RADIATION-THERAPY AMONG ATOMIC-BOMB SURVIVORS, HIROSHIMA AND NAGASAKI

As a follow-up to the two previous surveys of radiation therapy among the atomic bomb survivors, a large-scale survey was performed to docum ent (1) the number of radiation therapy treatments received by the ato mic bomb survivors and (2) the types of radiation treatments conducted in Hiroshima and Nagasaki. The previous two surveys covered the radia tion treatments among the Radiation Effects Research Foundation Adult Health Study (AHS) population, which is composed of 20,000 persons. In the present survey, the population was expanded to include the Life S pan Study (LSS), including 93,611 atomic bomb survivors and 26,517 Hir oshima and Nagasaki citizens who were not in the cities at the times o f the bombings. The LSS population includes the AHS population. The su rvey was conducted from 1981 to 1984. The survey teams reviewed all th e medical records for radiation treatments of 24,266 patients at 11 la rge hospitals in Hiroshima and Nagasaki, Among them, the medical recor ds for radiation treatments of 1556 LSS members were reviewed in detai l. By analyzing the data obtained in the present and previous surveys, the number of patients receiving radiation therapy was estimated to b e 4501 (3.7%) in the LSS population and 1026 (5.1%) in the AHS populat ion between 1945-1980, During 1945-1965, 98% of radiation treatments u sed medium-voltage X rays, and 66% of the treatments were for benign d iseases. During 1966-1980, 94% of the radiation treatments were for ma lignant neoplasms. During this period, Co-60 gamma-ray exposure appara tus and high-energy electron accelerators were the prevalent mode of t reatment in Hiroshima and in Nagasaki, respectively. The mean frequenc y of radiation therapy among the LSS population was estimated to have been 158 courses/year during 1945-1965 and 110 courses/year during 196 6-1980. The present survey revealed that 377 AHS members received radi ation therapy. The number was approximately twice the total number of cases found in the previous two surveys. Thus the data on radiation th erapy in the AHS members have been updated well by this survey, and wi ll provide information for more precise dose-response analyses of radi ation effects in the AHS population, The information extracted from th e medical records of the hospitals consisted of hospital names, treatm ent periods, body sites treated, diagnoses, treatment doses, radiation sources, the field sizes of the exposures and the data for identifica tion of the patients. These data will be essential in estimating the o rgan doses from scattered radiation and in evaluating the effects of t herapeutic radiation. (C) 1998 by Radiation Research Society.