Toward a consensus on radiobiology teaching to radiation oncology residents

There are approximately 82 radiation oncology residency programs in the United States, which provide training opportunities for about 400 residents. All accredited radiation oncology residency programs must have at least one basic scientist on the faculty, and it is these individuals who often assume, wholly or in part, the responsibility of teaching radiation and cancer biology to radiation oncology residents in preparation for the American College of Radiology (ACR) In-Training Examination in Radiation Oncology and the American Board of Radiology (ABR) written examinations. In response to a perceived lack of uniformity in radiation and cancer biology curricula currently being taught to residents and a perceived lack of guidance for instructors in formulating course content for this population, a special session was presented at the Forty-eighth Annual Radiation Research Society meeting on April 23, 2001. The session, entitled "Toward a Consensus on Radiobiology Teaching to Radiation Oncology Residents", was focused on issues related to teaching radiobiology to radiation oncology residents and targeted for individuals who actively teach radiation and cancer biology as well as coordinators of residency training programs. The speakers addressed current challenges and future problems facing instructors and programs. Among these were lack of feedback on resident performance on ABR and ACR written examinations and on course content, uncertainty about what topics residents must know to pass the ABR examination, and, in the near future, a reduction (due to retirement) of instructors qualified to teach radiobiology. This article provides a synopsis of the information that was presented during that session, offers a glimpse into how the ABR and ACR examinations are prepared and details of the content of past and future examinations, and summarizes the activities of the Joint Working Group on Radiobiology Teaching which was formed to educate instructors, to establish a consensus for course curricula, and to improve the overall quality of resident teaching.     

Education and training for radiation scientists: radiation research program and American Society of Therapeutic Radiology and Oncology Workshop, Bethesda, Maryland, May 12-14, 2003

Current and potential shortfalls in the number of radiation scientists stand in sharp contrast to the emerging scientific opportunities and the need for new knowledge to address issues of cancer survivorship and radiological and nuclear terrorism. In response to these challenges, workshops organized by the Radiation Research Program (RRP), National Cancer Institute (NCI) (Radiat. Res. 157, 204-223, 2002; Radiat. Res. 159, 812-834, 2003), and National Institute of Allergy and Infectious Diseases (NIAID) (Nature, 421, 787, 2003) have engaged experts from a range of federal agencies, academia and industry. This workshop, Education and Training for Radiation Scientists, addressed the need to establish a sustainable pool of expertise and talent for a wide range of activities and careers related to radiation biology, oncology and epidemiology. Although fundamental radiation chemistry and physics are also critical to radiation sciences, this workshop did not address workforce needs in these areas. The recommendations include: (1) Establish a National Council of Radiation Sciences to develop a strategy for increasing the number of radiation scientists. The strategy includes NIH training grants, interagency cooperation, interinstitutional collaboration among universities, and active involvement of all stakeholders. (2) Create new and expanded training programs with sustained funding. These may take the form of regional Centers of Excellence for Radiation Sciences. (3) Continue and broaden educational efforts of the American Society for Therapeutic Radiology and Oncology (ASTRO), the American Association for Cancer Research (AACR), the Radiological Society of North America (RSNA), and the Radiation Research Society (RRS). (4) Foster education and training in the radiation sciences for the range of career opportunities including radiation oncology, radiation biology, radiation epidemiology, radiation safety, health/government policy, and industrial research. (5) Educate other scientists and the general public on the quantitative, basic, molecular, translational and applied aspects of radiation sciences.     

Global radiation oncology waybill

Background/aim

Radiation oncology covers many different fields of knowledge and skills. Indeed, this medical specialty links physics, biology, research, and formation as well as surgical and clinical procedures and even rehabilitation and aesthetics. The current socio-economic situation and professional competences affect the development and future or this specialty. The aim of this article was to analyze and highlight the underlying pillars and foundations of radiation oncology, indicating the steps implicated in the future developments or competences of each.

