Background: The study analyses a standardized, risk-adapted radiotherapy for stage IE-IIE primary extranodal lymphoma of the stomach and bowel.
Methods: Sixty eight patients (31 females, 37 males, median age 56 years) were treated from 1987-1992 in 15 centers. Fifty six patients had gastric and 12 patients had bowel lymphomas. Gastric lymphomas (low or intermediate grade stage I-II: 38 patients/high grade stage I: 18 patients) were treated by whole abdominal irradiation (25/30 Gy), booster dose to involved field (30/40 Gy) and additional boost to macroscopic residual lymphoma (40/50 Gy). Surgery consisted of gastrectomy (19 patients), partial gastric resection (30) or biopsy (7). In 8/18 stage II patients, supradiaphragmal irradiation was added. In 10/12 patients with bowel lymphoma, segment resection was performed, two received biopsy only. Radiation doses equalled those used for gastric lymphoma:
Results: In 51/56 patients (91%) with gastric lymphoma, the recommended dose for whole abdominal irradiation was given. A total of 40/56 patients (71%) received the required dose to the upper abdominal region, in 22/56 patients (39%) a booster dose for residual disease was applied. Five-year overall survival was 87%, 5-year disease-free survival 84%. Of nine relapses, two were in the gastric stump of low grade patients after reinfection with Helicobacter pylori. Three infield, intraabdominal relapses were observed in intermediate and high grade lymphoma, all other relapses were outfield. Eleven patients experienced late toxicity (bowel obstruction after laparatomy and irradiation, four patients; chronic gastritis, three patients; asymptomatic left kidney atrophy, two patients; asymptomatic hepathopathia, two patients). In bowel lymphoma, 5-year disease-free survival was 65%.
Conclusion: This study demonstrates the high efficacy of risk-adapted radiotherapy in gastric lymphoma. In low grade gastric lymphoma, whole abdominal irradiation may be reduced in dose or omitted. Total gastrectomy does not improve results and should therefore be avoided if possible.