Medical physics in radiotherapy: The importance of preserving clinical responsibilities and expanding the profession's role in research,education, and quality control

Medical physicists have long had an integral role in radiotherapy. In recent decades, medical physicists have slowly but surely stepped back from direct clinical responsibilities in planning radiotherapy treatments while medical dosimetrists have assumed more responsibility. In this article, I argue against this gradual withdrawal from routine therapy planning. It is essential that physicists be involved, at least to some extent, in treatment planning and clinical dosimetry for each and every patient; otherwise, physicists can no longer be considered clinical specialists. More importantly, this withdrawal could negatively impact treatment quality and patient safety. Medical physicists must have a sound understanding of human anatomy and physiology in order to be competent partners to radiation oncologists. In addition, they must possess a thorough knowledge of the physics of radiation as it interacts with body tissues, and also understand the limitations of the algorithms used in radiotherapy. Medical physicists should also take the lead in evaluating emerging challenges in quality and safety of radiotherapy. In this sense, the input of physicists in clinical audits and risk assessment is crucial. The way forward is to proactively take the necessary steps to maintain and advance our important role in clinical medicine.     

The status of medical physics in radiotherapy in China

PurposeTo present an overview of the status of medical physics in radiotherapy in China, including facilities and devices, occupation, education, research, etc.Materials and methodsThe information about medical physics in clinics was obtained from the 9-th nationwide survey conducted by the China Society for Radiation Oncology in 2019. The data of medical physics in education and research was collected from the publications of the official and professional organizations.ResultsBy 2019, there were 1463 hospitals or institutes registered to practice radiotherapy and the number of accelerators per million population was 1.5. There were 4172 medical physicists working in clinics of radiation oncology. The ratio between the numbers of radiation oncologists and medical physicists is 3.51. Approximately, 95% of medical physicists have an undergraduate or graduate degrees in nuclear physics and biomedical engineering. 86% of medical physicists have certificates issued by the Chinese Society of Medical Physics. There has been a fast growth of publications by authors from mainland of China in the top international medical physics and radiotherapy journals since 2018.ConclusionsDemand for medical physicists in radiotherapy increased quickly in the past decade. The distribution of radiotherapy facilities in China became more balanced. High quality continuing education and training programs for medical physicists are deficient in most areas. The role of medical physicists in the clinic has not been clearly defined and their contributions have not been fully recognized by the community.     

Results of heavy ion radiotherapy

The potential of heavy ion therapy for clinical use in cancer therapy stems from the biological parameters of heavy charged particles and their precise dose localization. Biologically, carbon, neon, and other heavy ion beams (up to about silicon) are clinically useful in overcoming the radioresistance of hypoxic tumors, thus increasing the biological effectiveness relative to low linear energy transfer x-ray or electron beams. Cells irradiated by heavy ions show less variation in cell-cycle-related radiosensitivity and decreased repair of radiation injury. The physical parameters of these heavy charged particles allow precise delivery of high doses to tumors while minimizing irradiation of normal tissues. Clinical use requires a close interaction between radiation oncologists, medical physicists, accelerator physicists, engineers, computer scientists, and radiation biologists.     

Preprint Déjà Vu

Twenty‐five years ago, in August 1991, I spent a couple of afternoons at Los Alamos National Laboratory writing some simple software that enabled a small group of physicists to share drafts of their articles via automated email transactions with a central repository. Within a few years, the site migrated to the nascent WorldWideWeb as arXiv.org, and experienced both expansion in coverage and heavy growth in usage that continues to this day. In 1998, I gave a talk to a group of biologists—including David Lipman, Pat Brown, and Michael Eisen—at a meeting at Cold Spring Harbor Laboratory (CSHL) to describe the sharing of articles “pre‐publication” by physicists. The talk was met with some enthusiasm and prompted the “e‐biomed” proposal in the following spring by then NIH director Harold Varmus. He encouraged the creation of an NIH‐run electronic archive for all biomedical research articles, including both a preprint server and an archive of published peer‐reviewed articles, which generated significant discussion.     