Methods

This study has collected data from the literature and includes highlights from discussions carried out during the XVII Congress of the Spanish Society of Radiation Oncology (SEOR) held in Vigo in June, 2013. Most of the aspects and domains of radiation oncology were analyzed, achieving recommendations for the many skills and knowledge related to physics, biology, research, and formation as well as surgical and clinical procedures and even supportive care and management.

Results

Considering the data from the literature and the discussions of the XVII SEOR Meeting, the “waybill” for the forthcoming years has been described in this article including all the aspects related to the needs of radiation oncology.

Conclusions

Professional competences affect the development and future of this specialty. All the types of radio-modulation are competences of radiation oncologists. On the other hand, the pillars of Radiation Oncology are based on experience and research in every area of Radiation Oncology.     

Cancer as an emergent phenomenon in systems radiation biology

Radiation-induced DNA damage elicits dramatic cell signaling transitions, some of which are directed towards deciding the fate of that particular cell, while others lead to signaling to other cells. Each irradiated cell type and tissue has a characteristic pattern of radiation-induced gene expression, distinct from that of the unirradiated tissue and different from that of other irradiated tissues. It is the sum of such events, highly modulated by genotype that sometimes leads to cancer. The challenge is to determine as to which of these phenomena have persistent effect that should be incorporated into models of how radiation increases the risk of developing cancer. The application of systems biology to radiation effects may help to identify which biological responses are significant players in radiation carcinogenesis. In contrast to the radiation biology paradigm that focuses on genomic changes, systems biology seeks to integrate responses at multiple scales (e.g. molecular, cellular, organ, and organism). A key property of a system is that some phenomenon emerges as a property of the system rather than of the parts. Here, the idea that cancer in an organism can be considered as an emergent phenomenon of a perturbed system is discussed. Given the current research goal to determine the consequences of high and low radiation exposures, broadening the scope of radiation studies to include systems biology concepts should benefit risk modeling of radiation carcinogenesis. Presented at the First International Workshop on Systems Radiation Biology, February 14–16 2007, GSF-Research Centre, Neuherberg, Germany.     

New perspectives in radiation oncology: Young radiation oncologist point of view and challenges

AimTo assess the role of the young radiation oncologist in the context of important recent advancements in the field of radiation oncology, and to explore new perspectives and competencies of the young radiation oncologist.BackgroundRadiation oncology is a field that has rapidly advanced over the last century. It holds a rich tradition of clinical care and evidence-based practice, and more recently has advanced with revolutionary innovations in technology and computer science, as well as pharmacology and molecular biology.Materials and methodsSeveral young radiation oncologists from different countries evaluated the current status and future directions of radiation oncology.ResultsFor young radiation oncologists, it is important to reflect on the current practice and future directions of the specialty as it relates to the role of the radiation oncologist in the comprehensive management of cancer patients. Radiation oncologists are responsible for the radiation treatment provided to patients and its subsequent impact on patients’ quality of life. Young radiation oncologists must proactively master new clinical, biological and technical information, as well as lead radiation oncology teams consisting of physicists, dosimetrists, nurses and technicians.ConclusionsThe role of the young radiation oncologist in the field of oncology should be proactive in developing new competencies. Above all, it is important to remember that we are dealing with the family members and loved ones of many individuals during the most difficult part of their lives.     

Roles of stem cells in tissue turnover and radiation carcinogenesis

Radiation research has its foundation on the target and hit theories, which assume that the initial stochastic deposition of energy on a sensitive target in a cell determines the final biological outcome. This assumption is rather static in nature but forms the foundation of the linear no-threshold (LNT) model of radiation carcinogenesis. The stochastic treatment of radiation carcinogenesis by the LNT model enables easy calculation of radiation risk, and this has made the LNT model an indispensable tool for radiation protection. However, the LNT model sometimes fails to explain some of the biological and epidemiological data, and this suggests the need for insight into the mechanisms of radiation carcinogenesis. Recent studies have identified unique characteristics of the tissue stem cells and their roles in tissue turnover. In the present report, some important issues of radiation protection such as the risk of low-dose-rate exposures and in utero exposures are discussed in light of the recent advances of stem cell biology.     

