Comparison of the Chromosome Damage and Its Dose Response after Medical Whole-body Exposure to ⁶⁰Co γ-rays and Irradiation of Blood in Vitro

Summary

Fifteen patients with advanced cancer have been exposed to a medical whole-body ⁶⁰Co γ-irradiation with doses of 10, 19 and 29 rads before local palliative radiation therapy. Chromosome analyses were carried out in lymphocytes of blood samples obtained before, immediately after, and 24 hours after the exposure of the patients as well as after in vitro irradiation of the patients' blood. A comparison of the frequencies of dicentrics + ring chromosomes revealed no significant differences neither between the two sampling times after exposure of the patients, nor between either in vivo or in vitro samples. The dose-response relations were linear. Due to the low aberration yields occurring in low dose-ranges, the applicability of chromosome damage to a biological dosimetry is a statistical problem. A meaningful dose estimation for a single person based on the 200 cells usually analysed is impossible.