TREATMENT OF ADENOCARCINOMA OF THE STOMACH WITH RESECTION, INTRAOPERATIVE RADIOTHERAPY, AND ADJUVANT EXTERNAL-BEAM RADIATION - A PHASE-II STUDY FROM RADIATION-THERAPY ONCOLOGY GROUP 85-04

Background: Fewer than 10% of patients presenting with adenocarcinoma of the stomach in the United States can expect to be cured. These disc ouraging results have led to trials of various adjuvant therapies. Som e studies suggest a role for radiation in improving regional control. Radiation doses, however, are limited by the tolerance of abdominal or gans. Methods: Between 1985 and 1989, the Radiation Therapy Oncology G roup conducted a phase II study to determine the feasibility of using intraoperative radiotherapy (IORT) in the treatment of adenocarcinoma of the stomach. Forty-three patients were entered into the study. Pati ents underwent maximal surgical resection (subtotal or total gastrecto my and regional node dissection) and IORT doses of 12.5-16.5 Gy were d elivered in 27 patients. Adjuvant external beam radiation was given to 23 of the 27 patients with total doses ranging from 24 to 50 Gy. Resu lts: Two-year actuarial survival in the 27 patients receiving IORT was 47% and median survival was 19.3 months. Disease-free survival was 27 %. Fifteen percent failed locally only, 26% with distant metastases on ly and 22% with both. Acute postoperative complications occurred in 14 % with one fatality. Severe late complications occurred in 7% with one fatality. Conclusions: Intraoperative radiotherapy combined with surg ical resection and postoperative radiotherapy appears to be feasible w ithout excessive morbidity in a multiinstitutional study. Its ultimate value requires further study.