COMPARING TECHNIQUES OF MEASURING TUMOR HYPOXIA IN DIFFERENT MURINE TUMORS - EPPENDORF PO(2) HISTOGRAPH, [H-3] MISONIDAZOLE BINDING AND PAIRED SURVIVAL ASSAY

Using five transplantable murine tumors (SCC-VII, B16F1, KHT-C, KHT-LP 1, RIF-1), measurements of tumor hypoxia have been made with two techn iques which have the potential to be used for assessing oxygenation in human tumors (the Eppendorf pO(2) Histograph and binding of [H-3]miso nidazole) and Rave been compared with an established radiobiological t echnique, the paired survival assay. There were significant difference s in the pO(2) measurements made in individual tumors both within and between the five different tumor types. Significant differences betwee n the tumor types were also found for the [H-3]misonidazole binding. A correlation was observed between the mean values of the hypoxic propo rtion as measured by the paired survival assay and the mean binding of [H-3]misonidazole as measured by both tumor activity in dpm/100 mg ti ssue (r = 0.94, P = 0.02) and the tumor-to-muscle activity ratio (r = 0.87, P = 0.06). No biologically significant correlation was seen betw een the mean values of the hypoxic proportion from anesthetized mice a s measured by the paired survival assay (range 20-58%) and the pooled Eppendorf pO(2) Histograph measurements made on groups of tumors. Thes e results with the Eppendorf pO(2) Histograph are similar to those rep orted by others. When both Eppendorf pO(2) Histograph measurements and paired survival measurements were made on the same individual KHT-C t umors, it was again found that there was no correlation between the tw o measurements of hypoxia. (C) 1996 by Radiation Research Society