions, underscoring the importance of ED-based research networks. Our survey was initiated in the nascent EMERGE network and we immediately recognized that despite having a “global” footprint, EMERGE is still not representative of the global ED system. It was very reassuring that we were quickly able to reach out to several non-EMERGE EDs via referral, allowing us to expand the survey participant pool from 26 EMERGE EDs in 17 countries to include an additional 51 non-EMERGE EDs from 11 countries. Second, our higher-than-average 57% response rate highlights the willingness of healthcare institutions across the world to participate and share experiences for the global benefit.23Third, the diversity of comments regarding innovations in the domains of triage, testing, communication, staffing, and capacity-building provided in Data obtained from surveys is inherently susceptible to selection and reporting bias. Furthermore, survey participation and response rates have declined over time due to limitations of the study design and inconvenience associated with completing poorly designed or frequent requests. This may be especially true during this pandemic, when multiple and often simultaneous requests for information were circulating broadly and a massive increase in scientific literature submissions related to COVID-19 were published.Given the extremely dynamic nature of the COVID-19 pandemic and the fact that countries were experiencing different levels of disease burden and different phases of the outbreak, the survey results represent the situation at a single point in time for the responding institutions. Thus, responses to survey questions will likely be different if we were to conduct the survey at another point in time. For instance, responses regarding availability of PPE or effectiveness of preparedness plans may differ as institutions continue to respond and adapt in real time. Ultimately, this study is hypothesis-generating and intends to demonstrate the power of our network.Our study cohort represents a large cross-sectional sample of ED responses to an ongoing global healthcare crisis. Despite having disaster plans in place, ED pandemic preparedness and response continue to be a challenge and there were multiple, latent safety threats to providers and patients. We believe global emergency research networks play an important role in near real-time collection of high-quality data on the epidemiology of large-scale events and can disseminate experiences and solutions that will impact healthcare outcomes for individuals, communities, and even nations.


Coronavirus disease 2019 (COVID-19) is an ongoing pandemic and there is an urgent need for safe and effective drugs for COVID-19 treatment. Since developing a new drug is time consuming, many approved or investigational drugs have been repurposed for COVID-19 treatment in clinical trials. Therefore, selection of safe drugs for COVID-19 patients is vital for combating this pandemic. Our goal was to evaluate the safety concerns of drugs by analyzing adverse events reported in post-market surveillance. We collected 296 drugs that have been evaluated in clinical trials for COVID-19 and identified 28,597,464 associated adverse events at the system organ classes (SOCs) level in the FDA adverse events report systems (FAERS). We calculated Z-scores of SOCs that statistically quantify the relative frequency of adverse events of drugs in FAERS to quantitatively measure safety concerns for the drugs. Analyzing the Z-scores revealed that these drugs are associated with different significantly frequent adverse events. Our results suggest that this safety concern metric may serve as a tool to inform selection of drugs with favorable safety profiles for COVID-19 patients in clinical practices. Caution is advised when administering drugs with high Z-scores to patients who are vulnerable to associated adverse events. The World Health Organization (WHO) declared COVID-19 a pandemic on March 11, 2020. As of June 3, 2021, the outbreak has been reported in 213 countries with over 171 million confirmed cases and over 3.68 million deaths. The global spread of the virus has overwhelmed healthcare systems and caused unprecedented disruption to society as well as the economy. The severity of this pandemic demands safe and effective therapeutic approaches. Currently, only one drug, remdesivir under the brand name Veklury, is approved by the U.S. Food and Drug Administration (FDA) for adults and pediatric patients (12 years of age and older and weighing at least 40 kg) for the treatment of COVID-19 requiring hospitalization. Since developing a new drug usually takes more than a decade, many COVID-19 studies use an alternative strategy by repurposing approved or investigational drugs to treat COVID-194. Since approved drugs may have been on the market for years or even decades, their safety, toxicity, and pharmacokinetics are known. This knowledge can be used to shorten the time required for developing these drugs to treat COVID-19.Coronavirus disease 2019 (COVID-19), a newly emerged disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has been rapidly spreading worldwide due to its contagious nature8. As of June 3, 2021, 5849 COVID-19-related clinical trials had been registered with ClinicalTrials.gov and 29% (1693) involved the use of marketed drugs. The efficacy and safety of these drugs for treatment of COVID-19-related indications are being tested in ongoing clinical trials. Among these drugs, the antimalarial drugs hydroxychloroquine and chloroquine are widely used in clinical trials. Based on their potential efficacy10, the FDA and European Medicines Agency (EMA) issued authorization for emergency use of oral formulations of hydroxychloroquine sulfate and chloroquine phosphate in the treatment of COVID-19 patients in late March and early April 2020, respectively. However, on June 15, 2020, the FDA revoked the emergency use authorization (EUA) because these drugs may not be effective in treating COVD-19 and the drugs’ potential benefits for such use do not outweigh their known and potential risks12. Some drugs emerged in the virtual screening as potential COVID-19 drugs, such as dipyridamole13 which inhibits the SARS-CoV-2 main protease, peptides drugs14 and chronic disease drugs15 including candesartan, losartan, telmisartan. Using the chronic disease drugs as an example, these drugs are in the class of angiotensin II receptor blockers (ARBs) and have shown promising affinities against the COVID-19 main protease in molecular docking and molecular dynamics15. Since some clinical trials are still ongoing, the efficacy of those drugs is inconclusive or pending. Therefore, it is important for physicians to select drugs with favorable safety profiles.A remarkable number of drugs have been considered for treating COVID-19 patients18. In our study, we defined a quantitative safety concern measurement for potential COVID-19 drugs using occurrences of adverse events extracted from FAERS. In brief, we first gathered drugs that have been used to treat COVID-19 in clinical trials and are registered in ClinicalTrials.gov. Then, the adverse events reported for these drugs were retrieved from the FAERS database and were mapped to 27 medical dictionary for regulatory activities (MedDRA) system organ classes (SOCs). We calculated a Z-score for each SOC as a qualitative measure of safety concern to indicate a statistically relative frequency of adverse events in the SOC. This safety concern measurement may help physicians select drugs for treating COVID-19 which are tailored to a patient’s clinical features.Although the efficacy of many drugs in treating COVID-19 patients remains unclear, adverse events reported in post-marketing surveillance can be used as a safety measurement to provide physicians information regarding which adverse events are more likely to occur in patients. This knowledge could be further used to inform selection of drugs for treating COVID-19 patients once drugs are approved/authorized for treatment of specified indications. The FDA adverse events reporting system (FAERS) is a self-reporting adverse events system that is widely used to study the relationship between drugs and adverse events due to the large numbers of adverse event reports in the database19 produced 1075 trials for 406 approved or investigational drugs. The remaining 451 clinical trials without approved or investigational drugs were associated with agents not covered in DrugBank, such as traditional Chinese medicines. These 451 trials were excluded. Detailed information on the clinical trials for the 406 drugs are provided in Supplementary Table To investigate the safety of drugs repurposed for COVID-19, we