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Purpose: Task Group 121 – Effects of ionizing radiation exposure in offspring and next generations – is a task group under the Committee 1 of the International Commission on Radiological Protection (ICRP), approved by the Main Commission on 18th November 2021. The main goals of Task Group 121 are to (1) review and update the scientific literature of relevance to radiation-related effects in the offspring of parent(s) exposed to ionizing radiation in both human and non-human biota; (2) to assess preconceptional and intrauterine effects of radiation exposure and related morbidity and mortality; and, (3) to provide advice about the level of evidence and how to consider these preconceptional and postconceptional effects in the system of radiological protection for humans and non-human biota. Methods: The Task Group is reviewing relevant literature since Publication 90 'Biological effects after prenatal irradiation (embryo and fetus)' (2003) and will include radiation-related effects on future generations in humans, animals, and plants. This review will be conducted to account for the health effects on offspring and subsequent generations in the current system of radiological protection. Radiation detriment calculation will also be reviewed. Finally, preliminary recommendations will be made to update the integration of health effects in offspring and next generations in the system of radiological protection. Results: A Workshop, jointly organized by ICRP Task Group 121 and European Radiation Protection Research Platforms MELODI and ALLIANCE was held in Budapest, Hungary, from 31st May to 2nd June 2022. Participants discussed four important topics: (1) hereditary and epigenetic effects due to exposure of the germ cell line (preconceptional exposure), (2) effects arising from exposure of the embryo and fetus (intrauterine exposure), (3) transgenerational effects on biota, and (4) its potential impact on the system of radiological protection. Conclusions: Based on the discussions and presentations during the breakout sessions, newer publications, and gaps on the current scientific literature were identified. For instance, there are some ongoing systematic reviews and radiation epidemiology reviews of intrauterine effects. There are newer methods of Monte Carlo simulation for fetal dosimetry, and advances in radiation genetics, epigenetics, and radiobiology studies. While the current impact of hereditary effects on the global detriment was reported as small, the questions surrounding the effects of radiation exposure on offspring and the next generation are crucial, recurring, and with a major focus on exposed populations. This article summarizes the workshop discussions, presentations, and conclusions of each topic and introduces the special issue of the International Journal of Radiation Biology resulting from the discussions of the meeting. [ABSTRACT FROM AUTHOR]

A Task Group (TG121) of the International Commission on Radiological Protection (ICRP) Committee 1 was launched in 2021 to study the effects of ionizing radiation in offspring and next generations. In this report, we summarize the evidence of multi- and trans-generational effects in non-human biota species that was discussed at the ICRP workshop entitled "Effects of Ionizing Radiation Exposure in Offspring and Next Generations" in June 2022. Epigenetic changes, including changes in DNA methylation, have been observed in trans- and multi-generational irradiation studies in both plants and animals. There were also reports of changes in offspring survival and reproduction. The reported evidence for altered reproduction is an area of potential concern, due to possible effects at the population or ecosystem level. Different considerations are also discussed regarding non-human biota data, such as transferability of data between different species or extending knowledge to humans, differences in species radiosensitivity, the presence of adaptive responses, and dose reconstruction for exposures that occur across multiple generations. Overall, there is a diverse range of available data of the effects in non-human biota, and it will require careful consideration when incorporating this evidence into the system of radiological protection of humans and of the environment. [ABSTRACT FROM AUTHOR]

Purpose: Our aim was to evaluate whether mitochondrial DNA (mtDNA) damage in hair bulbs could be a suitable biomarker for the detection of local exposure to ionizing radiation. Materials and methods: Mouse hair was collected 4 and 24 hours, 3 and 10 days after single whole-body exposure to 0, 0.1, and 2 Gy radiation. Pubic hair (treated area) and scalp hair (control area) were collected from 13 prostate cancer patients before and after fractioned radiotherapy with an average total dose of 2.7 Gy to follicles after five fractions. Unspecified lesion frequency of mtDNA was analyzed with long PCR, large mtDNA deletion levels were tested with real-time PCR. Results: Unspecified lesion frequency of mtDNA significantly increased in mouse hair 24 hours after irradiation with 2 Gy, but variance among samples was high. No increase in lesion frequency could be detected after 0.1 Gy irradiation. In prostate cancer patients, there was no significant change in either the unspecified lesion frequency or in the proportion of 4934-bp deleted mtDNA in pubic hair after radiotherapy. The proportions of murine 3860-bp common deletion, human 4977-bp common deletion and 7455-bp deleted mtDNA were too low to be analyzed reliably. Conclusions: Our results suggest that the unspecified lesion frequency and proportion of large deletions of mtDNA in hair bulbs are not suitable biomarkers of exposure to ionizing radiation. [ABSTRACT FROM AUTHOR]

Purpose: To summarize existing knowledge and to understand individual response to radiation exposure, the MELODI Association together with CONCERT European Joint Programme has organized a workshop in March 2018 on radiation sensitivity and susceptibility. Methods: The workshop reviewed the current evidence on this matter, to inform the MELODI Strategic Research Agenda (SRA), to determine social and scientific needs and to come up with recommendations for suitable and feasible future research initiatives to be taken for the benefit of an improved medical diagnosis and treatment as well as for radiation protection. Results: The present paper gives an overview of the current evidence in this field, including potential effect modifiers such as age, gender, genetic profile, and health status of the exposed population, based on clinical and epidemiological observations. Conclusion: The authors conclude with the following recommendations for the way forward in radiation research: (a) there is need for large (prospective) cohort studies; (b) build upon existing radiation research cohorts; (c) use data from well-defined cohorts with good exposure assessment and biological material already collected; (d) focus on study quality with standardized data collection and reporting; (e) improve statistical analysis; (f) cooperation between radiobiology and epidemiology; and (g) take consequences of radiosensitivity and radiosusceptibility into account. [ABSTRACT FROM AUTHOR]

Purpose: The workshop on 'Individual Radiosensitivity and Radiosusceptibility' organized by MELODI and CONCERT on Malta in 2018, evaluated the current state of assays to identify sensitive and susceptible subgroups. The authors provide an overview on potential screening assays detecting individuals showing moderate to severe early and late radiation reactions or are at increased risk to develop cancer upon radiation exposure. Conclusion: It is necessary to separate clearly between tissue reactions and stochastic effects such as cancer when comparing the existing literature to validate various test systems. Requirements for the assays are set up. The literature is reviewed for assays that are reliable and robust. Sensitivity and specificity of the assays are regarded and scrutinized for modifying factors. Accuracy of an assay system is required to be more than 90% to balance risks of adverse reactions against risk to fail to cure the cancer. No assay/biomarker is in routine use. Assays that have shown predictive potential for radiosensitivity include SNPs, the RILA assay, and the pATM assay. A tree of risk guideline for radiologists is provided to assist medical treatment decisions. Recommendations for effective research include the setup of common retrospective and prospective cohorts/biobanks to validate current and future tests. [ABSTRACT FROM AUTHOR]