The role of medical physics in prostate cancer radiation therapy

Medical physics, both as a scientific discipline and clinical service, hugely contributed and still contributes to the advances in the radiotherapy of prostate cancer. The traditional translational role in developing and safely implementing new technology and methods for better optimizing, delivering and monitoring the treatment is rapidly expanding to include new fields such as quantitative morphological and functional imaging and the possibility of individually predicting outcome and toxicity. The pivotal position of medical physicists in treatment personalization probably represents the main challenge of current and next years and needs a gradual change of vision and training, without losing the traditional and fundamental role of physicists to guarantee a high quality of the treatment. The current focus issue is intended to cover traditional and new fields of investigation in prostate cancer radiation therapy with the aim to provide up-to-date reference material to medical physicists daily working to cure prostate cancer patients. The papers presented in this focus issue touch upon present and upcoming challenges that need to be met in order to further advance prostate cancer radiation therapy. We suggest that there is a smart future for medical physicists willing to perform research and innovate, while they continue to provide high-quality clinical service. However, physicists are increasingly expected to actively integrate their implicitly translational, flexible and high-level skills within multi-disciplinary teams including many clinical figures (first of all radiation oncologists) as well as scientists from other disciplines.     

The medical physics specialization system in Poland

This paper presents the situation of the profession of medical physicists in Poland. The official recognition of the profession of medical physicist in Polish legislation was in 2002. In recent years, more and more Universities which have Physics Faculties introduce a medical physics specialty. At present, there are about 15 Universities which offer such programmes. These Universities are able to graduate about 150 medical physicists per year. In 2002, the Ministry of Health introduced a programme of postgraduate specialization in medical physics along the same rules employed in the specialization of physicians in various branches of medicine. Five institutions, mostly large oncology centres, were selected as teaching institutions, based on their experience, the quality of the medical physics professionals, staffing levels, equipment availability, lecture halls, etc. The first cycle of the specialization programme started in 2006, and the first candidates completed their training at the end of 2008, and passed their official state exams in May 2009. As of January 2016, there are 196 specialized medical physicists in Poland. Another about 120 medical physicists are undergoing specialization.The system of training of medical physics professionals in Poland is well established. The principles of postgraduate training and specialization are well defined and the curriculum of the training is very demanding. The programme of specialization was revised in 2011 and is in accordance with EC and EFOMP recommendations.     

Contribution of case reports to brain metastases research: systematic review and analysis of pattern of citation

Research activity related to different aspects of prevention, prediction, diagnosis and treatment of brain metastases has increased during recent years. One of the major databases (Scopus) contains 942 scientific articles that were published during the 5-year time period 2006–2010. Of these, 195 (21%) reported on single patient cases and 12 (1%) were reports of 2 cases. Little is known about their influence on advancement of the field or scientific merits. Do brain metastases case reports attract attention and provide stimuli for further research or do they go largely unrecognized? Different measures of impact, visibility and quality of published research are available, each with its own pros and cons. For the present evaluation, article citation rate was chosen. The median number of citations overall and stratified by year of publication was 0, except for the year 2006 when it was 2. As compared to other articles, case reports remained more often without citation (p<0.05 except for 2006 data). All case reports with 10 or more citations (n = 6) reported on newly introduced anticancer drugs, which commonly are prescribed to treat extracranial metastases, and the responses observed in single patients with brain metastases. Average annual numbers of citations were also calculated. The articles with most citations per year were the same six case reports mentioned above (the only ones that obtained more than 2.0 citations per year). Citations appeared to gradually increase during the first two years after publication but remained on a generally low or modest level. It cannot be excluded that case reports without citation provide interesting information to some clinicians or researchers. Apparently, case reports describing unexpected therapeutic success gain more attention, at least in terms of citation, than others.     

Plant science research productivity in Chile during the past 20 years

The purpose of this study was to carry out a bibliometric analysis of the articles published in Chile during 1987-2006 that were categorized into the Plant Science discipline by ISI. The data was extracted from the Web of Science datábase, obtaining a total of 911 articles for analysis. Almost half of the articles were the outcome of an international collaboration, the United States being the country with more collaborative links with Chile within this discipline. A list was made with the 10 most-cited articles and 10 most frequently used journals. The analysis showed that almost 50% of the articles were concentrated in 10 different journals. The number of articles produced each year revealed a steady growth in scientific production since 1987. This is probably related to the progressive interaction between industry and public-research institutions.     

Editorial: The role of medical physics in lung SBRT

Stereotactic body radiation therapy (SBRT) has become a standard treatment for non-operable patients with early stage non-small cell lung cancer (NSCLC). In this context, medical physics community has largely helped in the starting and the growth of this technique. In fact, SBRT requires the convergence of many different features for delivering large doses in few fractions to small moving target in an heterogeneous medium. The special issue of last month, was focused on the different physics challenges in lung SBRT. Eleven reviews were presented, covering: imaging for treatment planning and for treatment assessment; dosimetry and planning optimization; treatment delivery possibilities; image guidance during delivery; radiobiology. The current cutting edge role of medical physics was reported. We aimed to give a complete overview of different aspects of lung SBRT that would be of interest to both physicists implementing this technique in their institutions and more experienced physicists that would be inspired to start research projects in areas that still need further developments. We also feel that the role that medical physicists have played in the development and safe implementation of SBRT, particularly in lung region, can be taken as an excellent example to be translated to other areas, not only in Radiation Oncology but also in other health sectors.     

