MICROREGIONAL BLOOD-FLOW IN MURINE AND HUMAN TUMORS ASSESSED USING LASER-DOPPLER MICROPROBES

A multichannel laser Doppler system has been used to measure microregi onal fluctuations in perfusion in the HT29 human tumour xenograft and in patients with advanced malignant disease. A comparison is made with previously obtained data for the SaF, a transplantable murine tumour. The 300 mu m diameter probes recorded fluctuations in erythrocyte flu x in tumour microregions with an estimated volume of 10(-2) mm(-3). Of the 66 human tumour microregions sampled, 26% showed a change in eryt hrocyte flux by a factor of 2 or more over the 60 min measurement peri od, compared with 37% of HT29 and 48% of SaF microregions. In each of the studies more than 50% of changes were completed within 20 min, alt hough slower changes were more common in the human rumours than in the experimental systems. Within the Ih monitoring period at least 30% of the changes were reversed (human rumours 30%, HT29 45%, SaF 31%). The se findings demonstrate that microregional changes in erythrocyte flux , consistent with transient, perfusiondriven changes in oxygenation, a re a feature of human malignancies as well as experimental transplante d tumours.