searched ClinicalTrials.gov on June 3, 2021 and found 5849 clinical trials for COVID-19. To focus on promising COVID-19 drugs, we excluded clinical trials that were marked as withdrawn, suspended, and terminated in the recruitment status and 5599 clinical trials remained. Among these 5599 clinical trials, 1526 were listed as intervention with drugs. Searching the 1526 clinical trials by common drug names and synonyms from the DrugBank database12. The antiparasitic drug, ivermectin, has also been intensively studied for COVID-19 treatment, especially when combined with hydroxychloroquine20. Other intensively studied drugs include remdesivir with 50 clinical trials, azithromycin with 48 clinical trials, tocilizumab with 47 clinical trials, favipiravir with 33 clinical trials, ritonavir with 33 clinical trials, lopinavir with 31 clinical trials and heparin with 30 clinical trials.Hydroxychloroquine and ivermectin have been utilized in 119 and 63 clinical trials, respectively. It is not surprising that hydroxychloroquine has been extensively studied because it was initially reported to have some inhibitory activity against SARS-CoV-221. These two drugs have been used as an emergency treatment for COVID-19 patients in many countries including the U.S., Singapore and Japan7. However, recent studies have not shown clinical benefit of this combination of drugs for COVID-1922.To examine the preferred type of drugs repurposed for COVID-19 treatment, drugs were grouped using the anatomical therapeutic chemical (ATC) classification system. We grouped 237 drugs out of 406 into 14 main pharmacological groups using their first level ATC codes  and “musculoskeletal and connective tissue disorders” (Z-score = 2.5), strongly suggesting that physicians need to consider these adverse events in benefit risk assessment before prescribing this drug to COVID-19 patients whose clinical information shows vulnerability to such adverse events. Rosenberg et al.23 conducted a retrospective multicenter cohort study of patients with COVID-19 treated with both hydroxychloroquine and azithromycin, hydroxychloroquine alone, azithromycin alone, or neither and found that cardiac arrest was more likely in patients who received both hydroxychloroquine and azithromycin, but not hydroxychloroquine alone and azithromycin alone, compared with patients who received neither drug, even after adjustment. Their findings are consistent with our results that cardiac disorder is a less frequently reported adverse event for hydroxychloroquine alone (Z-score =  − 0.4) and azithromycin alone (Z-score =  − 0.03). Thus, our Z-scores could be used to as a safety concern metric for drugs for treating COVID19 patients. Another example is chloroquine which is being tested in 12 clinical trials for COVID-19 treatment. Our safety analysis revealed that this drug frequently causes adverse events pertaining to cardiac disorders (Z-score = 2.4). Therefore, it is recommended that physicians avoid prescribing chloroquine to patients vulnerable to these types of adverse events, such as patients with hypertension.To quantitatively measure the relative frequency of adverse events as drug safety metrics, we calculated Z-scores of adverse events in SOCs for each drug. A higher Z-score for a drug indicates a greater likelihood of the occurrence of SOC adverse events. Z-scores on the 27 SOCs for the 296 drugs for COVID-19 treatment in clinical trials are shown in Supplementary Table Our safety concern metrics can be used for guidance in avoiding improper prescription of drugs to patients, and can also help to optimize treatment for COVID-19. For example, in patients with hypertension, our results  that could impact results; some drugs may show significant sex/race difference in adverse events. Third, we did not have access to the efficacy side of the equation for drug selection. If the health benefit of a drug outweighs its safety concern, drugs with severe toxicity and/or high Z-score may still be used in clinical practice. Fourth, dose was not included in our study because we had difficulties obtaining dose information from clinical trials. Furthermore, because the majority of the COVID-19 trials are still ongoing, our safety metrics did not include safety information from COVID-19 patients in these trials. Lastly, we did not consider the severity of the adverse events which is an important clinical consideration.https://www.covid19treatmentguidelines.nih.gov/whats-new/). Physicians should be cognizant of the Z-scores as the treatment algorithms evolve.In summary, we investigated safety concerns for COVID-19 drugs by analyzing adverse events reported in FAERS. We found 406 drugs registered in ClinicalTrials.gov, of which 296 drugs showed 28,597,464 SOCs adverse events in FAERS. We calculated Z-scores for SOCs of adverse events to qualitatively measure safety concerns for 296 drugs. Physicians may need to be cautious when prescribing drugs with high Z-scores for adverse events in SOCs in which patients have vulnerabilities. New evidence is evolving every day on clinical outcomes and different treatment options for patients infected with SARS-CoV-2. Since our original analyses, additional options have become available for the management of COVID-19  codes. The ATC classification system divides drugs into different groups according to the organ or system on which they act. There are five levels in the ATC classification system. The first level has 14 codes corresponding to 14 anatomical main groups. ATC codes for drugs were extracted from the National Center for Biomedical Ontology (NCBO) BioPortal ontologiesFAERS is a self-reporting adverse events system provided by the FDA. It is widely used to study relationships between drugs and adverse events due to the large number of adverse event reports in the database. To investigate the potential link between COVID-19 drugs and adverse events, we downloaded the publicly available FAERS database from January 2004 to March 2021. Since FAERS is a self-reporting system, it contains duplicate and incomplete reports. To improve the data quality, we pre-processed duplicate and incomplete reports in our analysis. Only the latest version of the report was retained for duplicate reports with the same case ID, drug name, and adverse events. The incomplete reports were also removed if we could not locate the report case ID, drug name and its adverse events. To reduce the risk of false positives, only “primary suspected” and “secondary suspected” drugs for the reported adverse event were considered in our analysis. After cleaning up the database, we used the drugs names extracted from clinical trials to find their adverse events. Since the drug names in FAERS are not standardized, and may be full names, trade names or abbreviations, we used the active ingredients, commonly used drug name, and synonyms of the extracted drugs to do a thorough search. The synonym and commonly used drug names were taken from DrugBank. Finally, we identified 28,597,464 adverse events reported for the drugs that were used in the clinical trials registered on ClinicalTrials.gov.26. We used MedDRA V22.1 to group the reported LLTs and PTs into 27 SOCs. The adverse events that were not identified as PTs or LLTs in MedDRA V22.1 were discarded in our analysis. SOCs are the highest level of MedDRA hierarchy. LLT and PTs are grouped into SOCs by their physiological system, manifestation site or purpose. Since one PT may be mapped to different SOCs, only the primary SOC was considered in the analysis. The 27 SOCs and their abbreviations used in this study are listed in Supplementary Table The adverse events in the FAERS database are reported using preferred terms (PTs) or lowest level terms (LLTs) in MedDRAi that were found in FAERS for drug j, j and is calculated by dividing the total number of adverse events by 27 (number of SOCs), and j. If the Z-score for a SOC for a specific drug is larger than 2, this SOC is a significantly frequent adverse event among all 27 SOCs. Similarly, this SOC is a frequent adverse event if its Z-score is between 1 and 2, and a slightly frequent adverse event if Z-score is between 0 and 1; likely infrequent adverse event if Z-score is between -1 and 0 and an infrequent adverse event if Z-score is less than − 1.To examine whether the occurrence of an SOC of adverse events was significantly frequent for a drug, we calculated the Z-score for the SOC and the drug using the following equation.http://python.org) .All data processing and statistical analyses were performed using in-house Python scripts in Python 3.6 (Python Software Foundation, Supplementary Information 1.Supplementary Information 2.Supplementary Information 3.Supplementary Information 4.


