MEASUREMENT OF OXYGEN-TENSION IN TUMORS BY TIME-RESOLVED FLUORESCENCE

Tumour oxygenation is important in clinical radiotherapy because hypox ic cells are radioresistant. Knowledge of the stale of tumour oxygenat ion would be advantageous for maximising effectiveness of treatment. A prototype fibre optic fluorosensor for measuring low (radiobiological ly relevant) levels of oxygen is described. Based on oxygen quenching of the fluorescence of an excited fluorophor immobilised in a polymer at the end of an optical fibre, the sensor shows promise in overcoming some of the limitations of existing oxygen sensor systems. The protot ype fibre optic sensor operates most effectively in the 0-2% oxygen ra nge with fast response and settling times. Preliminary results from me asurements in tumours are presented.