Sample size
toxicity
This study is designed with four dose cohorts, starting at 50 Gy and going up to 80 Gy. The last cohort will consist of at least six patients. This means that the maximum number of patients (i.e., if in each cohort one dose-limiting toxicity occurs, see Design for details) will be (3 + 3) × 4 = 24 patients. The minimum number of patients will be two, which is when two patients in the first (50 Gy) cohort experience a dose-limiting toxicity. If during the entire study no patient experiences a dose-limiting toxicity, the number of patients will be 3 × 4 + 3 = 15.