Accelerated hyperfractionation for bronchogenic cancer: Radiation Therapy Oncology Group 9205

RTOG 92-05 was a phase II trial developed to evaluate the feasibility, toxicity, and acceptance of a three times daily accelerated hyperfractionation radiation therapy schedule delivering 110 cGy, three times daily, to 79.2 Gy uncorrected tumor dose in 72 fractions, in 24 treatment days, in patients with bronchogenic cancer. The radiographically visible tumor received accelerated hyperfractionation and the other radiation volume received standard hyperfractionation. Three times a day, a dose of 110 cGy was delivered, with an interfractional interval of 4 hours; the middle fraction was a gross tumor boost. This schedule allowed treatment to be completed in approximately 4 1/2 weeks in an effort to minimize repopulation, to have a better biologically modeled therapeutic ratio than other schedules that have been completed in cooperative groups, and to use doses within cooperative group experience. In 33 months 35 patients were entered into the study; 15 of the patients had squamous cell carcinomas, 10 had adenocarcinomas, 8 had large-cell undifferentiated carcinomas, and 2 had unspecified non-small-cell cancers. Nineteen patients had AJCC stage IIIB; 13, IIIA; 14, T4; 10, T3; 13, N2; and 7, N3. Twenty-one patients (60%) had greater than 5% weight loss. The Karnofsky performance status was 90 to 100 in 12 patients and 70 to 80 in 23 patients. Treatment was completed in 91% of patients. Acute toxicity >RTOG grade II occurred in three patients: one skin, one lung, and two esophagus (one each III and IV, the only grade IV in the study). Overall late toxicity > or = grade III occurred in six patients: three lung, one thyroid, one esophagus, and one subcutaneous tissue (all grade III). The median survival was 10.5 months, 1-year survival was 42%, and 3-year survival was 18%. The outcome in this group of patients with many adverse prognostic variables compared favorably to prior RTOG radiation-alone studies.