HM-PAO assessment of human tumour perfusion

Technetium-99m-labelled hexamethylpropylene amine oxime (HM-PAO) has been used to investigate tumour perfusion in 11 tumour sites in 8 patients with a variety of histologies. In 8 out of 11 instances single photon emission tomography clearly distinguished between tumour and normal tissues; in 7 cases due to increased HM-PAO uptake and in 1 due to reduced tumour uptake compared with hepatobiliary excretion of HM-PAO in adjacent normal liver. Heterogeneous uptake within individual tumour masses was observed in 3 cases. In 2 where a correlation between the pathology of excised tumour and the scan findings could be made, the findings were consistent with HM-PAO uptake in well-perfused tissue. These preliminary observations suggest that Technetium-99m-HM-PAO may be a valuable clinical technique for displaying patterns of tumour perfusion.