Initial results of a trial of preoperative external-beam radiation therapy and postoperative brachytherapy for retroperitoneal sarcoma

Background: Surgical resection alone does not cure the majority of patients with retroperitoneal sarcoma (RPS). We evaluated the effects of preoperative external-beam radiotherapy (XRT) and postoperative brachytherapy (BT) combined with complete surgical resection. Methods: Fifty-five patients with primary or locally recurrent RPS judged to be resectable were entered onto a trial of combined therapy and observed prospectively. Forty-six patients under-went complete gross resection with curative intent. Of these, 41 patients completed preoperative XRT and 23 patients received BT. Outcome measures were treatment toxicity, overall survival, and disease-free survival (DFS). Results: Preoperative XRT was very well tolerated and was associated with Radiation Therapy Oncology Group acute toxicity scores of less than or equal to2 in all patients. Acute postoperative and BT-related toxicity resulted in modified RTOG scores of greater than or equal to3 in 39.1% (18 of 46) of patients. Late toxicity was associated with death in 4.3% (2 of 46) and with life-threatening illness in 2.2% (1 of 46) of patients, all of whom had been treated with BT to the upper abdomen. The 2-year overall survival and DFS for resected RPS were 88% and 80%, respectively. Significantly better 2-year DFS was achieved in patients with primary RPS and in those with low-grade tumors (93% and 95%, respectively). Conclusions: The initial results of combined therapy are promising. Although preoperative XRT was very well tolerated, BT to the upper abdomen was associated with substantial toxicity. Our current protocol includes selective application of BT to the lower abdomen only.