The IRI-DICE hypothesis: ionizing radiation-induced DSBs may have a functional role for non-deterministic responses at low doses

Radiation and Environmental Biophysics - Low-dose ionizing radiation (IR) responses remain an unresolved issue in radiation biology and risk assessment. Accurate knowledge of low-dose responses is...     

Estimates of relative risks for cancers in a population after prolonged low-dose-rate radiation exposure: a follow-up assessment from 1983 to 2005

Radiation effects on cancer risks in a cohort of Taiwanese residents who received protracted low-dose-rate gamma-radiation exposures from (60)Co-contaminated reinforcing steel used to build their apartments were studied, and risks were compared to those in other radiation-exposed cohorts. Analyses were based on a more extended follow-up of the cohort population in which 117 cancer cases diagnosed between 1983 and 2005 among 6,242 people with an average excess cumulative exposure estimate of about 48 mGy. Cases were identified from Taiwan's National Cancer Registry. Radiation effects on cancer risk were estimated using proportional hazards models and were summarized in terms of the hazard ratio associated with a 100-mGy increase in dose (HR(100mGy)). A significant radiation risk was observed for leukemia excluding chronic lymphocytic leukemia (HR(100mGy) 1.19, 90% CI 1.01-1.31). Breast cancer exhibited a marginally significant dose response (HR(100mGy) 1.12, 90% CI 0.99-1.21). The results further strengthen the association between protracted low-dose radiation and cancer risks, especially for breast cancers and leukemia, in this unique cohort population.     

The radiation hybrid database.

Since July 1995, the European Bioinformatics Institute (EBI) has maintained the Radiation Hybrid database (RHdb; http://www.ebi.ac. uk/RHdb ), a public database for radiation hybrid data. Radiation hybrid mapping is an important technique for determining high resolution maps. Recently, CORBA access has been added to RHdb. The EBI is an Outstation of the European Molecular Biology Laboratory (EMBL).     

Advances of radiation sterilisation in tissue banking

Under the auspices of the IAEA tissue banking programme on “Radiation Sterilisation of Tissue Graft” conducted from 1985 to 2004, many scientists and surgeons were involved in various regional research and development (R&D) projects mainly in dealing with radiation dose selection, radiation effects on human tissues and quality system in radiation sterilisation. New findings on radiation effects, tissue processing and preservation were shared during the regional and interregional meetings and workshops. Many tissue banks started to use radiation (25 kGy) to sterilize tissue grafts for tissue safety and efficacy and still continue to use it. The IAEA Code of Practice for Radiation Sterilization of Tissues Allografts developed in 2007 offered simpler methods to conduct radiation dose setting and dose validation experiments for tissue grafts. Advances in dose selection and dose mapping are continued under the quality management system when banks need to be certified to continue their operation. The combination of good tissue processing and preservation as well as good radiation practice will ensure the tissue products are properly sterilised thus safe and of high quality. Experience in meeting challenges in using radiation sterilisation and achievements reported by the tissue bankers are shared here.     

Radiation scientists and homeland security

Radiation scientists represent an important resource in homeland defense. Security analysts worry that a crude but deadly radiological bomb might be fashioned from stolen nuclear material and a few sticks of dynamite. Such a device could kill dozens, hundreds, and possibly thousands and could contaminate a square mile or more. Emergency workers may call upon radiation scientists to aid the injured. Educational materials are available on the ACR, ASTRO, and RRS websites, linked to the Armed Forces Radiobiology Research Institute and the Oak Ridge National Laboratory, to provide radiation workers material that they can use to help emergency room and civil defense personnel after a terrorist attack. Radiation scientists are urged to obtain these materials and contact their local hospital and public health authorities to volunteer their services and expertise.     

