Regional blood flow in human tumours with special reference to the effect of radiotherapy.

Blood flow in 41 superficial tumour nodules, of which nine were lymphomas, nine anaplastic carcinomas and 23 differentiated malignomas was measured using the 133Xe-clearance method. The lymphomas showed statistically higher blood flow (38-4 ml./min/100 g) than anaplastic (11-4 ml./min/100 g) and differentiated tumours (13-7 ml./min/100 g). After one week of radiation treatment the mean blood flow in anaplastic carcinomas was higher than the initial value. After an interval following the end of the radiation treatment the circulation diminished significantly compared with that observed immediately at the end of radiotherapy. The size of the tumours did not correlate with the blood flow.