ICRP 2019 Abstracts

Keynote Speaker - Bo Lindell Medal for the Promotion of Radiological Protection Recipient

Interdisciplinary radiation protection research in support of medical uses of ionising radiation

E. A. Ainsbury

Public Health England Centre for Radiation, Chemical and Environmental Hazards, Chilton, Didcot, Oxford OX11 0RQ, UK. liz.ainsbury@phe.gov.uk

Medical exposures form the largest manmade contributor to total ionising radiation exposure of the UK population, for example, and in recent years, new technologies have been developed to improve treatment and prognosis of individuals treated with radiation for diseases such as cancer. However, there is evidence of public, patient and medical professional concern that radiation protection regulations and practices, as well as understanding of potential long term adverse health effects of radiation exposure (in the context of other health risks), have not always 'kept pace' with technological developments in this field.

The 'Radiation Theme' of the PHE and Newcastle University Health Protection Research Unit project 'Chemical and Radiation Threats and Hazards' is focused on addressing this need, through a genuinely interdisciplinary approach bringing together world leading epidemiologists, radiation biologists, clinicians, statisticians and artists - through a strong grounding in public, patient and medical professional involvement in research. Similarly, the EU CONCERT funded LDLensRad project seeks to understand the mechanisms of action of low dose ionising radiation in the lens, and the potential contribution to initiation or promotion of cataract.

Recent outputs from these consortia include publications on new conclusions regarding risk following CT exposure and cardiac catheterisation, data of relevance to the reduced eye dose limits in the recently revised UK Ionising Radiation Regulations, and further development towards use of biological endpoints that can be used as markers of radiation risk to support personalised use of radiation in medicine. The current status of understanding based on this and other recent work will be presented, to highlight the value of genuinely interdisciplinary work in this important field.

Acknowledgements: The work was partly supported by the National Institute for Health Research Health Protection Research Unit (NIHR HPRU) in Chemical & Radiation Threats & Hazards at Newcastle University in partnership with Public Health England (PHE). The views expressed are those of the authors and not necessarily those of the NIHR, the Department of Health or PHE. The LDLensRad project has received funding from the Euratom research and training programme 2014-2018 in the framework of the CONCERT [grant agreement No 662287]. The author wishes to acknowledge a large number of international collaborators, but in particular the fundamental contributions of all partners of the HPRU and LDLensRad projects, without whom this work would not have been possible.

Session 6.1 Radon in Mining and Beyond

Miner studies and radiological protection against radon

D. Laurier

Institute for Radiological Protection and Nuclear Safety, Health and Environment Division. IRSN/PSE-Sante/SESANE, BP 17, 92262 Fontenay aux Roses Cedex, France dominique.laurier@irsn.fr

Uranium mining began in the late 1940s. Mining conditions have changed radically over time, with improved working conditions, the introduction of forced ventilation and the implementation of radiological protection measures from the late 1950s onwards. The first epidemiological cohorts of miners began to be assembled in the 1960’s. In 1993, ICRP Publication 65 estimated the risk of lung cancer mortality from radon exposure from seven cohorts, involving more than 31,000 miners. In 1999, the BEIR VI report provided a comprehensive analysis of 11 cohorts, including more than 60,000 miners. The German Wismut uranium miners' cohort, comprising more than 60,000 miners, was assembled in the late 1990s. In total, about 15 studies have been conducted worldwide. These studies have had a significant influence on the understanding of radon risks and have helped to establish that radon is carcinogenic to human lungs. They provided a quantitative basis for estimating the excess risk of lung cancer associated with radon, taking into account factors that modify the exposure-risk relationship such as age, time since exposure or exposure rate. Analysis of available smoking data sets revealed that the relationship between lung cancer mortality and radon exposure persisted when smoking habits were taken into account. Current results do not show an association between radon and any health risk other than lung cancer. Concentrations of radon progeny in the first underground mines were several orders of magnitude higher than what is commonly encountered today. For the purposes of radiological protection today, the most relevant studies on miners are those with low cumulative exposure levels, long duration of follow-up and good quality data. Recent literature reviews, carried out by the ICRP in 2010 or more recently by UNSCEAR in 2019, show that such studies generally show a significant association between cumulative radon exposure and lung cancer mortality at low exposure levels, with a higher risk coefficient than estimated from studies based on miners exposed in the early years. In addition, lung cancer risk estimates from these low-exposed miners are of similar magnitude as those from indoor radon studies. According to the results of epidemiological studies conducted from low-exposed miners, the lifetime excess absolute risk estimated in 2010 in ICRP Publication 115 was about twice as high as that obtained in 1993 in ICRP Publication 65. These estimates of lifetime risk are consistent with the new derived dose conversion coefficients for radon using ICRP biokinetic and dosimetric models, published in 2017 in ICRP Publication 137. Most recently, the PUMA (Pooled Uranium Miner Analysis) study was launched, including data from more than 120,000 miners from the main epidemiological studies of uranium miners worldwide. This international study will improve our understanding of radon-related diseases and strengthen the basis for radon radiological protection.

ICRP Recommendations on Radon

J.D. Harrison

Public Health England, Centre for Radiation, Chemical and Environmental Hazards, Chilton, Didcot, Oxon OX11 0RQ, UK. Oxford Brookes University, Faculty of Health and Life Sciences, Oxford OX3 0BP, UK. john.harrison@phe.gov.uk

ICRP publishes guidance on protection from radon in workplaces and homes and dose coefficients for use in assessments of exposure for protection purposes. Publication 126 recommends an upper reference level for exposures in most workplaces and homes of 300 Bq m-3. In most circumstances, protection can be optimised using measurements of air concentrations directly without considering radiation doses. However, dose estimates are required for workers when radon is considered as occupational exposure (eg. in mines) and for higher exposures in other workplaces (eg. offices) when the reference level is exceeded persistently. Publication 137 recommends a dose coefficient of 3 mSv per mJ h m-3 (approximately 10 mSv per WLM) for most circumstances of exposure in workplaces, equivalent to 6.7 nSv per Bq h m-3 using an equilibrium factor of 0.4 (16.8 nSv per Bq h m-3 EEC). Using this dose coefficient, annual exposure of workers to 300 Bq m-3 corresponds to 4 mSv. For comparison, using the same coefficient for exposures in homes corresponds to 14 mSv. If circumstances of occupational exposure warrant more detailed consideration and reliable alternative data are available, site-specific doses can be assessed using methodology provided in Publication 137.

