A comparison in individual murine tumors of techniques for measuring oxygen levels

Purpose: To investigate the relationship between different techniques for m easuring oxygen levels in a murine tumor model. Methods and Materials: Using the murine fibrosarcoma line KHT-C, five techn iques of measuring oxygen levels-the Eppendorf pO(2), Histograph, EFS bindi ng, the comet assay, a paired survival assay, and an in vivo growth delay a ssay-were assessed. In these experiments, three or more techniques were app lied in different combinations to measure the oxygen levels in individual t umors. Results: Statistically significant correlations were observed between the h ypoxic proportions calculated from the paired survival assay with those fro m EF5 binding. The comet assay was found to have a statistically significan t correlation with the paired survival analysis and the growth delay analys is. No statistically significant correlation was found between the Eppendor f pO(2), Histograph measurements and those from the other techniques, altho ugh there were weak correlations with the paired survival assay and EF5 bin ding. For technical reasons, a comparison was not made between EF5 binding and the growth delay assay, Conclusions: The correlations found between EF5 binding and the comet assay with the radiobiological assays suggest that these techniques have potenti al for predicting outcome following radiation treatment. The lack of correl ation seen between the pO(2), Histograph data and the radiobiological assay s is in contrast to results from early clinical trials. (C) 1999 Elsevier S cience Inc.