Oncolytic viruses are a new class of therapeutics which are largely in the experimental stage, with just one virus approved by the FDA thus far. While the concept of oncolytic virotherapy is not new, advancements in the fields of molecular biology and virology have renewed the interest in using viruses as oncolytic agents. Backed by robust preclinical data, many oncolytic viruses have entered clinical trials. Oncolytic viruses that have completed some levels of clinical trials or are currently undergoing clinical trials are mostly genetically engineered viruses, with the exception of some RNA viruses. Reolysin, an unmodified RNA virus is clinically the most advanced oncolytic RNA virus that has completed different phases of clinical trials. Other oncolytic viruses that have been studied in clinical trials are mostly DNA viruses that belong to one of the three families: herpesviridae, poxviridae or adenoviridae. In this review work we discuss recent clinical studies with oncolytic viruses, especially herpesvirus, poxvirus, adenovirus and reovirus. In summary, the oncolytic viruses tested so far are well tolerated, even in immune-suppressed patients. For most oncolytic viruses, mild and acceptable toxicities are seen at the currently defined highest feasible doses. However, anti-tumor efficacies of oncolytic viruses have been modest, especially when used as monotherapy. Therefore, the potency of oncolytic viruses needs to be enhanced for more oncolytic viruses to hit the clinic. Aiming to achieve higher therapeutic benefits, oncolytic viruses are currently being studied in combination with other therapies. Here we discuss the currently available clinical data on oncolytic viruses, either as monotherapy or in combination with other treatments. There has been an increasing interest in using viruses as potential therapeutics for different types of diseases. Two main ways in which viruses are being explored as therapeutics are (1) vectors for gene therapy and (2) oncolytic viruses. While viruses as vector for gene therapy are being studied for a wide range of diseases including cancer, “oncolytic viruses” are specific for cancer treatment. The major difference between viral vector for gene therapy and oncolytic virus is that viral vectors used in gene therapy are non-replicating viruses, whereas oncolytic viruses are replication-competent viruses. Oncolytic viruses (OV) are wild-type or engineered viruses that can selectively replicate in and kill cancer cells while leaving normal cells unharmed. OVs are a novel class of multi-mechanistic therapeutics for the treatment of cancer. Some of the mechanisms through which OVs exert their anti-cancer effect include direct lysis of cancer cells and activation of anti-tumor immunity .The concept of using viruses to kill cancer is not new, there is anecdotal evidence of anti-tumor benefits from virus infections dating back to a century ago . HoweICP34.5 [Herpes simplex virus-1 (HSV-1) belongs to the family herpesviridae. It is an enveloped, double-stranded DNA virus with genome size of approximately 150 kbp that encodes ~89 genes . Many HSICP34.5). Furthermore, immunostimulatory properties of T-VEC have been improved by the deletion of the gene ICP47, an inhibitor of major histocompatibility complex I (MHC-I) mediated antigen presentation, and by the insertion of granulocyte-macrophage colony-stimulating factor (GM-CSF) expression cassettes at both loci of ICP34.5. The deletion of ICP47 enhances immune-mediated destruction of the virus-infected cells, whereas virus-encoded GM-CSF increases recruitment and activities of dendritic cells, ultimately boosting anti-tumor immunity [Talimogene laherparepvec (T-VEC) marketed as Imlygic, is a JS-1 strain of HSV-1 that was originally isolated from a cold sore ,7. The v6 plaque forming units (PFUs) of virus followed by multiple injections of higher doses (107 or 108 PFUs). The treatment was well tolerated with the most common side effects being local inflammation and erythema febrile responses. Overall responses to the treatment were mild; however, it was encouraging to find that the virus was able to replicate in the tumors, produce GM-CSF, cause tumor necrosis and inflammation in both the injected and, in some cases, un-injected tumors. After this Phase I study, an initial Phase II clinical trial was performed that included 50 patients with stage IIIC unresectable or metastatic melanoma [8 PFU at the interval of 2 weeks for up to 24 treatments. Tumor regression was observed not only in the injected lesions, but also in un-injected distant tumors including visceral metastases. The overall response rate (ORR) was 26% with 8 out of 13 responding patients experiencing a complete response. The treatment was well tolerated with the most common side-effects being inflammation at injection sites, flu-like symptoms and nausea. This encouraging Phase II trial was followed by a Phase III trial, which involved 436 patients with stage IIIB to IV melanoma. In this study, efficacy of intratumoral T-VEC treatment was compared with a subcutaneous injection of GM-CSF [In preclinical studies, T-VEC was found to induce strong cytotoxic activities against a wide range of tumor cell lines in vitro and caused tumor regression in murine models ,9. Follomelanoma . T-VEC wf GM-CSF . The ORRClinicaltrials.gov; accessed on 1 March 2021) to determine safety and efficacy of T-VEC either as monotherapy or in combination with other therapeutics, including immune checkpoint inhibitors, in different types of cancers. Some of these studies, which are currently in trials, are mentioned in Puzanov et al. reported the findings of a Phase Ib trial of T-VEC in combination with ipilimumab (a cytotoxic T-lymphocyte-associated antigen 4 (CTLA4) checkpoint inhibitor) in patients with advanced melanoma . The comICP34.5 genes. Additionally, G207 has the ICP6 gene inactivated through the insertion of the Escherichia coli lacZ gene. The ICP6 gene encodes a viral homolog of the cellular protein ribonucleotide reductase (RR), an enzyme required for the production of deoxy-ribonucleotides (dNTPs) [ICP6 restricts virus replication to dividing cells with high levels of RR such as cancer cells. While this virus was originally designed for treatment of brain tumors, preclinical studies have found that the virus is effective against a wide range of cancer types including prostate, breast, head and neck, colon, ovaries, neuroblastoma, osteosarcoma and melanoma [6 to 3 × 109 PFUs of the virus intratumorally. Some patients experienced adverse events, but toxicities were not directly related to the virus. Radiographic and neuropathologic analysis showed some evidence of anti-tumor activity. In another Phase I study, nine patients with recurrent malignant glioma were treated intratumorally with 109 PFUs of G207 followed by treatment with 5 Gy radiation [G207 is another oncolytic HSV-1 that has completed several Phase I trials and is expected to begin a Phase II trial soon. Similar to T-VEC, G207 has deletions in both copies of  (dNTPs) . Deletiomelanoma ,20,21,22melanoma . A totaladiation . This coICP47, which allows for enhanced MHC-I presentation on infected cells [n = 13 patients) was significantly higher (92.3%) than the control group (15%) [G47Δ is a variant of G207 that has also been tested for safety and efficacy in glioblastoma and prostate cancer in Japan. G47Δ has an additional deletion in the gene ed cells . Interimup (15%) . Severe up (15%) .ICP34.5 genes [ICP4, ICP27, UL8), and in ICP34.5, that potently inhibit virus replication in normal cells, but not in cancer cells [UL37 gene that prevent axonal retrograde transport as well as latency, ensuring that virus will not damage neurons. Additionally, ONCR-177 encodes five immune-modulatory transgenes  driven by a dual bi-directional promoter [ONCR-177 is an oncolytic HSV-1 virus developed by Oncorus Inc. Unlike T-VEC and G207, ONCR-177 is not deleted in .5 genes . Target er cells . FurtherRP1 is an oncolytic HSV-1 virus containing deletions in the neurovirulence genes ICP34.5 and ICP47. It has two transgenes inserted in its genome: GM-CSF and gibbon ape leukemia virus glycoprotein (GALV-GP R-), a fusogenic membrane glycoprotein. This virus is currently in Phase I trial as monotherapy for recurrent or advanced cutaneous squamous