Australian Action to Reduce Health Risks from Radon

S.A. Long and R.A. Tinker

Australian Radiation Protection and Nuclear Safety Agency, 619 Lower Plenty Road, Yallambie, 3085; e-mail: Stephen.long@arpansa.gov.au; Rick.Tinker@arpansa.gov.au

In Australia worker exposure to radon in underground uranium mines has been a focus of policy makers and regulators, and has been well controlled in the industry sector. That cannot be said for public exposure to radon. Radon exposure studies in the late 1980’s and early 1990’s demonstrated that the levels of radon in Australian and New Zealand homes were some of the lowest in the world. The International Basic Safety Standards, published by the International Atomic Energy Agency (IAEA), requires the government to establish and implement an action plan for controlling public exposure due to radon indoors. To assist countries, the World Health Organization (WHO) provides options on radon health risk reduction and sound policy options for prevention and mitigation of radon. Globally there many examples of efforts to act on this information and to reduce the number of lung cancers related to radon exposures. When considering different policy options it is important to develop radon prevention and mitigation programmes reflecting elements that are unique to your region or country. The Australian Radon Action Plan is being considered at a national level and presents a long-range strategy designed to reduce the radon-induced lung cancer in Australia as well as the individual risk for people living with high radon concentrations. In Australia, workers who are not currently designated as occupationally exposed are also considered members of the public. In the Australian context, there are only a limited set of scenarios that might give rise to sufficiently high enough radon concentrations that warrant mitigation. These include highly energy efficient buildings in areas of high radon potential, underground workplaces, workplaces with elevated radon concentrations, such as spas using natural spring waters, or enclosed workspaces with limited ventilation. Guided by the Plan the risk posed by radon in Australia will be minimised by taking action in the key areas of raising awareness and encouraging action, assessing workplaces and public buildings that may have elevated radon concentrations, providing advice and guidance to those workplaces and public areas that have radon concentrations exceeding the reference levels and minimising radon concentration in new buildings in areas with high radon potential. The key elements for a successful Plan will rely on collaboration with government sectors and other health promotion programmes, cooperative efforts involving technical and communication experts, and partnering with building professionals and other stakeholders involved in the implementation of radon prevention and mitigation.

Session 7.1 Other NORM Industries

Trend of strengthening clearance regulation in Japan and concerns about its worldwide effects on regulations for natural and artificial radionuclides

T. Hattoria

Nuclear Technological Research Laboratory, Central Research Institute of Electric Power Industry, 2-11-1 Iwadokita, Komae-shi, Tokyo, Japan; thattori@criepi.denken.or.jp

The Nuclear Regulatory Authority (NRA) of Japan drafted a revised guide on measurement and evaluation for clearance on June 5, 2019, including a decision on how to treat the uncertainty in the measurement and nuclide vector (ratio of difficult-to-measure nuclides such as beta and alpha emitters, e.g., Sr-90 and Pu-239, to easy-to-measure nuclides such as gamma emitters, e.g., Co-60 and Cs-137). This draft guide was open to public comments until July 5, 2019. Many radiological protection (RP) experts submitted comments objecting to the NRA’s overly strict decision on the uncertainty in the measurement and nuclide vector in compliance with the clearance level. To resolve such an issue on the uncertainty in clearance, a probabilistic approach was previously established in the Atomic Energy Society of Japan (AESJ) Standard (2005) and incorporated in IAEA Safety Report No. 67 (2012). The NRA’s new decision on the uncertainty in clearance is up to about 10 times stricter than the probabilistic approach. Since last year, this issue has also been discussed at an international level in the frame of the ongoing revision of the IAEA Safety Guide RS-G-1.7. This discussion on the uncertainty in clearance has raised serious concerns about the effects on other RP regulations worldwide. This is because if we need strict treatment for uncertainty even in the case of compliance with a trivial dose criterion for clearance, the same or stricter treatment for conformity might be applied to other RP criteria for doses larger than 10 mSv/year, e.g., dose limits for workers and the public, national regulatory levels for radon concentration, surface contamination criteria for daily radiation control using survey meters, derived discharge limits for liquid and gaseous natural and artificial materials, and on- and off-site measurements in Fukushima. Originally, RP criteria were not the borderline between safety and danger. The effective dose criterion for clearance (or exemption) is a typical borderless case, because it is defined as a flexible value of the order of 10 mSv/year. Also, note that many conservative assumptions are included in the derivations of such RP criteria. The regulators and RP experts should be aware of the essential meaning of the RP criteria by considering the background scientific basis when they were established. Moreover, consideration should be given to the extensive national resources that must be supplied by both private and governmental organizations having nuclear reactors and facilities handling radioactive isotopes or accelerators, including hospitals and universities, when strict regulations with excessive conservatism are imposed.

NORM and NORM Waste Management in China

Senlin Liu

China Institute of Atomic Energy, P.O. Box 275, Beijing, 102413, China ; slliu@ciae.ac.cn

This presentation gives an overview on NORM exposure level and NORM waste management in China. The mineral resources in China are divided into four categories: metallic, non-metallic, energy, and water and gas. According to China's Land and Resources Bulletin in 2007, 171 types of minerals have been discovered throughout the country, including 159 with commercial values. The total number of employees in all NORM industries is about 24.4 million with an annual collective effective dose of 26,827 man⋅Sv, so the annually averaged effective dose is about 1.10 mSv per individual. Among the employees, 43% work in agricultural greenhouses, 30% in transportation and 19% in coal mining. The agriculture greenhouse group contribute the highest collective effective dose, accounting for 56% of the total collective effective dose, followed by coal mining group and the non-ferrous metals mining group, accounting for 30% and 12%, respectively. The highest annually averaged effective dose is about 5.43 mSv which is from non-ferrous metal mining, with a maximum of 10.3 mSv. According to the first national survey of pollution sources, the total solid NORM waste is 171.4 million tons, among which the production of iron, coal and copper contributed 74.64 million tons, 49.37 million tons and 10.87 million tons, respectively. Solid waste from the niobium and tantalum industries has the highest average levels of U, 232Th, 226Ra, which are 7.4 Bq/g, 4.2 Bq/g and 7.2 Bq/g, respectively. It was followed by waste from the rare earth industry, with 2 Bq/g, 4.9 Bq/g and 1.2 Bq/g; the zircon industry, with 1 Bq/g, 0.3 Bq/g, 0.9 Bq/g; and the tin industry, with 0.9 Bq/g, 0.8 Bq/g, 1.4 Bq/g. From the high radioactive values of U, 232Th, 226Ra, etc., rare earths were the highest, reaching 83 Bq/g, 85 Bq/g, 54 Bq/g, respectively. The second is niobium tantalum, which is 36 Bq/g, 22 Bq/g and 35 Bq/g. Then there are zircon and coal mines, which are, respectively, 10 Bq/g, 2 Bq/g, 7 Bq/g and 7 Bq/g, 1 Bq/g and 92 Bq/g. In addition, the level of radionuclides in some iron ores is also high, reaching 6 Bq/g, 2.2 Bq/g and 10 Bq/g, respectively. There are a series of regulations and criteria for the management of NORM residues and NORM wastes in China. At present, it is more focused on the application and safe disposal of NORM residues.In recent years, China has started to pay attention to the radiation safety problems caused by oil and natural gas exploitation.

