MEASUREMENT OF TUMOR OXYGENATION - A COMPARISON BETWEEN POLAROGRAPHICNEEDLE ELECTRODES AND A TIME-RESOLVED LUMINESCENCE-BASED OPTICAL SENSOR

A novel oxygen sensor which does not rely on electrochemical reduction has been used to measure the oxygenation of the murine sarcoma F in a comparative study with an existing polarographic electrode that is av ailable commercially. The prototype luminescence sensor yielded an oxy gen distribution comparable with readings made using a pO(2) histograp h. The percentage of regions detected that had a pO(2) less than 5 mm Hg was 79 and 75 using the Eppendorf pO(2) histograph and the luminesc ence fiber optic sensor, respectively. These values were compatible wi th a measured radiobiologically hypoxic fraction of 67% in this tumor. The polarographic method detected more regions with a pO, of 2.5 mm H g or less (69%) compared with the optical sensor (50%) (P < 0.05). Thi s could reflect differences in the oxygen use of the sensing devices. This initial assessment indicates the potential of a fiber-optic-based oxygen-monitoring system. Such a system should have several advantage s including monitoring temporal oxygen changes in a given microregion and use with NMR procedures. (C) 1997 by Radiation Research Society.