Experience with twice-a-day fractionation in clinical radiotherapy.

Theoretical reasons have led to the treatment of 24 patients with advanced, rapidly growing squamous cell carcinomas of the head and neck, and 17 patients with inflammatory carcinoma of the breast with twice-a-day fractionation. After initial reduction in dose in both series, acute reactions and sequelae are similar to those in conventionally treated patients. The relative control rates are better than would be expected from conventional irradiation.