PHYSICIANS' KNOWLEDGE ABOUT RADIATION DOSE AND POSSIBLE RISKS OF COMMON MEDICAL TESTS: A SURVEY IN IRAN.

Recent data suggest that knowledge of radiation exposures among physicians is inadequate. This study, therefore, aimed to evaluate their knowledge of the radiation doses their patients received and awareness of associated biological risks of radiation exposure. A questionnaire in multiple-choice format consisted of four sections with a total of 10 questions based on the literature review. A total of 136 questionnaires were returned from 69 general practitioners and 67 physicians in various specialties from 10 different hospitals in the capital city of Tehran, Iran. Fifty-four percent of general practitioners and twenty-five percent of specialties declared that they are not aware of biological risks of radiation exposure. Fifty-six percent of physicians did not know the correct definition of absorbed dose. Only 33% of physicians knew the dose exposure of a chest X-ray and only 31% knew the approximate doses of various procedures relative to a chest X-ray. Forty-seven percent of physicians incorrectly distinguished the stochastic effects of radiation from the deterministic effects, and thirty-eight of physicians did not know the organs of the body that are most sensitive to ionizing radiation. Only 23.5% of physicians were aware of the one in 2000 risk of induction of fatal carcinoma from computed tomography of the abdomen. Seventy-nine percent of physicians incorrectly underestimated the contribution of nuclear and radiological tests in exposure of an average person. The mean score of the specialties trended toward being more accurate than general practitioners (4.18 ± 1.28 vs. 3.89 ± 1.46, respectively, from a potential accurate total score of 9), but these differences were not statistically significant. Among specialists, orthopedics had the highest scores. The present study demonstrated the limited knowledge of radiation exposures among general practitioners and specialists and a need to improve their knowledge by means of targeted training and re-education.