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 discouraging results have led to trials of various adjuvant therapies. Some studies suggest a role for radiation in improving regional control. Radiation doses, however, are limited by the tolerance of abdominal organs. Methods: Between 1985 and 1989, the Radiation Therapy Oncology Group 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. Patients underwent maximal surgical resection (subtotal or total gastrectomy and regional node dissection) and IORT doses of 12.5-16.5 Gy were delivered in 27 patients. Adjuvant external beam radiation was given to 23 of the 27 patients with total doses ranging from 24 to 50 Gy. Results: 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 only 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 surgical resection and postoperative radiotherapy appears to be feasible without excessive morbidity in a multiinstitutional study. Its ultimate value requires further study.