cell carcinoma (NCT04349436) or in combination with anti-PD-1 antibody (NCT04050436). RP1 has been further modified (known as RP2) to express anti-CTL4, which is also undergoing a Phase I trial (NCT03767348).Vaccinia virus (VACV) is an enveloped virus belonging to the family poxviridae. VACV has a linear double-stranded DNA genome that is approximately 200 kpb in size and encodes ~200 genes . VACV isJ2R, encoding for thymidine kinase, replaced by the expression cassettes for human GM-CSF (hGM-CSF) and lacZ [J2R with the aim of increasing its cancer-specificity, and the hGM-CSF expression cassette was inserted with the aim of increasing anti-tumor immunity through the recruitment and activation of antigen-presenting cells (APCs) and cytotoxic T lymphocytes (CTLs) [9 PFUs of JX-594 intratumorally or intravenously. Compared to the control group, the intratumoral or intravenous injection of JX-594 potently inhibited the growth of primary tumors. Furthermore, while all control-treated rabbits developed lung metastases, none of the rabbits treated with JX-594 developed lung metastases. Interestingly, in the rat model in which human GM-CSF is not compatible, 108 PFUs of JX-594 injected three times (intravenous) at the interval of 2 weeks, resulted in a complete tumor regression in majority of the treated mice. This study by Kim et al. was encouraging, especially because it involved immune-competent orthotopic tumor models, as opposed to other studies, most of which used human xenograft models and intratumoral injections for the evaluation of oncolytic viruses.Pexa-Vec (formerly JX-594) is a Wyeth strain of vaccinia virus that has and lacZ . Pexa-Ves (CTLs) . The cons (CTLs) . In thiss (CTLs) . While bJ2R gene was replaced with expression cassettes for hGM-CSF and β-galactosidase. In this study, a total of seven patients with unresectable melanoma were treated twice weekly with intratumoral injections of escalating doses of the virus for 6 weeks. A maximum dose of 8 × 107 PFU virus was used in the study and no maximum tolerable dose (MTD) was reached. Tumor regression in a fraction of patients was observed in this study, and systemic toxicity was limited to flu-like symptoms that resolved within 24 h. Followed by this pilot study, an open-label Phase I dose-escalation trial was conducted with substantially higher doses with the aim of defining safety and the MTD of JX-594 [8 PFU to 3 × 109 PFU every 3 weeks. Grade 1–3 flu-like symptoms were observed in all patients and 4 out of 14 patients experienced transient grade 1–3 dose-related thrombocytopenia. Furthermore, patients treated with the highest dose (3 × 109 PFU) displayed hyperbilirubinemia, which was considered dose-limiting. From this study, 1 × 109 PFU was determined to be the MTD for JX-594. In addition to finding the MTD, several insights were gained from this Phase I trial. First, the study showed that it is possible for the virus to disseminate from injected to non-injected tumors through blood; virus replication and expression of GM-CSF were also confirmed. Second, tumor responses were observed in both injected and non-injected tumors. In terms of efficacy, out of 10 radiographically evaluable patients, 3 had partial response, 6 had stable disease and 1 had progressive disease.The prototype of JX-594 was used in a pilot Phase I trial in 1998 . The virf JX-594 . This st9 PFU. In this study, virus treatment was found to be safe and anti-tumor efficacy was observed in all patients despite the presence of high levels of neutralizing antibodies. JX-594 was found to replicate in tumors and release of virus in circulation was observed. Additionally, this study showed that the virus treatment elevated the levels of anti-vascular cytokines, resulting in tumor vascular shutdown. Interestingly, JX-594 was also found to suppress the replication of hepatitis B virus in HCC patients. Another pilot study was reported by Heo et al. in 2011 on the combination of JX-594 with the kinase inhibitor, sorafenib, for the treatment of HCC [Liu et al. reported another pilot study of JX-594 in advanced refractory hepatitis B virus (HBV)-associated hepatocellular carcinoma (HCC) . The virt of HCC . In muri9 PFU, which was generally well tolerated. This study included a total of 23 patients. The virus was detectable in tumor biopsies of patients who received virus at the dose ≥109 PFU. This study provided the proof-of-concept regarding the feasibility of the systemic administration of JX-594 for the treatment of tumors.In 2011, Breitbach et al. reported the findings from a Phase I dose-escalation trial of a single intravenous infusion of JX-594 . The max8 PFU (low-dose) and 109 PFU (high-dose) were used for intratumoral infusions on day 1, 15 and 29 in patients with advanced hepatocellular carcinoma. The objective of this study was to compare the safety and efficacy of low- and high-dose treatments and induction of immunity against both cancer cells and the oncolytic virus. The objective response rate (15%) and intrahepatic disease control (50%) were found to be equivalent in the injected and non-injected distant tumors for both the doses. GM-CSF expression and the induction of anti-tumor immunity was observed at both the doses. While the tumor response rate and immune endpoints were similar for the low- and high-dose treatments, survival of patients treated with the high-dose treatment was significantly higher  than that for patients treated with the low-dose treatment (6.7 months).Results from a Phase II dose-finding trial for JX-594 in liver cancer treatment were reported by Heo et al. in 2013 . A total9 PFU) was followed by up to five intratumoral injections. The treatment was generally well tolerated and evidence of immune induction against the virus as well as tumor antigens were observed. However, in this study Pexa-Vec failed to improve the survival of patients; the overall survival of patients treated with BSC alone (4.2 months) was not significantly different from the overall survival of patients treated with BSC plus Pexa-Vec. Currently, Pexa-Vec is being tested in combination with sorafenib in a worldwide Phase III PHOCUS trial in HCC patients.Recently, results from a multicenter Phase IIb trial of Pexa-Vec in sorafenib-resistant hepatocellular carcinoma (TRAVERSE) were published by Moehler et al. . Patient9 PFU. While all these studies have established an excellent safety profile for this virus, the anti-tumor efficacy of the virus remains uncertain.Thus far, more than a dozen clinical trials have been completed with JX-594 (Pexa-Vec) in multiple types of malignancies, in which more that 400 patients have been injected with the virus. The MTD has been determined to be 10J2R gene. Additionally, GL-ONC1 is deleted in the F14.5L and A56R genes. The virus encodes three transgenes: β-galactosidase, β-glucuronidase and Renilla luciferase–Aequorea green fluorescent protein [GL-ONC1 (formerly known as GLV-1h68) is an oncolytic VACV based on the Lister strain developed by Genelux Corporation . Like JX protein . In prec protein ,40,41,42J2R and C11R (vaccinia growth factor) genes, and it encodes bacterial cytosine deaminase as well as the somatostatin receptor [J2R and C11R allows for vvDD to selectively replicate in cells with an active E2F and epidermal growth factor receptor (EGFR/Ras) pathway, common features of many cancer cells [9 PFU of virus, the maximum feasible dose, was injected intratumorally without dose-limiting toxicities. The virus was recovered from both injected and non-injected tumors. Although no clinical benefits were achieved in this study, it was encouraging to see that the WR strain of VACV was well tolerated even at the maximum feasible dose of 3 × 109 PFU.The vvDD  is a Western Reserve (WR) strain of VACV that is deleted in receptor . The WR receptor . Deletioer cells ,44,45. Ter cells ,44,45. Fer cells . In this9 PFU virus was injected in patients. The virus was well tolerated with the most common adverse events being grade 1/2 flu-like symptoms. Tumor-specific replication of the virus was observed. Clinical benefits were minimal, but the authors concluded that excellent safety profile of the virus warrants further trials in combination with other therapeutics such as checkpoint inhibitors. The second clinical study using vvDD was published by