Study of acute 60Co, low dose rate CF-252 and CS-137 radiation on LSA ascites lymphoma in vivo

• Published in: International journal of radiation oncology, biology, physics Vol. 11; no. 11; p. 1991
• Main Authors: Maruyama, Y, Feola, J M, Magura, C, Onomura, C I, Beach, J L
• Format: Journal Article
• Language: English
• Published: United States 01-11-1985
• Subjects: Animals; Cell Survival - radiation effects; Cobalt Radioisotopes; Female; Lymphoma - mortality; Lymphoma - radiotherapy; Male; Mathematics; Mice; Mice, Inbred C57BL; Neoplasms, Experimental - mortality; Neoplasms, Experimental - radiotherapy; Radiotherapy Dosage
• ISSN: 0360-3016
• DOI: 10.1016/0360-3016(85)90282-2

Dose response curves were determined for the LSA lymphoma for acute 60Co, low dose rate Cs-137 and Cf-252 radiations using in vivo survival time bioassay. Mean survival times increased with dose with a prominent oxygen effect noted for acute 60Co and Cs-137. OER was lowest for Cf-252 where it was approximately 1.4. The RBEn for oxic LSA cells to Cf-252 neutrons was 3.1 for acute 60Co and 4.2 for Cs-137. It was larger for hypoxic tumor and RBE was 5.3 for 60Co and 5.8 for Cs-137. Survival curves based on survival data used a multitarget dose-response model for photon radiation and exponential dose-response for Cf-252 radiation. When LSA was irradiated in advanced tumor stages in vivo, Cf-252 was much more effective than acute 60Co or LDR Cs-137 for increasing survival time. Tumor response in vivo matched the in vitro irradiated tumor data. No schedule dependence was observed for mixing of 60Co and Cf-252 radiations.