Abstract
Xe clearance measurement is available in clinical practice to know the blood flow of tumor to some extent. Yoshida ascite tumor cells were trnsplanted in the subcutane of Donryu rat. Correlation between tumor size, Xe cleance, and tumor capillary pattern was investigated with regard to irradiation. Tumor smaller than 1 cm in diameter revealed good blood flow as well as. homogenously distributed capillary. However that of more than 2 cm contained necrotic lesion in its center without capillary. In accordance with this clearance from the center was badd contrary to that from the periphery which was good.
Tumors of 2 cm in size irradiated with various single dose or f ractionted dose. The time required to reduce the tumor size to 1 cm was dependent to dose or fractionation. However these 1 cm tumors were worse than non-irradiated 1 cm tumor in blood flow as well as in capillary distribution in the center. These findings strongly suggested the parallelity of blood flow and capillary distribution.