Downs-Canner et al. in 2016 . In thisClinicaltrials.gov for the term “oncolytic adenovirus” displayed a total of 45 studies in different phases of trials, out of which 11 have been completed and 14 are currently recruiting patients. An oncolytic adenovirus called H101 , is the first oncolytic virus to be approved for the treatment of cancer. H101 is an E1B-deleted adenovirus type 5 that was approved in China in November 2005 for the treatment of head and neck cancer [Adenoviruses are non-enveloped viruses with linear double-stranded DNA genome that ranges from 26 to 45 kbp in size . A searck cancer . Despiteclinicaltrials.gov (accessed on 1 March 2021), DNX-2401 has completed four Phase I trials in patients with brain tumors/glioblastoma and one Phase I trial in patients with ovarian cancer and primary peritoneal cancer. In brain cancer patients, the virus has been studied as a single agent or in combination with other therapeutics such as interferon-y, temozolomide or pembrolizumab. While results from most of the studies have not been published, in 2019 Philbrick and Adamson published the findings of a Phase I study of DX-2401 in patients with recurrent high-grade gliomas [DNX-2401  is an oncolytic adenovirus in which the early gene E1A is inactivated through the deletion of 24 bp in the E1A gene . E1A ina gliomas . In this13 virus particles were administered through intravenous infusion. The most common adverse events of grade 3 were hypoxia, lymphopenia and neutropenia, which were manageable [Kuhn et al. used recombination and a directed evolution approach to create a chimeric group B oncolytic adenovirus called Enadenotucirev . This vinageable . There aLOAd703 is another oncolytic adenovirus that has shown promising results in preclinical studies and is actively being tested in clinical studies for the treatment of a variety of cancers . LOAd70310 to 3 × 1011 virus particles in combination with low-dose cyclophosphamide. No dose-limiting toxicity was observed, and hence, no MTD was identified in this study. In terms of anti-tumor efficacy, 4 out of 10 evaluable patients had stable disease at 3 months. Patients treated with the virus had a short-term elevation in pro-inflammatory cytokines and had an increase in tumor infiltration by lymphocytes, as determined by the immunohistochemistry of tumor biopsies before and after the treatment. In some patients, systemic induction of tumor-specific CD8+ T cells was observed. Furthermore, an upregulation in the levels of PD-L1 in the tumor was observed after virus treatment, suggesting that the efficacy of the virus could be enhanced by combining it with PD-L1 inhibitors. Hence, there are active clinical studies testing the safety and efficacy of ONCOS-102 in combination with PD-L1 inhibitors such as durvalumab (NCT02963831) and pembrolizumab (NCT03003676).Another oncolytic adenovirus being tested in clinical studies is ONCOS-102 . ONCOS-102 is a chimeric adenovirus constructed from adenovirus type 3 and 5, and is armed with the cytokine GM-CSF . Thus faRNA viruses belonging to different families including coronaviridae, picornaviridae, reoviridae, retroviridae, rahabdoviridae and togaviridae have been studied for their oncolytic activities . One comRas and the impairment in type-I interferon (IFN) signaling [Clinicaltrials.gov (accessed in 1 November 2020), a total of 20 clinical trials have been completed with this virus . The virus has been studied as a monotherapy or in combination with other therapeutics for the treatment of a multitude of cancers including metastatic breast cancer, advanced-stage head and neck cancer, metastatic ovarian cancer, malignant gliomas, prostate cancer and metastatic melanoma. Out of the total 20 completed trials, Reolysin was used as monotherapy in 5 studies, and in the remaining 15 studies it was combined with chemotherapeutics such as gemcitabine, irinotecan, docetaxel, carboplatin, paclitaxel and cyclophosphamide  for five consecutive days every 4 weeks. Grade 1 and 2 toxicities included fever, fatigue and headaches, which were independent of the virus doses. Virus-neutralizing antibodies were developed in all patients, with the peak titer detected 4 weeks after the first injection. Evidence of virus localization and replication in tumor was observed in three patients. The study report did not mention anything about anti-tumor efficacy, perhaps because no anti-tumor efficacy was observed.Vidal et al. reported the first clinical study on intravenous delivery of Reolysin . In this8 to 3 × 109 TCID50. Dose-limiting toxicity was not reached, and the common treatment-related toxicities included fatigue and fever. A virus-neutralizing antibody was developed in all patients during the course of treatment. Furthermore, virus shedding was observed in 6 out of 18 patients, and the patients showing virus shedding appeared to be more responsive to the treatment. In this study, the overall clinical benefit rate was 45%: one patient experienced partial response and seven attained stable disease.Gollamudi et al. reported results from another clinical study involving intravenous administration of Reolysin . In this10 TCID50 on days 1–5 of each 4 week cycle. Similar to previous Phase I trials, the treatment was well tolerated. Productive reovirus replication was observed in the tumor biopsies of two patients. Unfortunately, no objective response was observed in this study. Likewise, results from another Phase II trial were reported by Mite et al. (NCT00503295). In this study, 43 patients with bone and soft tissue sarcoma metastatic to the lung were recruited. Patients were treated intravenously with Reolysin every 28 days. Toxicities were mild to moderate, including fever, chills, fatigue, diarrhea, cough, dyspnea, neutropenia and thrombocytopenia. Overall, 14 patients experienced stable disease for more than 2 months, and 5 patients had stable disease for more than 6 months.The first Phase II trial for intravenous monotherapy of Reolysin was initiated in 2008 . In this8 and 1 × 1010 TCID50. In the second stage, patients received a higher dose of radiation (36 Gy) followed by 2, 4 or 6 doses of 1 × 1010 TCID50 virus. The combination treatments were found to be safe with mild (grade 1 to 2) toxicities. Two of seven evaluable patients in the low-dose radiation group showed partial response, and five patients had stable disease. Likewise, in the high-dose radiation treatment, five of seven evaluable patients experienced partial response and two had stable disease. No virus shedding was detected in blood, urine, stool and sputum of the patients. Given the excellent safety profile and better efficacy, compared to previous studies using reovirus as monotherapy, the authors concluded that this combination should be evaluated in newly diagnosed patients receiving radiation with curative intent.While clinical studies with Reolysin as monotherapy have demonstrated that the virus is safe, the lackluster efficacy of the virus as monotherapy has prompted investigators to combine it with other therapeutics. Over a dozen clinical studies encompassing different phases of trials have been completed so far with Reolysin in combination with radiation, chemo- or biological therapies. Harrigton et al. reported the findings of a Phase I trial combining reovirus in patients receiving palliative radiotherapy . In tota10 TCID50 reovirus. Overall, 3 out of 16 patients experienced dose-limiting toxicity, with 2 patients having liver enzymes increased to grade 3, and 1 patient with levels of troponin elevated to grade 3. The increase in liver enzymes was found to be transient and reversible. In this combination treatment, neutralizing-antibody responses to reovirus were delayed and attenuated. Following this study, a Phase II study was initiated to evaluate the safety and efficacy of reovirus in combination with gemcitabine in patients with metastatic pancreatic cancer (NTC00998322). As of today, this study has been completed but findings of the study have not been published. A variety of other chemotherapeutics including carboplatin, irinotecan, cyclophosphamide, paclitaxel and docetaxel have been studied in combination with Reolysin in Phase I and/or Phase II trials against a multitude of cancers. Finally, a Phase III trial of Reolysin in combination with carboplatin