Pelvic relapse following subtotal lymphoid irradiation in early stage Hodgkin's disease--an analysis of risk, management, and outcome.
PURPOSE: To evaluate the time of onset, method of identification, management, and outcome of pelvic relapse following subtotal lymphoid irradiation (STLI) alone (mantle and paraaortic/spleen or splenic pedicle fields, excluding the pelvis) in supradiaphragmatic Stage I-II Hodgkin's disease. METHODS AND MATERIALS: A retrospective analysis was performed of the initial, relapse, and regular follow-up evaluations of patients with pelvic relapse following STLI alone from 1968 to the present for supradiaphragmatic Stage I-II Hodgkin's disease after pathologic staging (PS-laparotomy staging) and clinical staging (CS-no laparotomy staging). RESULTS: Following staging, which included bipedal lymphangiography, 482 patients (408 PS and 74 CS), were treated with STLI alone for supradiaphragmatic Stage I-II Hodgkin's disease. The actuarial freedom from relapse at 20 years was 75% in PS patients and 81% in CS patients. The actuarial pelvic failure at 20 years was 7% for PS patients and 3% for CS patients. Of the 29 patients with pelvic relapse, 97% (28 of 29) occurred within 5 years of treatment, including 1 patient who progressed during initial treatment. Pelvic relapse was most commonly initially identified by abnormalities involving patient symptoms (62%), physical examination (55%), erythrocyte sedimentation rate (48%), and bipedal lymphangiogram and/or abdominal radiograph (38%). Relapse was limited to previously unirradiated sites in 17 patients (58%). In addition to pelvic lymph node disease, 3 patients (10%) had involvement of bone, and 4 patients (14%) had bone marrow involvement. Following relapse, all patients were treated with chemotherapy (MOP[P], MOP[P]/ABV[D], ABVD, or PAVe) and 19 of 29 patients received involved field consolidative irradiation. Twenty-one of 29 (72%) remained relapse free at the time of last follow-up evaluation, including 15 of 19 (79%) treated with combined therapy. Eight patients experienced a second relapse despite salvage therapy, and all eight expired with recurrent Hodgkin's disease. Two patients died of complications related to prior treatment. Therefore, the actuarial risk of death at 20 years associated with pelvic failure in the entire cohort of 482 patients was 2%. CONCLUSION: Pelvic relapse occurred in 7% of patients following STLI alone and was effectively diagnosed by regular follow-up, which included a combination of patient history, physical examination, and radiographic laboratory evaluation. Seventy-two percent of patients remained relapse free following salvage treatment, which included chemotherapy, resulting in an overall survival rate associated with pelvic control of 98%. This approach, therefore, spared the majority of patients the long-term risks associated with pelvic irradiation and/or chemotherapy, such as infertility, but maintained an excellent prognosis.