Session 8 Healthcare Practitioners

Use of Artificial Intelligence in CT Dose Optimization

C.H. McCollougha, S. Leng

CT Clinical Innovation Center, Department of Radiology, Mayo Clinic, 200 First Street SW, Rochester, MN, USA; mccollough.cynthia@mayo.edu; leng.shuai@mayo.edu

Since the introduction of x-ray computed tomography (CT) in 1971, ongoing technical advances have made possible clinical applications only imagined by Hounsfield, who received a Nobel prize in Medicine for his invention. In parallel, a wide range of dose optimization approaches have been implemented on commercial CT systems. Today, the field of artificial intelligence (AI) is transforming almost every aspect of modern society, including medical imaging. In CT, AI holds the promise of enabling further reductions in patient dose through automation and optimization of data acquisition processes, including patient positioning and setting acquisition parameters. Subsequent to data collection, optimization of image reconstruction parameters, advanced reconstruction methods, and image denoising improve several aspects of image quality, but primarily reduce image noise, enabling the use of lower doses for data acquisition. Finally, AI processes such as automated organ segmentation, and detection and characterization of disease states and injury, have been translated out of the research environment and into the clinic to bring automation, increased sensitivity, and new clinical applications to patient care, ultimately increasing the benefit to the patient from medically justified CT examinations. In summary, since CT’s introduction, a large number of technical advances have enabled increased clinical benefit and decreased patient risk, not only by reducing radiation dose, but also by reducing the likelihood of errors in the performance and interpretation of medically justified CT examinations.

Effective dose in medicine

C J Martin

Department of Clinical Physics and Bioengineering, University of Glasgow, Gartnavel Royal Hospital, Glasgow, G12 0XH

Abstract: Effective dose is a radiological protection quantity devised by ICRP to enable judgments about the acceptability of risks in work with radiation. It is calculated from the weighted average of organ equivalent doses, where the weighting factors provide a simplified representation of contributions to the stochastic detriment from cancer and hereditary effects derived from epidemiological studies. Cancer risk is based on the linear extrapolation of risk per unit dose down to low doses that is considered the best approach based on current knowledge. In medicine imaging examinations using ionising radiation are performed on different parts of the body for diagnosis, management, and treatment of a wide range of diseases. A quantity is needed to give information about risk, because air kerma incident on a patient from an x-ray examination or the radioactivity injected for nuclear medicine cannot provide this. Effective dose has been used widely to allow doses for different types of procedure to be compared. The risks on which effective dose is based have been derived from populations of all ages, so while medical exposures may relate to individuals, effective dose applies to a sex-averaged reference person exposed in the same way. Nevertheless it has proved a valuable quantity for use in medical applications where it gives a general understanding of the dose levels involved and provides a generic indicator for classifying medical procedures into broad risk categories. Estimates of effective dose are used in comparisons of diagnostic and interventional imaging modalities that give different spatial distributions of radiation within body tissues (e.g. CT and nuclear medicine). Effective dose can be used prospectively to inform decisions on justification of patient diagnostic and interventional procedures and planning requirements in research studies, and retrospectively in assessments of small unintended exposures of patients. It is valuable in providing a single dose quantity that can be used for communicating relative risks to clinicians and patients. However, its application has often extended beyond the simple evaluations in which it plays a useful role. In the publication being prepared ICRP sets out purposes for which effective dose is recommended in medicine and applications for which measurable quantities are preferred.

Session 9 Role of Equipment Manufacturers in Radiological Protection

What’s the point of innovation in patient dose monitoring?

J. Hislop-Jambrich PhD

Global Research and Development, Australia and New Zealand, Canon Medical, Level 2, Building C, 12-24 Talavera Road, North Ryde NSW 2113; jhislop@medical.canon

The Medical Futurist says that Radiology is one of the fastest growing and developing areas of medicine, therefore this might be the speciality in which we can expect to see the biggest steps in development. So why do they think that, and does it apply to dose monitoring? The move from retrospective dose evaluation to a proactive dose management approach represents a serious area of research. Indeed, artificial intelligence (AI) and machine learning (ML) are consistently being integrated into best-in-class dose management software solutions. The development of clinical analytics and dashboards are already supporting operators in their decision making; and these optimizations if taken beyond a single machine, beyond a single department or beyond a single health network, have the potential to drive real and lasting change. The question is for whom exactly are these innovations being developed? How can the patient know that their scan has been performed to the absolute best that the technology can deliver? Do they know or even care how much their lifetime risk for developing cancer has changed post examination? Do they want a personalized size-specific dose estimate, or perhaps an individual organ dose assessment to share on Instagram? Let’s get real about the clinical utility and regulatory application of dose monitoring and shine a light on the shared responsibility in applying the technology and the associated innovations.

Global Spread of Particle Therapy and Consideration of Radiation Safety

Kazuo Tomidaa

Particle Therapy System Division, Smart Digital Solution Business Development Division, Hitachi, Ltd., 2-1 Shintoyofuta, Kashiwa, Chiba, 277-0804, Japan; kazuo.tomida.zf@hitachi.com

Due to a glowing demand of radiation therapy for cancer or non-cancer treatment, particle therapy facility has been spreading all over the world and more than 220,000 patients have been treated with the particle therapy. This presentation will address development history and cutting edge technology of the particle therapy as well as radiation protection and safety measures including radiation shielding, access control and system safety.