and paclitaxel has been completed in patients with head and neck cancer. Findings of the study have not been reported yet.Lolkema et al. reported results of the first clinical study combining reovirus with a chemotherapy . In thisReolysin has also been studied in combination with other biological therapeutics. The first biological therapeutic to be combined with Reolysin was bevacizumab, a monoclonal antibody against vascular endothelial growth factor. In a Phase I trial, colorectal cancer patients with mutant KRAS were treated with Reolysin and bevacizumab together with the chemotherapeutics irinotecan, leucovorin and 5-fluorouracil (NCT01274624). The study has been completed, but the results have not been published yet. Additionally, several clinical studies combining reovirus with checkpoint inhibitors (CKIs) are currently underway .The field of oncolytic virotherapy is rapidly growing, with thousands of preclinical studies reported, and over 100 clinical trials performed thus far. The approval of T-VEC by the FDA in 2015 amplified the interest of cancer researchers and clinicians in this novel therapeutic approach. Apart from T-VEC, there are many oncolytic viruses that have completed different phases of clinical studies. From all the clinical trials performed so far, oncolytic viruses appear to be safe at maximum feasible doses, and in most cases, the maximum tolerable doses have not been reached. While OVs have shown excellent safety profiles, their anti-tumor efficacies are modest at best. Nevertheless, for most viruses, the MTD has not been reached, and it is likely that their anti-tumor efficacies could be increased with future advancements in virus manufacturing technology. Alternatively, novel viruses with higher anti-tumor potency could be generated, which may allow researchers to achieve maximum anti-tumor benefits at doses that are feasible with the current manufacturing process. For example, our group created a chimeric poxvirus through recombination among nine poxviruses, encompassing different strains of VACV and different species of poxvirus . The chiMost of clinical trials, including those for T-VEC, have used intratumoral route for virus administration. The reason for using intratumoral administration is to avoid virus neutralization by antibodies and virus sequestration by macrophages, which could severely impede OVs, especially during repeated injections. The downside of the intratumoral route for virus injection is that the virus could not be administered in tumors that are inaccessible for direct injections. Furthermore, once a cancer has been metastasized, it is not possible to find all the metastatic nodules and inject them. While some studies have shown that injection of virus in one tumor can lead to regression of distant un-injected tumors, this phenomenon of abscopal effect has been observed only in small subset of patients. Recently, some clinical studies have used the systemic route for the delivery of oncolytic viruses, showing the feasibility of systemic injections of OVs in patients. The anti-tumor efficacy achieved through systemic injections of viruses has been modest, just as is the case for intratumoral injections of OVs.Cancer is a complex disease that often requires a complex treatment comprising a combination of several therapeutic approaches. Results from clinical trials suggest that oncolytic viruses as monotherapy are less likely to achieve optimum therapeutic benefits. However, oncolytic viruses appear to be good candidates for combination with other therapeutic approaches, especially immunotherapy. Oncolytic viruses have been shown to subvert immune-suppressive microenvironments in tumors, making them conducive for the effectiveness of immunotherapeutics (reviewed in ). A numbIn summary, the field of oncolytic virotherapy has made dramatic strides in the last two decades, culminating in the approval of the first OV in the Western world. With many oncolytic viruses having completed Phase II trials, it is likely that more oncolytic viruses, perhaps in combination with immunotherapeutics, will soon receive approval from regulatory agencies for the treatment of different malignancies.


High-dose-rate interstitial brachytherapy (HDR-ISBT) is recommended to obtain a better local tumor control for uterine cancer patients in specific situations such as bulky lesions, an extension to the lateral parametrium, or tumors with irregular shapes. Our group uses real-time transrectal ultrasonography (TRUS) to guide freehand interstitial needle insertion. Occasionally, target tumors locate deeper beyond the rectum and cannot be visualized by TRUS. CT can guide needles to deeply located tumors, but in such cases, repeated image obtainment is required to achieve ideal needle localization. In this report, we present nine cases of patients who underwent HDR-ISBT for deeply situated tumors guided by a combination of transrectal and transabdominal ultrasonography (TR/TA-US).Nine uterine cancer patients whose tumors were located deeper than the reach of TRUS and underwent HDR-ISBT guided by TR/TA-US were presented. All nine cases had no distal organ metastasis and underwent external beam radiation therapy (EBRT) to the pelvic region for 45–50.4 Gy in 25–28 fractions followed by boost HDR-ISBT for deeply situated tumors guided by TR/TA-US.There were seven cervical cancer and two endometrial cancer patients: six with extensive uterine corpus invasion, one cervical cancer with massive pelvic lymph node metastasis, one cervical cancer with postoperative pelvic recurrence, and one with left ovarian direct tumor invasion. The median follow-up period was 15 months (range 3–28 months). The average clinical target volume at the time of first HDR-ISBT was 131 ml (range 44–335 ml). The linear distance from the vaginal entrance to the deepest part of the tumor at first time brachytherapy of nine cases was 14.0 (9.0–17.0) cm. HDR-ISBT dose fractionation was 24–30 Gy in four or five fractions. Seven out of nine cases had no local recurrence in the follow-up period. One had local in-field recurrence 25 months after HDR-ISBT. Another case with carcinosarcoma could not obtain local control and underwent salvage hysterectomy for a residual uterine tumor 11 months after HDR-ISBT. Four cases had extra-field recurrence in lymph nodes or distant organs.In brachytherapy for gynecologic malignancies, deeply situated tumors located out of reach of TRUS may obtain favorable local control by HDR-ISBT guided with TR/TA-US. Brachytherapy plays an important role in cervical cancer for definitive radiation therapy (RT) because it can give a relatively significant dosage while preserving the surrounding organ at risk (OAR) , 2. SmalTumors tend to expand laterally with the cardinal ligament in locally advanced cervical cancer. In specific clinical situations, such as large lesions, extension to the lateral parametrium, or pelvic sidewall, the American Brachytherapy Society (ABS) guidelines recommend high-dose-rate interstitial brachytherapy (HDR-ISBT) for such cervical cancer patients . It was CT can guide needles to deeply located tumors, but in such cases, repeated image obtainment is required to achieve ideal needle localization. In such cases, we used transabdominal ultrasonography (TAUS) to obtain real-time visualization of a tumor and insert a needle to reduce this risk of normal tissue injury and ensure that the needle tip is within the target.Here, we presented nine cases of patients who underwent HDR-ISBT for deeply situated tumors guided by a combination of transrectal and transabdominal ultrasonography (TR/TA-US).Uterine cancer patients who underwent HDR-ISBT for deeply situated tumors guided by TR/TA-US between January 2019 and November 2020 were included in this report.The patients were treated with a combination of pelvic external beam RT (EBRT) and brachytherapy. In all cases, EBRT was up to a dose of 50–50.4 Gy at 1.8–2.0 Gy per fraction in 25–28 fractions with 5 fractions per week. The initial 30–41.4 Gy was delivered to the whole pelvis, and then pelvic irradiation was delivered with a 4-cm width of the central shield (CS), reducing OAR exposure. The initiation of CS depended upon tumor shrinkage. After the CS was inserted or EBRT was accomplished, HDR-ISBT was performed in 1–2 sessions/week. In