基于文献计量的植物雌雄异株研究进展

雌雄异株植物是研究植物性别的理想材料,同时作为生态系统的重要组成部分,对生物多样性的维持与保护起着重要作用。该文从文献计量学角度综述了雌雄异株植物相关研究的进展。通过检索Web of Science(WOS)平台的SCI-E数据库和CNKI数据库的有关雌雄异株研究的文献数据,从文献年代分布、期刊分布、研究国家与机构、核心作者和高引论文等方面进行了分析,并借助CitespaceⅢ信息可视化软件绘制雌雄异株植物研究的科学知识图谱,总结了雌雄异株研究的热点和前沿。结果表明:WOS数据库中,雌雄异株植物研究呈现快速上升趋势,就发文总量来看,发文前五的国家为美国、日本、加拿大、英格兰和中国。其中,美国发文量占比为31.03%;中国科学院为发文量最多的机构,发文占比3.36%,其次为牛津大学(2.613%),多伦多大学位列第三(2.427%);中国,巴西和印度三国,西班牙马萨里克大学和北京林业大学两个研究机构近5年来在该领域发文增量较快。论文主要集中在植物科学、环境科学与生态学和遗传学等学科。载文量前十位的期刊累计载文占比高达24.13%,发文量最多的期刊为American Journal of Botany,占总发文量的6.07%,其次为Evolution(2.80%),Annals of Botany(2.52%)排名第三。发文最多的作者为捷克科学院的VYSKOT B,发文占总数的2.57%,高引论文大多出自美国学者之手。从CNKI数据库看,西华师范大学、北京林业大学和河南师范大学发文数量位列前三,发文量最高的期刊为《生命世界》,占总发文量的3.00%。综合Web of Science和CNKI两大数据库的文献来看,青杨和番木瓜作为研究雌雄异株植物的模式植物,近年发文较多。当前的研究热点主要集中在雌雄性别决定,繁殖代价,雌雄个体对环境因子的响应差异等方面。     

Surveying trends in radiation oncology medical physics in the Asia Pacific Region

ObjectiveOur study aims to assess and track work load, working conditions and professional recognition of radiation oncology medical physicists (ROMPs) in the Asia Pacific Region over time.MethodsA structured questionnaire was mailed in 2008, 2011 and 2014 to senior medical physicists representing 23 countries. The questionnaire covers 7 themes: education and training including certification; staffing; typical tasks; professional organisations; resources; research and teaching; job satisfaction.ResultsAcross all surveys the response rate was >85% with the replies representing practice affecting more than half of the world’s population. The expectation of ROMP qualifications (MSc and between 1 and 3 years of clinical experience) has not changed much over the years.However, compared to 2008, the number of medical physicists in many countries has doubled. Formal professional certification is only available in a small number of countries. The number of experienced ROMPs is small in particular in low and middle income countries. The increase in staff numbers from 2008 to 2014 is matched by a similar increase in the number of treatment units which is accompanied by an increase in treatment complexity. Many ROMPs are required to work overtime and not many find time for research. Resource availability has only improved marginally and ROMPs still feel generally overworked, but professional recognition, while varying widely, appears to be improving slowly.ConclusionWhile number of physicists and complexity of treatment techniques and technologies have increased significantly, ROMP practice remains essentially unchanged over the last 6 years in the Asia Pacific Region.     

Developing a contextualised blended learning framework to enhance medical physics student learning and engagement

As a specialist field of study, medical physicists require a broad range of knowledge and skills to operate competently in their workplace. In Australia, these competencies are accredited by the Australasian College of Physical Scientists and Engineers in Medicine (ACPSEM). Education and training for medical physicists therefore consists of an exhaustive range of knowledge areas. This is made even more challenging due to the extremely diverse backgrounds of students in these specialist courses of study. These factors frequently lead to a disengagement by students with learning activities.To address some of these challenges, the Radiotherapy Physics unit in a Masters level Medical Physics course of study was re-designed to increase active learning that included scaffolded in-class and online tasks and supported by virtual reality simulations. These re-design initiatives were informed by a diverse team including academic and clinical medical physicists as well as education experts.A survey, conducted over two consecutive years was used to gain students perceptions about the re-design. The questions were designed to see if the students felt engaged with the various learning activities.Analysis of the survey data indicates that there was an overall improvement in students’ engagement with the learning activities and the learning content.The paper further discusses nuanced understanding about the ways in which students engaged with the various learning activities including online, in-class, practicals and industry attachments. The paper discusses the appropriately informed learning activities that can be used to improve student engagement for highly specialised, content heavy areas of study.     

