Hypoxyradiotherapy: lack of experimental evidence for a preferential radioprotective effect on normal versus tumor tissue as shown by direct oxygenation measurements in experimental sarcomas

摘要: Abstract Aim : In order to investigate possible pathophysiological mechanisms underlying the postulated preferential protective effect of hypoxia on normal tissue during radiotherapy, impact acute respiratory (8.2% O 2 + 91.8% N ) oxygenation was assessed. Methods Tumor and directly determined using -sensitive electrodes in two experimental rat tumors (DS Yoshida sarcomas) subcutis hind foot dorsum. Results During hypoxia, arterial blood tension (pO ), oxyhemoglobin saturation mean pressure decreased. Changes gas status were accompanied by a reflex hyperventilation leading hypocapnia alkalosis. subcutis, worsened with decreases median pO . Significant increases hypoxic fractions were, however, not seen. tumor tissues, also upon significant size for both sarcomas. Conclusion These results suggest that radiobiologically relevant reductions (and subsequent selective radioprotection) may be achieved. addition, models studied, worsening seen which could result an increased radioresistance.