Intraoperative radiotherapy in retroperitoneal sarcomas. Final results of a prospective, randomized, clinical trial.

Thirty-five patients with surgically resected sarcomas of the retroperitoneum were enrolled in a prospective, randomized, clinical trial comparing 20-Gy intraoperative radiotherapy in combination with postoperative low-dose (35- to 40-Gy) external-beam radiotherapy with postoperative high-dose (50- to 55-Gy) external-beam radiotherapy alone. Chemotherapy with doxorubicin hydrochloride, cyclophosphamide (anhydrous), and methotrexate sodium was used for a portion of the trial. Fifteen patients who received intraoperative radiotherapy and 20 control patients were followed up for a minimum of 5 years (median follow-up, 8 years). Median survival times were similar for the group that received intraoperative radiotherapy (45 months) and the control group (52 months). There were no indications of benefit from adjunctive chemotherapy. The number of locoregional recurrences was significantly lower among those who received intraoperative radiotherapy (six of 15) than control patients (16 of 20). Patients who received intraoperative radiotherapy had fewer complications of disabling radiation-related enteritis (two of 15) than control patients (10 of 20), but radiation-related peripheral neuropathy was more frequent among those who received intraoperative radiotherapy (nine of 15) than among control patients (one of 20).