Technical developments in PET.CT imaging and their impact on radiation dose reduction

T. Lagana

Siemens Healthineers, Perth, Australia

Since the introduction of integrated PET.CT at the turn of the century there have been many technical advancements that have resulted in significant image quality improvements on both the PET and CT components of the scanners. Many of these developments have resulted in a reduction in radiation dose for both patients and staff in Molecular Imaging departments. This presentation will explore some of these technological advancements and the impact they have had on radiation dose including, the introduction of Time-of-Flight imaging, Point Spread Function, the impact of extended fields of view, the recent introduction of SiPM based detector systems and the trend toward ultra-long FOV scanners.

Session 10 Patient Focus

Ethical aspects in the use of radiation in medicine: Update from ICRP task group 109

François Bochud, Marie Claire Cantone, Kimberly Applegate, John Damilakis, Maria del Rosario Perez, Frederic Fahey, Chieko Kurihara-Saio, Bernard Le Guen, Jim Malone, Margaret Murphy, Friedo Zölzer

IRA Lausanne University Hospital, Rue du Grand-Pré 1, CH-1007 Lausanne, Switzerland; francois.bochud@chuv.ch, University of Milan, Via Pascal 36, 20122 Milan, Italy; marie.cantone@unimi.it, University of Kentucky, 101 Main Building, Lexington, Kentucky, USA; keapple5123@gmail.com, University of Crete, Faculty of Medicine, Voutes University Campus, P.O. Box 2208,7100 Iraklion, Crete, Greece; john.damilakis@med.uoc.gr, World Health Organization, 20 Avenue Appia, Geneva, 1211 Switzerland; perezm@who.int, Boston Children's Hospital, Department of Radiology, Harvard Medical School, Boston Massachusetts, USA; frederic.fahey@childrens.harvard.edu, National Institute for Quantum and Radiological Sciences and Technology,, 4-9-1 Anagawa, Inage-ku, Chiba-shi, Chiba, Japan; chieko.kurihara@nifty.ne.jp, IRPA, c/o EDF—1 place Pleyel, 93282 SAINT DENIS CEDEX, France; bernard.le-guen@edf.fr, School of Medicine, Trinity College, Dublin, D02 NW44. Ireland; jifmal@gmail.com, WHO Global Network of Patients for Patient Safety, Dublin, D01, Ireland; margaretmurphyireland@gmail.com, Institute of Radiology, Toxicology and Civil Protection at the Faculty of Health and Social Sciences of the University of South Bohemia, J. Boreckého 1167/27, 370 11 České Budějovice, Czech Republic; zoelzer@zsf.jcu.cz

Scientific evidence is the basis for recommendations and guidance on radiological protection. When it is lacking, professional ethics is critically important to guide professional behavior. The International Commission on Radiological Protection (ICRP) established a task group (TG 109) to advise medical professionals, patients, families, carers, the public and authorities about the ethical aspects of radiological protection of patients in the diagnostic and therapeutic use of radiation in medicine. Occupational exposures and research-related exposures are not within the scope of this task group. The TG will produce a report that will be available for consultation to the different interested parties to receive comments before publication. Presently, the report is at the stage of a working document that also benefitted from an international workshop organized on the topic by the World Health Organization (WHO) in Geneva, in September 2019. It presents the history of ethics in medicine in ICRP, explains why this subject is important and the benefits it can bring to the standard biomedical ethics. Then, because risk is an essential part in decision-making and communication, a summary is included on what is known about the dose-effect relationship, with an emphasis on the associated uncertainties. Once this theoretical framework has been presented, the report becomes resolutely more practical. First, it proposes an evaluation method to analyse specific situations from an ethical point of view. This method allows the stakeholders to review the augmented core ethical values identified by the ICRP and provides hints on how they could be balanced. Then a wide range of situations (e.g. pregnancy, elderly, paediatric, end of life) is considered in two steps: first within a realistic ethically challenging scenario on which the evaluation method is applied; and the second within a more general context. Scenarios are presented and discussed, with attention to specific patient circumstances, and on how and which reflections on ethical values can be of help in the decision-making process. Finally, two important related aspects are considered: how should we communicate with patients and family, and how ethics should be incorporated into the education and training of medical professionals.

Patients' perspectives on radiation in healthcare

Mrs Lee Hunt

Retired, North Sydney, Australia

It was in September 2005 when I discovered the lump that was to turn my world upside-down. My GP organised a fine needle biopsy to be undertaken by a radiologist, but when the results came back within five days-it wasn't good news.

Prior to surgery, undertook nuclear medicine tests to identify the sentinel lymph nodes. These are the closest draining lymph nodes near the breast tumour which would be removed along with the tumour. Pathology following surgery indicated that the tumour hadn't spread to the surrounding tissue. Nor were there any cancer cells in the sentinel nodes. I was diagnosed with HER2 positive breast cancer, a grade 3 tumour. HER2 positive breast cancers make too much of the HER2 protein . The HER2 protein sits on the surface of cancer cells and receives signals that tell the cancer to grow and spread. HER2 positive breast cancers tend to be more aggressive and harder to treat.

The clinical team of the surgeon, oncologist and radiation oncologist studied the test results and together worked out my care path. They would work as a team to give me the best outcome possible. I had utmost faith in their expertise, knowledge and experience.

My treatment consisted of AC chemotherapy, a combination of Adriamycin and Cyclophosphamide, a 30 cycle course of radiation therapy, and a new targeted drug, Herceptin. At the MDT clinic I was warned my lung could be burnt by the radiation, my hair would fall out and I'd need a cocktail of additional drugs to combat the nausea of chemotherapy. Unfortunately I was not in a strong emotional state to comprehend how my therapy would impact on my life, but on reflection, how can one be? I knew a little about chemotherapy, but had no knowledge regarding radiation therapy. I wasn't given any written information about the three treatments nor specifics regarding therapy side-effects. I was a passive recipient of information given by specialists who were trying to put a positive light on the treatment regime which would lead to a successful outcome.

I really suffered during chemotherapy. My hair started to fall out in the second week, my weight dropped to 40 kgs, I had massive ulcers in my mouth and I thought I would lose all my teeth. Having survived the chemotherapy, I felt the following treatments would be a breeze in comparison.