A fast approach to identify trending articles in hot topics from XML based big bibliographic datasets

Nowadays XML based big bibliographic datasets are common in different domains which provide meta data about articles published in that domain. They have well defined tags which give details of the year, title, authors, abstract, keywords, the type of article, the venue of publishing the article and other such specific details about each article. A lot of statistics can be extracted from this dataset. Most of the time the tag pertaining to domain sub topic information associated with the article will be absent in the dataset as it is not an article attribute. Hence for such statistics articles must be mapped to its associated sub domain. This paper investigates this problem and proposes a fast approach to find trending articles and hot topics from XML based big bibliographic datasets. The proposed framework uses domain ontology to first classify articles into its sub topics. Fast detection of hot topics, trending keywords and articles is achieved using novel Map Reduce algorithms implemented on a hadoop distributed framework. Performance comparison demonstrates that it outperforms its non-Map Reduce counterpart in quickly sorting out the trending keywords and titles in a particular hot topic from XML based bibliographic dataset.     

A quantitative ranking of Canada's research output of original human studies for the decade 1989 to 1998

BACKGROUND: Since 1987 research articles have been catalogued with the author''s affiliation address in the 40 databases of the Medical Literature Analysis and Retrieval System (MEDLARS) of the National Library of Medicine, Bethesda, Md. The present study was conducted to examine the Canadian entries in MEDLARS to interpret past and future trends and to combine the MEDLARS demographic data with data from other sources to rank Canadian research output of human studies both nationally and internationally. METHODS: The PubMed Web site of the National Library of Medicine was used to count medical articles archived in MEDLARS and published from Jan. 1, 1989, through Dec. 31, 1998. The articles attributed to Canadian authors were compared by country, province, city, medical school, hospital, article type, journal and medical specialty. RESULTS: During the study period Canadian authors contributed on average 3% (standard deviation [SD] 0.2%) of the worldwide MEDLARS content each year, which translated to a mean of 11,067 (SD 1037) articles per year; 49% were human studies, of which 13% were clinical or controlled trials, and 55% involved people aged 18 years or less. In total, 68% of the articles were by authors affiliated with Canadian medical schools; those affiliated with the University of Toronto accounted for the greatest number (8604), whereas authors affiliated with McGill University had the greatest rate of annual increase in the quantity published (8%). Over one-third (38%) of the articles appeared in Canadian journals. When counted by specialty, 17% of the articles were by authors with clinical specialties, 5% by those with surgical specialties and 3% by those with laboratory specialties. INTERPRETATION: The annual rate of increase in research output for Canada was more than 3 times higher than that seen world wide. Canada is now ranked seventh among countries contributing human studies to MEDLARS. The increase indicates that Canada''s medical schools are productive, competitive in making contributions to medical science and are supporting Canadian journals.     

Bipolarization of Risk Perception about the Health Effects of Radiation in Residents after the Accident at Fukushima Nuclear Power Plant

The late health effects of low-dose rate radiation exposure are still a serious public concern in the Fukushima area even four years after the accident at Fukushima Daiichi Nuclear Power Plant (FNPP). To clarify the factors associated with residents’ risk perception of radiation exposure and consequent health effects, we conducted a survey among residents of Kawauchi village in May and June 2014, which is located within 30 km of FNPP. 85 of 285 residents (29.8%) answered that acute radiation syndrome might develop in residents after the accident, 154 (54.0%) residents responded that they had anxieties about the health effects of radiation on children, and 140 (49.1%) residents indicated that they had anxieties about the health effects of radiation on offspring. Furthermore, 107 (37.5%) residents answered that they had concerns about health effects that would appear in the general population simply by living in an environment with a 0.23 μSv per hour ambient dose for one year, 149 (52.2%) residents reported that they were reluctant to eat locally produced foods, and 164 (57.5%) residents believed that adverse health effects would occur in the general population by eating 100 Bq per kg of mushrooms every day for one year. The present study shows that a marked bipolarization of the risk perception about the health effects of radiation among residents could have a major impact on social well-being after the accident at FNPP.     