Analysis of pre-residency research productivity,dual degree status,and gender distribution of underrepresented minorities among a current United States radiation oncology junior resident class

BackgroundAmong the most competitive medical subspecialties, representation of underrepresented minorities (African–American race and/or Hispanic ethnicity) among resident trainees has historically been low compared to their United States Census general population representation. Research productivity and dual degree status may impact residency applicant competitiveness. To date, such an analysis has yet to be performed in Radiation Oncology.MethodsA list of radiation oncology residents from the graduating class of 2022 was obtained through internet searches. Demographics included were gender and dual degree status. Research productivity was calculated using the number of pre-residency peer-reviewed publications (PRP). Fisher's exact test was used for statistical analysis.ResultsOf the 179 residents evaluated from the 2022 class, eleven (6.1%) were underrepresented minorities. Compared to the remainder of the class, underrepresented minorities had a lower proportion of men (63.6% versus 69.3%), a higher proportion of dual degrees (45.5% versus 28.6%), and a lower proportion of MD-PhD degrees (9.1% versus 17.2%). Underrepresented minorities had a higher proportion of residents with at least two PRP (72.7% versus 57.1%) and a lower proportion of residents with no PRP (18.2% versus 24.4%). None of these differences reached statistical significance (p > 0.05).ConclusionUnderrepresented minorities were comparable to the remainder of their Radiation Oncology resident class regarding gender distribution, dual degrees status, and likelihood of having at least two peer-reviewed publications cited in PubMed during the calendar year of residency application. Further studies will be needed to determine how these findings translate into future scholarly activity and post-graduate career choice.     

Organ doses from radiation therapy in atomic bomb survivors

Previous surveys of radiation therapy among the Life Span Study (LSS) population at the Radiation Effects Research Foundation (RERF) revealed that 1,670 (1.4%) of the LSS participants received radiation treatments before 1984. The data on therapeutic radiation doses are indispensable for studying the relationship between radiation treatments and subsequent cancer occurrences. In this study, the radiation treatments were reproduced experimentally to determine the scattered radiation doses. The experiments were conducted using a female human phantom and various radiation sources, including a medium-voltage X-ray machine and a (60)Co gamma-ray source. Doses were measured using thermoluminescence dosimetry and ionization chambers. Radiation doses were determined for the salivary glands, thyroid gland, breast, lung, stomach, colon, ovary and active bone marrow. The results have been used for documenting the organ doses received by patients in previous surveys. The contribution of therapeutic irradiation to the occurrence of chromosome aberrations was studied using data on doses to active bone marrow from both radiation treatments and atomic bomb exposures in 26 RERF Adult Health Study participants. The results suggest that radiation treatments contributed to a large part of their frequencies of stable-type chromosome aberrations. The therapeutic radiation doses determined in the present study are available for investigating the effects of therapeutic irradiation on the subsequent primary cancers among atomic bomb survivors who received radiation treatments.     

Cobalt-60 gamma radiation increased the nitric oxide generation in cultured rat vascular smooth muscle cells

Radiation is a promising and new treatment for restenosis following angioplasty. Nitric oxide has been proposed as a potential "anti-restenotic" molecule. We radiated the cultured rat vascular smooth muscle cells with Cobalt-60 gamma radiation at doses of 14 and 25Gy and observed nitrite production, cGMP content, L-arginine uptake, inducible nitric oxide synthase (iNOS) activity, and the gene expression of iNOS. Results showed that radiation at doses of 14 and 25Gy increased cGMP content by 92.4% and 86.4%, respectively. Radiation at the dose of 25Gy increased the iNOS activity and nitrite content, but radiation at the dose of 14Gy had no significant effect on iNOS activity and NO production. Both doses of radiation significantly decreased the L-arginine transport. Radiation at the doses of 14 and 25Gy increased iNOS gene expression significantly, which was consistent with the effect of radiation on iNOS activity. In conclusion, radiation induces the NO generation by up-regulating the iNOS activity.     

