Effects of single-dose irradiation in tumor blood flow studied by 15O decay after proton activation in situ.

Abstract
A noninvasive technique employing photon activation of tissue oxygen in situ and detection of subsequent 15O positron decay was used to study the effects of single-dose 60Co irradiation on capillary blood flow in transplanted rat rhabdomyosarcomas. Tumor blood flow was measured before irradiation with 16.5, 38.5 or 60.5 Gy [gray] and at several intervals afterward (0-72 h). Pre-irradiation values of volume-averaged blood flow in the tumor ranged from 7-44 ml/min/100 g. Several hours after irradiation, blood flow fell by up to 50% for 60.5 Gy and up to 35% for 16.5 Gy. However, 24 h after irradiation, tumor blood flow had recovered completely in the 16.5-Gy group and substantially in the others. For smaller doses such as the fractions typically employed in radiotherapy, no changes in tumor blood flow were observed.

This publication has 0 references indexed in Scilit: