MODULATION OF TOXICITY FOLLOWING EXTERNAL-BEAM IRRADIATION PRECEDED BY HIGH-DOSE-RATE BRACHYTHERAPY IN INOPERABLE ESOPHAGEAL CANCER

To induce fast relief of dysphagia in inoperable oesophageal cancer, w e applied high-dose rate (HDR) intraluminal irradiation followed by ex ternal irradiation (EBRT) in a phase II study. 15 patients (group A: n = 15; 10 men, 5 women; median age 66 years) were treated with 10 Gy H DR brachytherapy plus 40 Gy EBRT (15 fractions of 2.67 Gy). Severe sid e-effects were encountered in 60% of patients: 3 late ulceration, 2 pe nding fistula, 2 fistula and 2 patients with fatal haemorrhage after a n interval of 6 months. Overall response was excellent: 9 complete rem issions (60%) and 6 partial responses (40%). Because of the high toxic ity rate, in a subsequent study (group B: n = 30; 23 men, 7 women; med ian age 66 years) the EBRT scheme was changed using smaller fractions (2.0 Gy) to reach the same total dose of 40 Gy. The complication rate (17%) was significantly reduced, while the overall response remained e xcellent (83%): 17 complete and 8 partial responses. The impressive ch ange in complication rate of HDR brachytherapy and EBRT stresses the i mpact of the fraction per dose and illustrates the small therapeutic m argins. Copyright (C) 1996 Elsevier Science Ltd