Iron-ion radiation accelerates atherosclerosis in apolipoprotein E-deficient mice

Radiation exposure from a number of terrestrial sources is associated with an increased risk for atherosclerosis. Recently, concern over whether exposure to cosmic radiation might pose a similar risk for astronauts has increased. To address this question, we examined the effect of 2 to 5 Gy iron ions ((56)Fe), a particularly damaging component of cosmic radiation, targeted to specific arterial sites in male apolipoprotein E-deficient (apoE(-/-)) mice. Radiation accelerated the development of atherosclerosis in irradiated portions of the aorta independent of any systemic effects on plasma lipid profiles or circulating leukocytes. Further, radiation exposure resulted in a more rapid progression of advanced aortic root lesions, characterized by larger necrotic cores associated with greater numbers of apoptotic macrophages and reduced lesional collagen compared to sham-treated mice. Intima media thickening of the carotid arteries was also exacerbated. Exposure to (56)Fe ions can therefore accelerate the development of atherosclerotic lesions and promote their progression to an advanced stage characterized by compositional changes indicative of increased thrombogenicity and instability. We conclude that the potential consequences of radiation exposure for astronauts on prolonged deep-space missions are a major concern. Knowledge gained from further studies with animal models should lead to a better understanding of the pathophysiological effects of accelerated ion radiation to better estimate atherogenic risk and develop appropriate countermeasures to mitigate its damaging effects.     

A microdosimetric understanding of low-dose radiation effects

This paper presents a microdosimetric approach to the problem of radiation response by which effects produced at low doses and dose rates can be understood as the consequences of radiation absorption events in the nucleus of a single relevant cell and in its DNA. Radiation absorption at the cellular level, i.e. in the cell nucleus as a whole, is believed to act through radicals. This kind of action is called 'non-specific' and leads to the definition of an 'elemental dose' and the 'integral response probability' of a cell population. Radiation absorption at the molecular level, i.e. in sensitive parts of the DNA, is thought to act through double-strand breaks. This kind of action is called 'specific' and leads to a 'relative local efficiency'. In general, both mechanisms occur for all types of radiation; however, it is the dose contribution of both specific and non-specific effects that determines the radiation quality of a given radiation. The implications of this approach for the specification of low-dose and low dose-rate regions are discussed.     

RHdb: the radiation hybrid database

Since July 1995, the European Bioinformatics Institute (EBI) has maintained RHdb (http://www.ebi.ac.uk/RHdb ), a public database for radiation hybrid data. Radiation hybrid mapping is an important technique for determining high resolution maps. RHdb is also served by CORBA servers. The EBI is an Outstation of the European Molecular Biology Laboratory (EMBL).     

Correlation of intensity-modulated radiation therapy at a specific radiation dose with the prognosis of nasal mucous damage after radiotherapy

Radiation and Environmental Biophysics - Objective of the present study was to investigate the tolerant radiation dose of nasal mucosa by observing and analyzing patients who received...     

Failla memorial lecture. Risk, research, and radiation protection

Radiation protection concerns the risk of stochastic late effects, especially cancer, and limits on radiation exposure both occupationally and for the public tend to be based on these risks. The risks are determined, mainly by expert committees, from the steadily growing information on exposed human populations, especially the survivors of the atomic bombs dropped in Japan in 1945. Risks of cancer estimated up to the early 1980s were in the range 1 to 5 X 10(-2)/Sv, but recent revisions in the dosimetry of the Japanese survivors and additional cycles of epidemiological information suggest values now probably at the high end of this range. These are likely to require an increase in the values used for radiation protection. A major problem with risk estimation is that data are available only for substantial doses and must be extrapolated down to the low-dose region of interest in radiation protection. Thus the shape of the dose-response curve is important, and here we must turn to laboratory research. Of importance are studies involving (1) dose rate, which affects the response to low-LET radiation and often to high-LET radiation as well; (2) radiation quality, since the shapes of the dose-response curves for high- and low-LET radiation differ and thus the RBE, the ratio between them, varies, reaching a maximum value RBEM at low doses; and (3) modifiers of the carcinogenic response, which either enhance or reduce the effect of a given dose. Radiation protection depends both on risk information, and especially also on comparisons with other occupational and public risks, and on research, not only for extrapolations of risk to low doses but also in areas where human information is lacking such as in the effects of radiation quality and in modifications of response.