Radiosensitization of hypoxic cells in vivo by SR 2508 at low radiation doses: a preliminary report.

摘要: We have used the RIF-1 tumor implanted intradermally in lower dorsum of C3H mice to explore what extent radiosensitizer SR 2508 is capable sensitizing hypoxic cells at clinically relevant doses 1 and 2 Gy per fraction. injected (1000 mg/kg) 45 min prior each radiation dose fractionated regimens or 4 doses/day for up 5 days (1 Gy/fraction) given locally tumors, which were clamped occlude blood supply exposure. This necessitated design clamps totally occluded flow could be applied nonanesthetized without obvious discomfort, 20 times compromising on removal clamps. performed various experiments confirm validity these 3 requirements. The response with clamping was determined by constructing multifraction cell survival curves using vivo-in vitro assay. initial results demonstrate significant radiosensitization artificially Gy/fraction mg/kg). Using ratio D0's exponential, curves, we obtained an SER 1.6 (3 pooled) compared OER (D0 clamped/D0 air-breathing mice) 2.3 (4 pooled). These data suggest that (and presumably other electron-affinic sensitizers) can radiosensitize low doses, indicate this similar drugs may useful radiotherapy those tumors hypoxia limits curability.