Analysis of failures after whole abdominal irradiation in gastrointestinal lymphomas. Is prophylactic irradiation of inguinal lymph nodes required?

Background: To evaluate failures and to investigate the need for prophylactic inclusion of the inguinal lymph nodes in case of whole abdominal irradiation in gastrointestinal lymphoma. Patients and Method: In October 1992 a prospective study on primary gastrointestinal lymphoma was initiated to evaluate management strategies. Treatment consisted either of conservative management comprehending radiotherapy±chemotherapy or radio-/chemotherapy sequential to primary surgery, depending on the physician's decision. Until November 1996, 382 patients were enrolled. Out of them we analyzed 92 patients who received a whole abdominal irradiation, in 21 cases with prophylactic inclusion, in 71 cases without inclusion of the inguinal lymph nodes. Results: After a median follow-up time of 36 months in 92 patients with whole abdominal irradiation 9 patients developed relapse of gastrointestinal lymphoma (8 local failures, 2 distant failure). In these cases the analysis of radiation therapy shows low tumor doses or small field sizes. No significant difference in the relapse rates is shown between the 21 patients with inclusion of the inguinal lymph nodes in the abdominal radiation fields (3 recurrences ≅14,3%) and the 71 patients without enclosure of the inguinal lymph nodes (6 recurrences ≅8.5%). Conclusion: General prophylactic enclosure of the inguinal lymph nodes in the case of whole abdominal irradiation in gastrointestinal lymphoma seems to be unnecessary. (orig.)