A radiation overdose incident: Initial data

Abstract

To estimate tolerance limits for irradiated human tissues by evaluating reactions observed in 426 patients who had received significant overdoses from an improperly calibrated cobalt unit. A data file was designed to store essential technical and dosimetric information sufficient to analyze the response, estimate complication rates, and derive dose-response functions, using hierarchical region, system, and organ coding protocols. A total of 795 discrete target tissues had been irradiated in 426 evaluable subjects studied. In 183 patients who survived beyond 1 year, there were 62 (34%) with immediate severe complications in 386 irradiated sites including brain, spinal cord, skin, oropharyngeal mucosa, colon, and rectum. This unique data set includes responses to high doses and unusual fractionation beyond the range of conventional clinical experience. It provides a resource for estimating human tissue tolerance limits, for testing clinically relevant radiobiological models and for developing new optimization algorithms.