My six weeks of radiation therapy were not too physically or mentally taxing. The only noticeable side effects during treatment were burning of the skin and tiredness. I was not so fortunate with the Herceptin therapy. I proceeded well on the drug for about six cycles. Every three cycles I had to have nuclear medicine to test how the drug was affecting my heart. In the MUGA scan, a tiny amount of radioactive material was injected into a vein in my arm. This material temporarily hooked onto my red blood cells. A camera, that can detect the radioactive material, took pictures of the blood flow though my heart as it beat. The test following my sixth cycle revealed that my heart was being affected. I was given a three cycle break to try and recover good heart function. I was physically exhausted as the raised adrenalin level I was experiencing, which was trying to keep my heart pumping, prevented me from sleeping.

A few years later I started to experience further symptoms from my cancer treatments. I was at a shopping centre when an excruciating pain travelled from the base of my oesophagus upwards to the back of the throat. The staff at the centre immediately thought I was having a heart attack, as I fell to my knees with the severity of the pain. After five or so minutes the pain passed. The same symptoms happened again several times.

An endoscope examination by the gastroenterologist revealed that my oesophagus was rigid in sections. He believed that the stiffness was caused by the radiation therapy. On his advice I have had to adjust my diet so that I don't eat solid dry foods that can cause my oesophagus to spasm.

A new symptom emerged a few years ago. I would be involved in an activity and then I would suddenly feint. It is believed that my heart muscle has been affected by the AC chemotherapy. Adriamycin drugs are most commonly linked to changes in the heart muscle. I undertook vascular surgery to improve the blood flow to my heart. As further side effects develop I have learnt to treat them or modify my life. I have undergone extensive dental work as the chemotherapy affected my tooth enamel. I have lost strength in my hands. This means I can't drive for long distances, so I walk or use public transport.

Each cancer patient has a different story. Survival rates for most cancers have improved over the past few decades. Highly tailored, more effective treatments have been developed to target different cancers, providing better cancer control and fewer side effects. However, improved survival rates has resulted in many patients having to live with the legacy of treatment side-effects and the impact on their quality of life.

Side effects of RT

Like all other cancer treatments radiation therapy often causes side effects. These are different for each person and depend on the type of cancer, its location, the radiation therapy dose and the patient's general health. Most people will have some mild side effects during and just after treatment.

As more people are surviving cancer and living longer, knowledge about long-term effects of treatment is expanding.

Secondary cancers from RT

Radiation therapy is an integral part of cancer treatment with more than 50% of all cancer patients needing radiation therapy at some point of time. With advances in treatment, the number of long-term cancer survivors has significantly increased. Studies have clearly shown that anti-cancer treatment has the potential to induce new primary malignancies.

One of the important late side effects of radiation therapy are radiation-induced second malignancies RISM. Many factors contribute to the development RISM, such as age at radiation, dose and volume of irradiated area, type of irradiated organ and tissue, radiation technique and individual and family history of cancer.

There is a growing concern in oncology because of the increased number of cancer survivors and efforts are being made to prevent or decrease the incidence of RISM.

Radiation therapy contributes to about 5% of the total treatment related second malignancies. However the incidence of only radiation on second malignancies is difficult to estimate because there are multiple factors that predispose the patient.

As children and young adults are likely to survive for longer duration after anti-cancer therapy, they are at the greater risk of developing RISM. For a given dose, children are around 10 fold more sensitive to develop RISM as compared to adults. Several studies have indicated that for a given dose of radiation, women are more prone to develop a second malignancy as compared to men.

Use of older radiation techniques have been shown to increase the risk of RISM. The use of intensity- modulated radiation therapy (IMRT) where a higher amount of normal tissue is exposed to a low dose of radiation that may lead to higher integral dose and thus a higher risk of RISM. However, long-term follow up data is required to draw a solid conclusion.

As of now, there is little information available about those factors which can be modified to reduce the risk of a second malignancy. One of the main reasons that patients who receive RT are at a high risk of developing a second cancer is their life style, environmental factors and genetic predisposition. There is a strong need for integrated research involving clinical studies, radiobiology and physics to estimate and reduce the risk of treatment related second cancers.

Cardiotoxicity

Cardiotoxicity, problems in the heart and vascular system, can develop within days or months after radiation but often develops years later. Cardiotoxicity can reduce the patient's quality of life and increase the risk of death from cardiac-related causes. Cardiotoxicity is a risk when a large volume of heart muscle is exposed to high dose of radiation. Radiation can injure the pericardium, the tissue covering the heart, myocardium, the heart muscle itself, the heart valves, coronary arteries and the heart's electrical system.

It is becoming clear that the longer a patient lives after cancer treatment, the more likely that damage to the heart will develop. Patients who develop radiation-related cardiotoxicity should be under the care of a cardiologist who understands the relationship between cancer treatment and heart problems. Although cardiotoxicity can be life-threatening, many of these problems can be managed effectively with medication and minimally invasive treatments.

Damage to Surrounding Tissue

Radiation-induced fibrosis is a long-term side effect of external beam radiation. Radiation therapy can cause an increased production of fibrin and makes tissues less stretchy. Fibrin is a protein found in the body that accumulates and causes damage in radiated tissue over time. How this affects the patient depends on which part of the body was treated. Fibrosis may cause the bladder to hold less urine, the breast to feel firmer, the arm or leg to swell, breathlessness due to the lungs being less stretchy and narrowing of the oesophagus, making it difficult to swallow.

Radiation-induced fibrosis evolves rapidly and aggressively in some patients, whereas it develops gradually, even years later, in others due to complex, poorly understood mechanisms. It is a potentially painful, life- long condition, as the tissue changes are permanent.

For patients with established radiation-induced fibrosis, treatment is primarily symptomatic. There is a real need for ongoing research to find therapies that can prevent formation of fibrosis or to treat the disease. One area of research is examining how a special type of massage using deep friction can affect radiation- induced fibrosis beneficially. When delivered in intensive sessions, using deep friction techniques, massage has the potential to break down fibrotic tissues, releasing inflammation and free radicals that are caused by radiation therapy. In the course of the massage, painful and debilitating spasms resulting from fibrosis can be relieved. Prevention has focused on improvements in RT technique, which have resulted in higher doses to the tumour target and decreased doses to normal tissue, thus potentially preventing the development of radiation -induced fibrosis.

Nuclear medicine both scans and nuclear medicine therapy

The dose of x-rays or radioactive materials used in nuclear medicine imaging can vary widely. In general, the dose of radiopharmaceutical given is small and the patient is exposed to low levels of radiation during the test. The potential health risks from radiation exposure are low in comparison to the benefits. In my case, having a sentinel node scan meant that only four nodes were removed during my surgery. The procedure left the other non-involved, functional lymph nodes intact. The procedure allowed critical treatment insights with the least possible surgery and trauma. It also meant I had a much lower risk of developing lymphedema.

