title: Comparison of the effects of neutron and/or photon irradiation on spontaneous squamous-cell carcinoma in mice.
abstract: The effect of 30MeV D+ leads to Be NIRS cyclotron neutrons on a spontaneous NR-S1 squamous-cell carcinoma was studied. The TD50 (number of tumor cells required for transplantation in half the sites) and tumor growth delay time (TGD) were determined. The RBE of 200-kVp x rays at the 10% survival level was 1.9 for aerobic cells and 2.0 for hypoxic cells; the OER at the same level was congruent to 1.7. Tumor cells irradiated with neutrons were unable to repair potentially lethal damage, in contrast to x-irradiated tumor cells. The RBE of 50-MeV D+ leads to Be neutrons was inversely related to deuteron energy for hypoxic cells. The relationship between TGD and peak skin indicated no benefit from mixed beams or 5 neutron doses.
mesh_terms: D000818:Animals; D002294:Carcinoma, Squamous Cell / Q000532:radiotherapy*; D002470:Cell Survival / Q000528:radiation effects; D004307:Dose-Response Relationship, Radiation; D051379:Mice; D009368:Neoplasm Transplantation; D009374:Neoplasms, Experimental / Q000532:radiotherapy; D009502:Neutrons; D010100:Oxygen; D011882:Radiotherapy, High-Energy; D012062:Relative Biological Effectiveness; D013047:Specific Pathogen-Free Organisms
chemical_list: D010100:Oxygen