ARCON: experience in 215 patients with advanced head and neck cancer

Abstract

Purpose: Hypoxia and tumor cell repopulation are radiation resistance mechanisms with proven clinical relevance in head and neck carcinomas. Randomized clinical trials have demonstrated the effectiveness of accelerated radiotherapy to counterbalance tumor repopulation. A next step to further improve treatment outcome is by combination of accelerated radiotherapy with hypoxia modifiers. Studies in mouse tumors showed significant sensitization when accelerated radiotherapy was administered together with carbogen breathing and nicotinamide to reduce chronic and acute hypoxia (ARCON). An enhancement ratio of 1.9 relative to conventionally fractionated radiotherapy alone was obtained with doses and fractionation schedules close to those used clinically.