Experimental Studies on the Possible Influence of Invasive Oxygen Measurements on Tumour Radiosensitivity

Abstract

The effects of tissue damage associated with invasive pO₂ measurements on radiation sensitivity were investigated using a xenografted squamous cell carcinoma model. For the tumour cure experiments, single dose irradiations were given following different regimens of polarographic pO₂ measurements associated with different degrees of mechanical tissue damage. With a dose of 32 Gy, 57% of animals were cured. Following 3 tracks of needle measurements, 73% of tumours were locally controlled, and 75% were cured after 8 needle tracks. The polarographic measurements gave virtually identical oxygenation data for recurrent or cured tumours (both median pO₂ 1.0 mmHg), respectively. There was thus no evidence of decreased radiosensitivity associated with tissue damage after invasive pO₂ measurements. The pre-therapeutic oxygenation status gave no evidence for a prediction of radiation response on an individual basis.