seven of the nine cases, the needle and applicator were removed after irradiation, and applicator insertion was performed at each treatment (multiple implants). In the remaining two cases, more emphasis was placed on the difficulty of the needle insertion technique into the target, and in order to avoid multiple needle insertions, irradiation was performed every day, twice daily irradiation at 6-h intervals without removing the needles, and needle insertion was performed only once throughout the entire period.2, during the EBRT period. Uterine body cancer patients were treated with RT alone.Cervical cancer patients were treated with concurrent chemotherapy basically with weekly cisplatin at 40 mg/mAll patients lay in lithotomy position after saddle block anesthesia or local anesthesia and intravenous sedation. For better pelvic visualization of US, Foley catheterization was performed, and 100 ml of normal saline was instilled into the urinary bladder retrogradely to reduce poor visualization due to intestinal gas.Transperineal freehand interstitial needle insertion was guided by TR/TA-US. The quality of TA-US is dependent on the examiner’s experience. Adequately inflating the bladder with more than 100 ml of saline is essential in order to obtain a favorable image. It is also important to avoid the pubic bone, apply adequate echo jelly, and compress the probe to the abdominal wall. If these points are observed, even residents with limited experience also can insert needles under TA-US guidance.After needle insertion, ICBT applicators, tandem, and ovoid/cylinder were inserted. HR) at HDR-ISBT is delineated on this CT using MRI taken immediately before the initial HDR-ISBT and TRUS as a reference . Dose calculation of HDR-ISBT was based on CT. Dose constraints of HDR-ISBT and the goal are to deliver more than 6 Gy to CTVHR D90 (dose covering 90% of the CTVHR) and total CTVHR D90 combining EBRT and brachytherapy to be >85 Gy equivalent dose in 2-Gy fractions (EQD2). The rectum and bladder were contoured as OARs. Dose constraints for OARs were determined as follows: bladder D2cc < 90 Gy EQD2 and rectum D2cc < 75 Gy EQD2.At each brachytherapy session, a CT image of 2-mm slice thickness was taken by a CT simulator  situated in the operating room with the patient lying in lithotomy position with the applicators in place. High-risk clinical target volume .All brachytherapy was carried out by All patients were followed up by CT and/or MRI scans performed 1–3 months after radiotherapy, and physical examination and blood tests were performed regularly every 1–6 months. Adverse events were assessed by Common Terminology Criteria for Adverse Events (CTCAE) version 4.0.All analyses were performed using computer software .This study was also approved by the Institutional Review Board of our hospital, the Ethics Committee of National Cancer Center Hospital (approved number 2017-091), according to the ethical standards laid down in the Declaration of Helsinki.Nine uterine cancer patients were entered into this report. The patient’s demographics are summarized in HR at first HDR-ISBT was 131 ml (range 44–335 ml). The median linear distance from the vaginal introitus to the deepest part of the tumor at first time brachytherapy was 14.0 cm (9.0–17.0 cm). The prescribed dose of HDR-ISBT was 24–30 Gy in four or five fractions. Median CTVHR D90 (EQD2) was 85 Gy (73–93 Gy). Median bladder D2cc (EQD2) was 71 Gy (58–77 Gy). Median rectum D2cc (EQD2) was 70 Gy (48–85 Gy).The median follow-up period was 15 months (range 3–28 months). The median volume of CTVAn example of an MRI taken within 1 week before the first brachytherapy and TAUS taken during the brachytherapy of three typical cases is demonstrated in It has been demonstrated that HDR-ISBT should be offered for large tumors with irregular shapes , 14–16. HR D90 for all nine cases was 85 Gy (range 73–103 Gy), which is above the recommended dose by ABS and GEC-ESTRO guidelines (2cc (EQD2) and median rectum D2cc (EQD2) were also below the recommended dose by ABS and GEC-ESTRO guidelines.In this report, the median CTVrange 73–03 Gy, whidelines , 14. MedEven though patients included in this study had extremely massive tumors or tumors in locations where it is impossible to treat HDR-ISBT with usual methods, seven out of nine patients achieved local control. Moreover, even tumors were located challenging to treat locations; no grade ≥ 3 adverse events were reported related to HDR-ISBT under TR/TA-US guidance. Therefore, it is likely that deeply situated tumors that localized out of the reach of TRUS may obtain favorable dose coverage and have a possibility to achieve a better prognosis by HDR-ISBT guided by TR/TA-US.In this report, transperineal needle insertion was primarily used. Interstitial transvaginal needles can sometimes be used for uterine body involvement, and the depth of transvaginal needles can be monitored using TA-US. However, due to the space limitation or interference from the other applicators, it is sometimes difficult to change the needle angle freely with the transvaginal approach. Therefore, in our institution, the transperineal approach is generally preferred.The limitations of this report are that the number of patients included was only nine, the follow-up period was short, and there was no control cohort to compare clinical outcomes of this new method. Therefore, it is difficult to draw firm conclusions from this report. The limiting factor of TA-US is that the deep pelvic lesion is not always well delineated due to bowel gas and other factors such as thick subcutaneous fat tissue, and TA-US cannot be used as real-time needle insertion guidance in such cases. Generally, lymph node or ovarian metastases are boosted by EBRT, and it is unusual for HDR-ISBT to be chosen as a modality to deliver a boost dose. However, we thought that even with the technique of stereotactic body RT, delivering adequate tumoricidal doses to such lesions is difficult. Brachytherapy has the physical advantage of being able to deliver a localized high dose of radiation with rapid fall-off and capable of sparing surrounding adjacent normal tissues, as well as the technical feasibility of inserting interstitial needles with the new technique presented in this article; therefore, we decided to deliver the boost dose with HDR-ISBT for these patients. With this new technique, it is possible to treat challenging diseases that are otherwise impossible to treat with current treatment methods. Further accumulation of patients, experience, and knowledge is needed to implement this novel technique to spread widely.In uterine cancer treatment, deeply situated tumors that localized out of the reach of TRUS may obtain favorable dose distribution by HDR-ISBT guided with TR/TA-US.The raw data supporting the conclusions of this article will be made available by the authors, without undue reservation.The studies involving human participants were reviewed and approved by the Ethics Committee of National Cancer Center Hospital (approved number 2017-091). The patients/participants provided their written informed consent to participate in this study. Written informed consent was obtained from the individual(s) for the publication of any potentially identifiable images or data included in this article.TaK, AT, ToK, KT, KI, KO, YN, JI, and HI contributed to patients’ treatment and data collection. TC, HO, and SN contributed to data analysis and figure creation. All the authors contributed to manuscript editing and approved it.We received a grant for the cost of this study from the hospital's collaborative research fund C2019-121.JI reports grants from Elekta, during the conduct of the study; personal fees from Heka-Bio; personal fees from Alpha-TAU; grants and others from ITOCHU; and personal fees from Palette Life Science, outside the submitted work. HI reports grants and personal fees from Heka-Bio, grants from CICS, grants from Elekta KK, personal fees from AstraZeneca, personal fees from Itochu, personal fees from HIMEDIC, and personal fees from Varian, outside the submitted work. KI reports personal fees from Boston Scientific Japan, outside the submitted work. TaK reports personal fees from Astra Zeneca, outside the submitted work.The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.


