Potential biomarkers of chronic low-dose radiation exposure for nuclear medicine technologists

Purpose: Nuclear medicine is the fastest growing segment in imaging due to an increase in demand for procedures, development of advanced scanners and new radioactive tracers. Technologists are exposed to radiation throughout the workday. Key protection approaches are time, distance, and shielding; these can be difficult to achieve since patients are usually the main source of radiation and close contact is required. Technologists in general nuclear medicine receive annual effective doses of approximately 0.1 mSv. Doses in positron emission tomography (PET) imaging can be close to 6 mSv. Without appropriate radiation protection measures, finger doses from handling PET radiopharmaceuticals can exceed the annual dose limit of 500 mSv. Estimates of health risks from low dose-rate exposures are extrapolated from risk coefficients calculated from Japanese atomic bomb survivors. Effects of chronic exposure are obtained from nuclear workers and radiotherapy patients. This review aims to consolidate existing research in biomarkers of low dose radiation exposure to determine whether they may form a part in occupational health monitoring. Conclusions: The link between chronic low-dose exposure in nuclear medicine technologists and health risks using radiation-related biomarkers as a proxy remains relatively unexplored. Further work is needed to identify and characterize biomarkers in technologists.