A RADIATION OVERDOSE INCIDENT - INITIAL DATA

Purpose: 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. Methods and Materials: 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. Results: 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. Conclusion: This unique data set includes responses to high doses and unusual fractionation-beyond 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.