Patients do receive higher amounts of radiopharmaceuticals for nuclear medicine therapy. Radioactive liquid treatments are used for some types of cancer, such as radioactive iodine therapy which can be used for thyroid cancer. It is targeted radiation therapy because the treatment goes straight to the cancer and has very little effect on healthy cells in the body. Possible long term effects are lowering of fertility, inflammation of the salivary glands, dry or watery eyes or lung problems.

Compare Rt in 2005 to RT today see if I can get RT plans from 2005 to plans 2019

Patient Information sheets at first appointment-standardise written information

The main goal of cancer treatment is to extend life, but the quality of that extended life is also important for the patient. The researcher, doctor and patient team needs to embrace physical, mental and emotional health and incorporate quality of life in their treatment options. The World Health Organisation has noted that the main goals of cancer treatment are not only to cure or prolong patient lives, but also 'to ensure the best possible quality of life for cancer survivors.'

Some patients don't care much how a treatment affects quality of life. They want to fight to get to a particular milestone, even if quality of extra life is poor. For others, quality of life is as important as length of life, or maybe even more so.

The radiation risks and side effects from both radiation therapy and nuclear medicine therapy need to be effectively communicated to the patient. Frequently in the culture of "doctor knows best", the cancer patient trusts their doctor to do what is appropriate and doesn't discuss the attendant risks associated with the tests and therapy.

However, the patient needs to be informed of the risks and known side effects prior to the procedure or therapy and should be given the opportunity to discuss the matter in more detail with the treating specialist. The patient needs to be able to analyse the benefits against the risks. If the patient is able to review the side effects, they can decide if they can endure the effect or not. The patient should also be made aware of how common the side -effects are and options for managing the side effects.

Providing cancer patients with information helps with decision making, prepares them for treatment and helps with managing adverse effects associated with it, reduces anxiety and depression, increases satisfaction with treatment and helps to improve their quality of life.

My view of RT, positive, negative. Then and Now and my care

Having had a recurrence of cancer last year, I approached my diagnosis and therapy with a more informed and objective manner. During the diagnostic tests I asked the radiologist to give me the exact facts and not try to sugar coat the results. The information provided reduced my uncertainty, and therefore relieved my anxiety and stress . I was involved and treated as an active participant in decision making by every member of the treatment team. It is crucial that the specialist identifies and addresses the information needs of cancer patients in order to help them make decisions and cope.

To support understanding by patients, the creation of patient-centred resources regarding radiation treatment and side effects are needed to give the patient a detailed understanding of what the treatment involves. Written information allows the patient to reflect on what will be involved during the therapy, enables an accurate understanding for discussion with family and friends and becomes an excellent reference for managing both short and late onset therapy side effects.

Current research: improved control of cancer and reduced toxicity,

Major advances in radiation therapy have made it more precise, reducing side effects and improving cancer control. It is more accurate than it has ever been. Current techniques such as conformal radiation therapy and intensity modulated radiation therapy (IMRT) accurately shape the beams to fit the cancer. This means less healthy tissue receives radiation, and so there are fewer side effects.

Research continues to look into ways to make radiation therapy more precise.

metastatic cancer clinical trial

A clinical trial has found that high-dose radiation is effective for men whose prostate cancer has spread. (Oncology News 30 Sept 2019)

In some situations, metastatic cancer can be cured, but most commonly treatment does not cure the cancer. Treatment can slow its growth and reduce symptoms and it is possible to live for many months or years with certain types of cancer, even after the development of metastatic disease.

A randomised clinical trial of targeted, high-dose radiation therapy for men with oligometastatic prostate cancer has shown the treatment to be an effective and safe option for patients who wish to delay hormone- suppression therapy. The phase II trial found that radiation therapy can generate an immune system response not previously believed possible in this type of cancer.

Previous research has shown high-dose radiation to be safe for men with localised or non-metastatic prostate cancer, but patients whose cancer has been treated but then returned to a limited number of other parts of the body, generally have been considered incurable.

A few studies and limited prospective data have recently suggested that high-dose, targeted radiation may be effective for men whose prostate cancer had spread. The ORIOLE randomised data confirm those observations. The men treated with stereotactic ablative radiation therapy (SABR) also known as stereotactic body radiation therapy (SBRT), to the metastatic sites outside of the prostate, were significantly less likely to experience increases in their PSA levels and lived significantly longer without any detectable disease progression. Six months later, just 19% of the patients treated with SABR saw their disease progress, compared to 61% of those in the observation arm.

The ORIOLE trial has shed light on what happens to the immune system when the disease is treated with high-dose radiation therapy. The research team looked at blood cells sampled before radiation therapy and 90 days after treatment. They found 'significant, measureable changes' in the T cells of patients on the SABR arm, but no change in the T cells of those in the observation arm. This suggests that radiation therapy may spark the immune system to more aggressively fight the cancer.

Radiation Protection Challenges in Applications of Ionising Radiation on Animals in Veterinary Practice

N.E. Martinez, L. Van Bladel

Department of Environmental Engineering and Earth Sciences, Clemson University, 342 Computer Ct, Anderson, SC, 29625, USA; nmarti3@clemson.edu, Federal Agency for Nuclear Control, Rue Ravenstein 36, 1000 Brussels, Belgium; lodewijk.vanbladel@fanc.fgov.be

As we work towards a holistic approach to radiation protection, we begin to consider and integrate protection beyond humans to include, among other things, non-human biota. Non-human biota not only includes the flora and fauna of the environment, but also livestock, companion animals, working animals, and the like. Although under consideration, there is currently little guidance in terms of protection strategies for types of non-human biota beyond wildlife. For example, in recent years veterinary procedures that make use of ionizing radiation have increased in numbers and have diversified considerably. Digitalization of planar X- ray procedures, CT-scanning, interventional radiology applications, radiotherapy and nuclear medicine procedures are all accompanied by greater potential radiation risks than the plain film-screen X-rays we have known in previous decades. These techniques are primarily used in veterinary medicine, although diagnostic techniques are also quite commonly used for economic purposes rather than for the health care of the examined animal, such as in the case of pre-sales exams on racehorses or show-jumpers. Changes in these practices have made radiation protection in veterinary applications of ionizing radiation more challenging, both for humans and the animal patients. In fact, the common belief that doses to professionals and members of the public from these applications will be very low to negligible, and doses to the animals will not be acutely harmful nor even affect their lifetime probability of developing cancer, needs to be revisited in the light of higher dose diagnostic and interventional techniques and certainly in case of therapeutic applications. With that in mind, we are left with questions such as: What is reasonable protection for an animal patient? What are best practices for protecting those (humans) involved in, or directly affected by, these applications? What factors should we consider and how do we determine, and then balance, the risk and benefit in such situations? This presentation provides a brief overview of the initiatives of the ICRP concerning radiation protection aspects of veterinary practice and poses a variety of questions and perspectives for consideration and further discussion.

