MANAGEMENT OF RETROPERITONEAL SARCOMAS - DOES DOSE-ESCALATION IMPACT ON LOCOREGIONAL CONTROL

Purpose: Only 50% of patients with retroperitoneal sarcomas undergo co mplete resection and of these, 47% develop local tumor recurrence. To determine whether irradiation with dose escalation improves locoregion al control, we reviewed the experience with adjuvant radiotherapy in t he treatment of retroperitoneal sarcomas at the Fox Chase Cancer Cente r and the Hospital of the University of Pennsylvania. Methods and Mate rials: Twenty-one patients with retroperitoneal sarcomas were treated with curative intent with surgical resection and radiation therapy at Fox Chase Cancer Center or the Hospital of the University of Pennsylva nia between May 1965 and July 1992. Follow-up ranged from 14-340 month s. Nineteen patients were treated postoperatively and 2 preoperatively . Radiation doses were between 36.0 Gy and 90.0 Gy (median 54.0 Gy). R esults: The 2-year rates of local control and survival were 72% and 69 %, respectively. Tumor size, stage, grade, and histology did not influ ence local control. Two of eight patients (25%) who received a total d ose of > 55.2 Gy experienced local failure compared to 5 of 13 (38%) w ho received less than or equal to 55.2 Gy. One patient experienced a s mall bowel obstruction that required surgical intervention. There were no other severe complications. Conclusion: Postoperative treatment wi th radiotherapy using a dose > 55.0 Gy is recommended for patients wit h retroperitoneal sarcomas following surgical resection due to the sig nificant likelihood of local recurrence. Innovative adjuvant radiation techniques to escalate doses to greater than 55.0 Gy including intrao perative radiation therapy, brachytherapy, or use of small bowel exclu sion devices to reduce small bowel toxicity should be considered for r etroperitoneal sarcomas.