Cardiovascular system involvement in coronavirus disease-2019 (COVID-19) has gained great interest in the scientific community.Several studies reported increased morbidity and mortality among COVID-19 patients who had comorbidities, especially cardiovascular diseases like hypertension and acute coronary syndrome (ACS). COVID-19 may be associated with cardiovascular complications as arrhythmia, myocarditis, and thromboembolic events. We aimed to illustrate the interactions of COVID-19 disease and the cardiovascular system and the consequences on clinical decision as well as public health.COVID-19 has negative consequences on the cardiovascular system. A high index of suspicion should be present to avoid poor prognosis of those presenting with unusual presentation. Coronavirus disease-2019 pandemic is a major health problem that affected hundreds of countries and territories. It results in more than 200 million infected cases and more than four million deaths worldwide , includiSevere acute respiratory syndrome coronavirus 2 (SARS-CoV2) infection is the cause of COVID-19 . SARS-CoIndirect cardiac injury may be attributed to immune system dysregulation with the release of cytokines, thrombo-inflammation, microcirculation dysfunction, endothelial cell damage, and dysregulation of the renin–angiotensin–aldosterone system (RAAS) . CardiacA preexisting cardiovascular disease is a risk factor for severe COVID-19 due to increased expression of ACE2 receptors , 28. IncPhysiologic stress with hypoxemia is a contributing factor that may result in myocardial ischemia, tachycardia, and several cardiovascular adaptations –35.Partly, arrhythmias may be attributable to hypoxia, inflammatory stress, and abnormal metabolism in SARS-CoV-2-infected patients with or without preexisting CVD . VariousHypoxemia is associated with a significant reduction in the energy supply and increases anaerobic metabolism resulting in intracellular acidosis and excess oxygen free radicals that destroy the cell membrane , 38. As Malavazos et al. proposed that the epicardial adipose tissue (EAT) contributes to the development of myocarditis. EAT has a direct anatomical and functional relationship to the myocardium, and both share the same microcirculation. During SARS-CoV2 infection, EAT is highly infiltrated with macrophages and cytokines like IL-6 which can reach the pericardium and myocardium directly via the vasa vasorum or through paracrine pathways .The hypercoagulable state was a prominent finding in COVID-19 patients in several reports. Laboratory findings in these patients included: high serum ferritin . High leIncreased morbidity and mortality in COVID-19 may be attributed to several risk factors including male gender, old age, obesity, hypertension, diabetes, and established cardiovascular and cerebrovascular disease , 43. PooComorbid illnesses are prevalent in severe COVID-19 cases. Cardiovascular comorbidities were reported to be a key player due to its effect on prognosis. It has been reported that CVD increased the case-fatality rate by 10.5%, compared to 7.3%, 6.3%, 6%, and 5.6% for DM, chronic obstructive pulmonary disease (COPD), hypertension, and cancers, respectively . SimilarManagement of myocardial dysfunction during the current pandemic is a great challenge. Several factors are to be considered including the challenges to perform cardiac imaging, hemodynamic assessment, and endomyocardial biopsies on the one side and the hazard of viral infection to patients and healthcare professionals (HCP) as well as contamination of healthcare facilities on the other side , 56.Cardiac involvement may occur several days after influenza-like symptoms . The freA large spectrum of CV complications can develop in COVID-19 patients Fig. . PatientMyocardial injury is defined as a remarkable rise in troponin levels. It may occur due to ischemic or non-ischemic myocardial injury as myocarditis . Acute mIncreased incidence of AMI has been reported with several respiratory viruses including influenza and other coronavirus species . Severe Heart failure may be the principal clinical feature of COVID-19 infection , 62. TheArrhythmias may associate or complicate COVID-19 infection . PalpitaPatients suffering from COVID-19 infection are also at high danger of developing VTE. Thrombotic events were more probable in critically ill COVID-19 patients despite the use of proper anticoagulation . Cui et Researchers reported an increased incidence of out-of-hospital cardiac arrest during the COVID-19 pandemic in 2020 compared to the same period during 2019 . SeveralNo specific ECG changes are described in COVID-19 patients. This may be attributed to the subtle myocardial involvement associated with infection . So, theAny elective cardiac imaging should be delayed until the patient is considered non-infectious . TransthThe elevated level of cardiac biomarkers in COVID-19 is a prominent feature that indicates cardiac involvement and is associated with poor clinical outcome , 78. EleThe levels of the biomarker of hemodynamic myocardial stress and HF which is B-Type Natriuretic Peptide/N-Terminal B-Type Natriuretic Peptide (BNP/NT-proBNP) are commonly elevated among patients with severe inflammatory disorders including respiratory ones. The high levels of BNP/NT-proBNP in a patient with SARS-CoV-2 infection may suggest the presence/magnitude of pre-existing cardiac condition, especially the acute hemodynamic stress and/or the right ventricular strain linked to COVID-19 .High levels of inflammatory markers of cardiac injury have been noted to be associated with electrocardiographic abnormalities in COVID-19 .Significant coagulation abnormalities exist in hospitalized patients with severe COVID-19 illness . D‐dimerFurthermore, an abnormal immune response may be detected in COVID-19 patients as high expression of ACE2 receptors in the SARS-CoV-2 infected cells, high levels of IL-1, IL-6, IL-8, and IL-10 . High leThe differential diagnosis of cardiovascular manifestations in presumed or evident COVID-19 infection is complicated and tricky. Various respiratory symptoms as shortness of breathing and chest pain are also cardiac symptoms. Dyspnea may also precede or associate other cardiac manifestations. Soon, a precise and quick determination of cardiovascular problems, in this case, is vital . CliniciNo specific treatment for COVID-19 has been reported or approved until the time of writing this review. The treatment is symptomatic, and some drugs were used due to their potential antiviral activity against different viruses rather than COVID-19.It is important to protect the cardiovascular system in COVID-19 cases to prevent chronic cardiac damage .The increased incidence of thromboembolic events in COVID-19 cases reported in several studies emphasized the benefits of using anticoagulants as a line of treatment in these cases. Low molecular weight heparin (LMWH) is commonly used in hospital settings and was associated with decreased morbidity and mortality . ThromboThe potential impact of acetylsalicylic acid (ASA) therapy has been questioned and still under investigation . NeverthThe acute treatment of arrhythmias and MI is similar to that in the general population. The same guidelines apply   with consideration of the safety of healthcare professionals (HCP) , 88. PriAdjusted fluid therapy management is critical in COVID-19 patients to avoid cardiovascular complications especially in those with ARDS who are liable to right heart failure .There is an argument about the use of some drugs used for the treatment of CV diseases, especially RAS blocking drugs as ACEIs and angiotensin receptors blocking agents (ARBs) in patients with COVID-19 , 92 Fig, and theStatins have potential value in COVID-19. It may reduce risk of severe disease and hospitalization due to anti-inflammatory and immune modulating properties as well as antilipid effect as lipid metabolism contributes to pathogenesis of SARS-CoV-2 infection . On the Severe rhabdomyolysis or increased liver enzymes have been reported in some cases with COVID-19, and in such cases, it may be wise to stop statin therapy till the condition improves , 109.Some drugs that are used in treatment protocols of COVID-19 may have some adverse events on the CVS or interact with drugs used for the treatment of CV conditions , risk of conduction abnormalities, and those receiving drugs that prolong QT interval . LopinavFor infection control purposes during the COVID-19 pandemic, diagnostic testing before any intervention is highly recommended . BesidesPublic health focuses on discovering and modernizing the environmental factors associated with diseases. The role of public health is on the individual or at the community level .During the current pandemic, it is impossible to treat all patients, especially in critical care settings . The neeTreatment strategies with controversial value will be a great challenge for HCR allocation decisions as some will see these strategies as life-saving and others see it of unproven efficacy and un-necessary action . So, theUsually, Medicine tells us what we can do; however, ethics tells us what we should do. Principles of medical ethics include: autonomy, beneficence, non-maleficence, and justice . GeneralMost guidelines and clinical practice procedures make prioritization of patients with chronic cardiac conditions like chronic coronary syndrome based on risk stratification , 114. InThe way of life and mental wellbeing sequel of COVID-19 may increment the load of CVD. Lockdown and social distancing promote sedentary behavior, sudden alterations in lifestyle, and unhealthy diets . The phyCOVID-19 pandemic has several immediate and long-term cardiovascular complications. Cardiovascular diseases have deleterious effects on clinical outcomes. Overall cardiovascular health is affected by the COVID-19 pandemic either directly or indirectly. Clinicians should have a high index of suspension and be very cautious in drug selection during the management of COVID-19 cases. Cardiovascular emergencies in COVID-19 patients are managed similar to the general population with appropriate considerations to prevent transmission of infection.COVID-19 is associated with negative consequences on the cardiovascular system. Meanwhile, preexisting cardiovascular complications are associated with poor prognosis. Knowing this fact should help improve local strategies set for management of cardiac problems during the COVID-19 pandemic.