Gamma-ray irradiation enhanced boron-10 compound accumulation in murine tumors.
Previous studies have demonstrated that X-ray irradiation affects angiogenesis in tumors. Here, we studied the effects of gamma-ray irradiation on boron-10 compound accumulation in a murine tumor model. The mouse squamous cell carcinoma was irradiated with gamma-ray before BSH ((10)B-enriched borocaptate sodium) administration. Then, the boron-10 concentrations in tumor and normal muscle tissues were measured by prompt gamma-ray spectrometry (PGA). A tumor blood flow assay was performed, and cell killing effects of neutron irradiation with various combinations of BSH and gamma-rays were also examined. BSH concentrations of tumor tissues were 16.1 +/- 0.6 microg/g, 16.7 +/- 0.5 microg/g and 17.8 +/- 0.5 microg/g at 72 hours after gamma-ray irradiation at doses of 5, 10, and 20 Gy, compared with 13.1 +/- 0.5 microg/g in unirradiated tumor tissues. The enhancing inhibition of colony formation by neutron irradiation with BSH was also found after gamma-ray irradiation. In addition, increasing Hoechst 33342 perfusion was also observed. In this study, we demonstrated that gamma-ray irradiation enhances BSH accumulation in tumors. The present results suggest that the enhancement of (10)B concentration that occurs after gamma-ray irradiation may be due to the changes in the extracellular microenvironment, including in tumor vessels, induced by gamma-ray irradiation.
Research Reactor Institute, Kyoto University, Sennan-gun, Osaka, Japan.
Yong
Y
Liu
Kenji
K
Nagata
Shin-ichiro
S
Masunaga
Minoru
M
Suzuki
Genro
G
Kashino
Yuko
Y
Kinashi
Hiroki
H
Tanaka
Yoshinori
Y
Sakurai
Akira
A
Maruhashi
Koji
K
Ono
D000818:Animals; D001895:Boron / Q000493:pharmacokinetics*; D016754:Boron Neutron Capture Therapy / Q000379:methods; D002294:Carcinoma, Squamous Cell / Q000378:metabolism* / Q000532:radiotherapy*; D004307:Dose-Response Relationship, Radiation; D005720:Gamma Rays; D007554:Isotopes / Q000493:pharmacokinetics; D008657:Metabolic Clearance Rate / Q000528:radiation effects; D051379:Mice; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics
D007554:Isotopes; D019275:Radiopharmaceuticals; D001895:Boron