Radiocytogenetic Determination of the Oxygen Enhancement Ratio of Californium 252

Abstract Californium 252 was studied as a possible replacement for radium 226 in radiation therapy. Irradiation of Chinese hamster cells with 252Cf produced an aerobic and anaerobic aberration frequency of 0.0135 and 0.0077 single-hit chromosome aberrations per cell per rad, respectively. The oxygen enhancement ratio was 1.75. This study suggests that 252Cf may be more effective than 226Ra in the treatment of malignant disease.