title: Study of acute 60Co, low dose rate CF-252 and CS-137 radiation on LSA ascites lymphoma in vivo.
abstract: 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.
mesh_terms: D000818:Animals; D002470:Cell Survival / Q000528:radiation effects; D003037:Cobalt Radioisotopes; D005260:Female; D008223:Lymphoma / Q000401:mortality / Q000532:radiotherapy*; D008297:Male; D008433:Mathematics; D051379:Mice; D008810:Mice, Inbred C57BL; D009374:Neoplasms, Experimental / Q000401:mortality / Q000532:radiotherapy; D011879:Radiotherapy Dosage
chemical_list: D003037:Cobalt Radioisotopes