Optical sensor-based oxygen tension measurements correspond with hypoxia marker binding in three human tumor xenograft lines

Hypoxia has a negative effect on the outcome of radiotherapy and surgery an d is also related to an increased incidence of distant metastasis, In this study, tumor pO(2) measurements using a newly developed time-resolved lumin escence-based optical sensor (OxyLite((TM))) were compared with bioreductiv e hypoxia marker binding (pimonidazole), Single pO(2) measurements per tumo r were compared to hypoxia marker binding in tissue sections using image an alysis. Both assays were performed in the same tumors of three human tumor lines grown as xenografts, Both assays demonstrated statistically significa nt differences in the oxygenation status of the three tumor lines, There wa s also a good correlation between hypoxia marker binding and the pO(2) meas urements with the OxyLite((TM)) device, A limitation of the OxyLite((TM)) s ystem is that it is not yet suited for sampling multiple sites in one tumor . An important strength is that continuous measurements can be taken at the same position and dynamic information on the oxygenation status of tumors can be obtained, The high spatial resolution of the hypoxia marker binding method can complement the limitations of the OxyLite((TM)) system, In the f uture, a bioreductive hypoxic cell marker for global assessment of tumor hy poxia may be combined with analysis of temporal changes in pO(2) with the O xyLite((TM)) to study the effects of oxygenation-modifying treatment on an individual basis. (C) 2000 by Radiation Research Society.