significant recent interest in radiation oncology. In addition to surgical resection and thermal ablation, the development of stereotactic body ra- diation therapy ...
E532
International Journal of Radiation Oncology Biology Physics
significant recent interest in radiation oncology. In addition to surgical resection and thermal ablation, the development of stereotactic body radiation therapy (SBRT) techniques has allowed physicians to treat many patients who are poor candidates for other treatment modalities. Our current study examines the efficacy of the surfactant Pluronic, a nonionic block copolymer of polyethylene oxide and polypropylene oxide, as a potential radiosensitizing agent for radiation treatment of human colorectal cancer. Pluronic has previously demonstrated chemosensitizing and thermosensitizing ability in a broad range of cancers. Materials/Methods: Clonogenic survival assays of human colorectal cancer HCT-116 (H6) cells were used to assess the efficacy of radiation treatments with and without Pluronic L10 (L10). Cells were plated in culture at various densities and exposed to ionizing radiation at doses of 0 to 6 Gy via a Cs-137 irradiator in the presence or absence of L10. After treatments were completed, cells were incubated for 7-10 days to allow for colony formation. Colonies were then stained with 0.1% crystal violet, and plates were digitally scanned for quantification. Colony counts were obtained via a custom particle count program using computer algorithm software. Surviving fraction (SF) was determined by normalizing to plating efficiency, and differing treatment groups were compared. Statistically significant differences (p