The TOPAS tool for particle simulation,a Monte Carlo simulation tool for physics,biology and clinical research

PurposeThis paper covers recent developments and applications of the TOPAS TOol for PArticle Simulation and presents the approaches used to disseminate TOPAS.Materials and methodsFundamental understanding of radiotherapy and imaging is greatly facilitated through accurate and detailed simulation of the passage of ionizing radiation through apparatus and into a patient using Monte Carlo (MC). TOPAS brings Geant4, a reliable, experimentally validated MC tool mainly developed for high energy physics, within easy reach of medical physicists, radiobiologists and clinicians. Requiring no programming knowledge, TOPAS provides all of the flexibility of Geant4.ResultsAfter 5 years of development followed by its initial release, TOPAS was subsequently expanded from its focus on proton therapy physics to incorporate radiobiology modeling. Next, in 2018, the developers expanded their user support and code maintenance as well as the scope of TOPAS towards supporting X-ray and electron therapy and medical imaging. Improvements have been achieved in user enhancement through software engineering and a graphical user interface, calculational efficiency, validation through experimental benchmarks and QA measurements, and either newly available or recently published applications. A large and rapidly increasing user base demonstrates success in our approach to dissemination of this uniquely accessible and flexible MC research tool.ConclusionsThe TOPAS developers continue to make strides in addressing the needs of the medical community in applications of ionizing radiation to medicine, creating the only fully integrated platform for four-dimensional simulation of all forms of radiotherapy and imaging with ionizing radiation, with a design that promotes inter-institutional collaboration.     

Priority list of research areas for radiological nuclear threat countermeasures

To help the nation prepare for the possibility of a terrorist attack using radiological and nuclear devices, the Office of Science and Technology Policy and the Homeland Security Council established an interagency working group. The working group deliberated on the research needs for radiological/ nuclear threat countermeasures and identified and prioritized 18 areas for further attention. The highest priorities were given to research on (1) radioprotectors for use prior to exposure; (2) therapeutic agents for postexposure treatment; (3) antimicrobial therapy for infections associated with radiation exposure; (4) cytokines and growth factors; (5) mechanisms of radiation injury at the molecular, cellular, tissue and organism levels; and (6) automation of biodosimetric assays. High priority was given to (1) developing biomarkers for biodosimetry; (2) enhancing training in the radiation sciences; (3) exploring the consequences of combined injury; (4) establishing a repository of information regarding investigational countermeasures; and (5) following the health of an exposed population to better prepare for subsequent events. The research areas that the committee felt required the attention of the radiation research community are described in this report in an effort to inform this community about the needs of the nation and to encourage researchers to address these critical issues.     

User requirements on CT-based computed dose planning systems in radiation therapy. Presentation of 'check lists'

The expanding use of computers in radiation therapy procedures, especially the rapidly increasing use of digital CT-information, necessitates the coordination of the different systems in order to facilitate their developments. In order to define necessary demands for tomorrow a Nordic cooperation was initiated 1981 by NORDFORSK (Nordic co-operative organization for applied research), and a group of physicians and physicists having their daily work in this field of medicine and physics was invited to produce a report on 'User requirements on CT-based computed dose planning systems on radiation therapy'. The work has been done within the frame of NORDFORSK's activities and has been independent of the existing commissions and associations in the radiology field, but it has taken into consideration recommendations that have been given by or are being produced by other organizations. This report is a short summary of the complete paper which will be published in Acta Radiologica. The aim of this short version is to get an early presentation of the 'requirement lists' (see Appendix) which we think are of immediate importance.     

Evaluation of medical physics training in radiology residency in 67 countries

PurposeThe main aim of medical physics training in radiology residency is to have appropriate and safer imaging of patients and safety of personnel. The need to have adequate coverage of medical physics and radiation safety in curricula of radiology residency is well perceived, but it is not known how far it is implemented in practice.MethodsWe have analysed the data from 67 countries on medical physics teaching and assessment of residents in radiology programs, considering differences between countries in function of their human development index (HDI).ResultsThe results indicate that teaching of medical physics by radiologists rather than by medical physicists is very common and there is relationship with the developmental status of a country. The majority of countries with very high HDI used a written test (69%) for medical physics topics, often in combination with other subjects (63%). Further, there is lack of direct involvement of medical physicists during the examination phase of residents. Geographically, it can be seen that Latin American countries in particular lack involvement of medical physicists during both the teaching and examination phase.ConclusionThe lack of adequate involvement of medical physicists in training and in the formal examination of radiology residents in both developed and developing countries is a matter of concern with likely implications on patient and staff safety.