MEASUREMENT OF HUMAN TUMOR OXYGENATION STATUS BY A POLAROGRAPHIC NEEDLE ELECTRODE - AN ANALYSIS OF INTERTUMOR AND INTRATUMOR HETEROGENEITY

Tumour oxygenation status was measured by a polarographic needle elect rode in 31 patients with lymph node metastasis of squamous cell carcin oma of the head and neck and 18 patients with primary soft tissue sarc oma. Two oxygenation parameters, the median pO(2) and the proportion o f measured values less than 5 mm Hg, were used in comparing the inter- and intrasubject heterogeneity in tumour and subcutaneous tissue. Res ults of the analysis may be summarized as follows: 1) the variation in oxygenation between tumours was significantly greater than that withi n tumours, 2) the variation in oxygenation of subcutaneous tissue betw een patients was significantly greater than the variation within patie nts, 3) oxygenation of tumour was significantly lower than that of sub cutaneous tissue, 4) no significant difference in the distribution of the oxygenation parameters in the two tumour types, and 5) both oxygen ation parameters correlated. In conclusion, measurements by oxygen ele ctrodes were able to distinguish intratumour heterogeneity from intert umour heterogeneity provided that several electrode tracks were done. The method therefore appears to be feasible for differentiation of tum our oxygenation clinically.