Session 11 Radiological Protection in Space

20 years of radiation protection experience with the International Space Station

M.R. Shavers

KBR Government Services, NASA Johnson Space Center, 2101 NASA Parkway, Houston, TX 77058, USA; mark.r.shavers@nasa.gov

The International Space Station (ISS) was first occupied by crew in October, 2000, and now has been continuously inhabited for over 19 years. NASA and its partner agencies from Russia (FSA), Europe (ESA), Japan (JAXA), and Canada (CSA) are actively engaged to maintain exposures as low as reasonably achievable (ALARA) and below limits that ensure safety from early or late deleterious effects. The altitude of the low Earth orbit (LEO) that ISS occupies at 51.6 degrees inclination has varied between ~335 km to over 420 km. The ionizing radiation environment in this orbit is complex and dynamic; many factors combine to constantly change its composition, intensity, and directionality. The ISS provides a relatively high mass of shielding compared with smaller structures, such as a light lunar lander, pressurized surface rover, or a spacesuit used for extravehicular activity (EVA, or “spacewalks”). Not surprisingly, shielding complicates the LEO radiation environment further, removing and producing additional energetic electrons, protons, neutrons, heavy ions, pions, and electromagnetic fields. The radiation environment over short time intervals is considered to be low dose and low dose-rate. Still, multiple missions or a single ISS mission for close to a year duration may expose an astronaut to over 100 mGy. Since cancer induction was the potential long-term health effect of greatest concern, NASA developed an analytical model to evaluate the excess risk of cancer incidence and mortality, the NASA Space Cancer Risk Model 2012 (NSCR-2012). For each NASA crew member, the current implementation of the model incorporates individual sex and age at mid-mission to evaluate organ absorbed doses, a customized version of effective dose, and a probabilistic assessment of the Risk of Exposure-Induced Cancer incidence (REIC) and Death (REID). Compliance with the NASA Standard has been demonstrated by comparing each U.S. astronaut’s full NASA occupational exposure history with the career exposure limit, which is 3% excess cancer mortality evaluated at the upper limit of the 95% confidence interval. An individual astronaut’s radiation exposure history report will be reviewed and contrasted with conventional ICRP dosimetry metrics. Non-ionizing radiation (NIR) sources of exposure are also present from onboard systems, an increasing number of scientific payloads, and from sunlight through high optical quality windows. Each NIR source is monitored in the context of the operational environment and engineering controls are in place to limit exposure to these hazards.

Radiation environment in space and recent progresses on space weather research for cosmic-ray dosimetry

T. Sato

Nuclear Science and Engineering Center, Japan Atomic Energy Agency, Shirakata 2-4, Tokai, Ibaraki 319-1195, Japan; sato.tatsuhiko@jaea.go.jp

The radiation environment in space is a complex mixture of particles of solar and galactic origin with a broad range of energies. For astronaut dose estimation, three sources must be considered, namely, galactic cosmic rays (GCR), trapped particles (TP), and solar energetic particles (SEP). GCR enters the heliosphere continuously from all direction, and they are modulated by the interplanetary magnetic field produced by the charged particles emitted continuously by the Sun, the so-called ‘solar wind’. Thus, their fluxes gradually change with the solar activity, which has a period of approximately 11 years. TP is trapped in the Earth’s magnetic fields as a results of interaction of GCR and SEP with the Earth’s magnetic field and the atmosphere. Thus, they contribute to the astronaut doses only for the Earth orbit missions. SEP is emitted from the Sun’s surface due to the coronal mass ejection (CME) over the course of hours or days. By contrast to GCR and TP, the astronaut dose due to SEP exposure during a space mission is hardly expectable because the occurrence of a large CME is unpredictable by the current space weather research. Thus, the worst-case scenarios are generally considered in mission design. More details about the radiation environment in space will be discussed at the symposium, together with the recent progresses on the space weather research for nowcasting and forecasting the astronaut doses due to SEP exposure.

Operational Radiation Protection for Human Space Flight, the Flight Surgeons Perspective

U. Straube

60 years and counting. Yuri Gagarin was “the first human in space” in 1961. Already eight years later Neil Armstrong left his footprints on the Moon. The first human on the surface of a celestial body other than Earth. By now, long duration missions up to one year became a reality for humans in space. Overall nearly nineteen years of continues human presence on the International Space Station, ISS provide unique insight into human life in space. Humans are reaching out for more, targeting missions to bring them outside the protective hull of Low Earth Orbit into Deep Space! The challenges to human health and well-being remain to be significant. More so, they do increase with distance and time. The lack of gravity, the ubiquitous Ionizing radiation, remoteness and confinement are just some representatives to be named, that are dominating the hostile environment of space. More hurdles have to be overcome prior to the human endeavour of reaching out into deep space. Radiation in space is one of such primary and inevitable factors that are key to crew- health, -safety and so overall mission success. This presentation will give you an introduction into operational space medicine and radiation protection for humans in space as executed on ISS, in Low Earth Orbit, and in preparation for the scenarios “beyond”.

Session 12 - Current Practice

Current Canadian Space Agency practice and activities in the area of radiation health protection

L. M. Tomi

Canadian Space Agency, 6767 route de l’.Aéroport, Saint-Hubert, QC J3Y8Y9, Canada; leena.tomi@canada.ca

The Canadian Space Agency (CSA) is a partner in the International Space Station (ISS) Program, along with the United States (managing partner), Russia, Japan, eleven member states of the European Space Agency and Brazil. Ensuring the overall health and safety of the ISS crews is the joint responsibility of the medical support offices of each international partner through participation in the ISS multilateral medical management groups, including the Multilateral Medical Operations Panel (MMOP). Radiation health and safety of the ISS astronauts has been overseen by the ISS MMOP Radiation Health Working Group since 1999. The medical standards developed are stipulated in the ISS Program medical operations documents which outline the joint requirements pertaining to medical selection and certification, countermeasures definition and implementation, medical and environmental monitoring, response capability for in-flight medical events, and operational hardware and ground support. In February 2019, Canada joined the NASA-led Lunar Gateway project. It is expected that the Gateway program will use the multilateral medical oversight framework developed for the ISS. This paper reviews CSA practices developed for astronaut radiation health protection in accordance with national and ISS Program standards. It also reviews radiation monitoring activities and research supported by CSA Operational Space Medicine in this area.

