摘要：Previous studies have demonstrated that X-ray irradiation affects angiogenesis in tumors. Here, we studied the effects of γ-ray irradiation on boron-10 compound accumulation in a murine tumor model. The mouse squamous cell carcinoma was irradiated with γ-ray before BSH ( 10 B-enriched borocaptate sodium) administration. Then, the boron-10 concentrations in tumor and normal muscle tissues were measured by prompt γ-ray spectrometry (PGA). A tumor blood flow assay was performed, and cell killing effects of neutron irradiation with various combinations of BSH and γ-rays were also examined. BSH concentrations of tumor tissues were 16.1 ± 0.6 μg/g, 16.7 ± 0.5 μg/g and 17.8 ± 0.5 μg/g at 72 hours after γ-ray irradiation at doses of 5, 10, and 20 Gy, compared with 13.1 ± 0.5 μg/g in unirradiated tumor tissues. The enhancing inhibition of colony formation by neutron irradiation with BSH was also found after γ-ray irradiation. In addition, increasing Hoechst 33342 perfusion was also observed. In this study, we demonstrated that γ-ray irradiation enhances BSH accumulation in tumors. The present results suggest that the enhancement of 10 B concentration that occurs after γ-ray irradiation may be due to the changes in the extracellular microenvironment, including in tumor vessels, induced by γ-ray irradiation.
