[Hypoxia-radiotherapy: the changes in selected physiological parameters of healthy tissue during the breathing of a hypoxic gas mixture].

摘要: BACKGROUND Chronic hypoxia in tumors is generally accepted to be one of the most important factors concerning sensibility irradiation. The principle hypoxyradiotherapy achieve a limited (maximal 30 min) radioresistance healthy (actually euoxic) tissue by acute aerogen hypoxia, without protecting effects average chronic hypoxic tumor. This study investigates changes selected physiological parameters vivo during hypoxia. PATIENTS AND METHODS In 31 persons (group A) we documented blood-gas-analysis, ECG-parameters, blood pressure and pulse lasting 5 minutes. During minutes determined another 10 B) relations between different phosphoryl-metabolites means 31-phosphorus magnetic resonance spectroscopy (31P-MRS). 31P-MRS Musculus triceps surae was performed on our 1.5 T imaging system (Magnetom, Siemens) using 8 cm diameter surface coil. To condition tested, gas-mixture with 8.2% O2 used. RESULTS group A led significant O2-pressure, O2-saturation frequency. pO2-values drop 5th minute about 50% initial value. Concerning B phosphoryl metabolites show no CONCLUSIONS results an excellent tolerability breathing gas-mixture, confirm that this mixture containing ensures decrease pO2-levels more than 50%. necessary dose modifying factor (DMF) at least 1.15 1.2. seem reflect ability adapt conditions starting after leading loss radioprotective effect