The ethical considerations of radiological protection in space

N.L Coleman

Royal Australian Air Force, Russell, ACT, Australia; e-mail: n.coleman@adfa.edu.au UNSW Canberra Space; Case Western Reserve University; dRAAF Air Power Development Centre

Since humans first stepped on the moon 50 years ago, we have been looking for ways to make space travel safer, so that we can explore beyond our own region of the solar system. The current limiting factor for extended space travel is not merely faster and more efficient space craft, but also how we protect humans through these journeys and potentially protect them whilst on distant planets. This paper will examine some of the ethical considerations relating to radiological protection in space, and ask the question of what we owe to future generations in getting these questions right.

Practicalities of dose management for Japanese ISS astronauts

Tatsuto Komiyama

Astronaut Medical Operations Group, Astronaut and Operation Control Unit, Human Spaceflight Technology Directorate, Japan Aerospace Exploration Agency (JAXA), 2-1-1 Sengen, Tsukuba-city, Ibaraki, 305-8505 Japan; tatsuto.komiyama@jaxa.jp

Japanese astronaut started staying in International Space Station (ISS) for about six months per one stay in 2009. Since that time, seven Japanese astronauts have stayed in ISS eight times. Because there is no law for protection against space radiation exposure of astronauts in Japan, JAXA made own rules and have applied them to exposure management for Japanese ISS astronauts successfully, collaborating with ISS international partners.

Regarding dose management, JAXA has several dose limits to protect both stochastic effects and deterministic effects. Exposure during spaceflight, exposure during several types of training and exposure from astronaut- specific medical examination are scope of the dose limits. So, we calculate dose from all exposure applied to the dose limits annually for each astronaut. While Japanese ISS astronaut is in ISS, we monitor readings of measurement instrument in real-time to confirm the exposed dose is under the limits because space radiation environment is fluctuated by the solar activity.

Session 13 Future Challenges

Recent Progress on Chinese Space Program and Radiation Research

Guangming Zhou, Hailong Pei, Wentao Hu, Tom K. Hei

State Key Laboratory of Radiation Medicine and Protection, School of Radiation Medicine and Protection, Institute of Life Sciences in Space, Medical College of Soochow University, Suzhou 215123, China; Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions, Suzhou 215123, China; Center for Radiological Research, Columbia University Medical Center, NY 10032, USA gmzhou@suda.edu.cn

Chinese Space Station (CSS) will be launched in 2020 and will serve as a research laboratory in outer space for at least a decade. Two large scale programs with relevance to space radiobiological study will be funded and carried out in China in the future. To support the booming field of life sciences in space, several research centers have been set up that are dedicated to space radiobiological studies including our Institute of Life Sciences in Space founded in Soochow University in 2016. Multidisciplinary studies have been carried out and some progresses have been made in our laboratory, especially in radiation risk assessment and the development of countermeasures against space radiation.

We found that quiescent cells are relatively resistant to ionizing radiation including HZE particles due to the relative low expression of RAC2, a main subunit of NADPH These findings imply that risk assessment of space radiation basing on the results obtained with routine exponentially growing cells might be overestimated. These findings also highlight the potential role of cellular metabolism in modulating individual radiosensitivity.
Bystander or abscopal effects increase the concern of the health risk of space radiation among astronauts and future space travelers. We identified a feedback loop of a miR-663-TGF network, which suppresses the out of field cells to secret bystander signals, suggesting the bystander effects mediated by TGF are not enhanced unlimitedly.
We show that cytoskeleton is one of the major targets of ionizing radiation because it is a multifunctional subcellular organelle maintaining cell morphology, mediating material transportation, sensing mechanical alterations, and ubiquitous inside a We identified a long non-coding RNA, LNC CRYBG3, that regulated cytokinesis, migration, and metabolism by directly interacting with actin cytoskeleton. LNC CRYBG3 binds to the Ser14 of G-actin and inhibits the assembly of F-actin, which results in an incomplete cytoplastic division and consequent binucleated cells. Therefore, cytoskeleton-lncRNA network plays a very important role in regulating biological effects of space radiation.

Radiation protection challenges for exploration

M.R. Shavers*

KBR Government Services, NASA Johnson Space Center, 2101 NASA Parkway, Houston, TX 77058, USA; mark.r.shavers@nasa.gov

Exploration of the near-Earth space environment and the effects on humans of inhabiting that environment have been underway for nearly 60 years. With space stations inhabited by crews in low Earth orbit (LEO), the United States and other countries have observed the combined influences of potential environmental stressors such microgravity, radiation, even ambient air composition and noise levels, as well as other potential stressors such as sleep and work scheduling, nutrition and pharmaceutical drugs, and isolation from daily life on Earth. The practice of radiation protection was itself an exploratory field that arose from planning the first space exploration missions. Within ten years of reaching space, the NASA Apollo Program sent 24 men around the moon and 12 men landed on the lunar surface. With the Gateway and Artemis Programs, NASA and international partners will send the first women along with men to the lunar surface. The Gateway architecture provides a “way-station” in cis-lunar orbit that will serve first as a platform for lunar missions, and later to stage deep-space human exploration to Mars. Radiation protection (RP) practices for these exploration missions will support, initially, relatively few crews. However, international, private, and commercial enterprises will expand human presence in LEO and beyond. The “concept of operations” for supporting the first crews of exploration-class missions are being developed now by building upon and rethinking RP current practices to support long-duration travel to distant destinations.

The pre-flight, in-mission, and post-flight RP challenges for supporting planned human exploration missions will be introduced and discussed. These analytical, technical, and administrative challenges include projecting and measuring radiation environments and crew exposures, advancing strategies to manage the exposures and their potential consequences, and reviewing RP metrics and limits of exposure to ionizing radiations.

*Presenting as proxy for invited lecturer E. Semones/NASA-JSC