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

Purpose: Only 50% of patients with retroperitoneal sarcomas undergo complete resection and of these, 47% develop local tumor recurrence. To determine whether irradiation with dose escalation improves locoregional control, we reviewed the experience with adjuvant radiotherapy in the treatment of retroperitoneal sarcomas at the Fox Chase Cancer Center and the Hospital of the University of Pennsylvania. Methods and Materials: 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 Pennsylvania between May 1965 and July 1992. Follow-up ranged from 14-340 months. Nineteen patients were treated postoperatively and 2 preoperatively. Radiation doses were between 36.0 Gy and 90.0 Gy (median 54.0 Gy). Results: The 2-year rates of local control and survival were 72% and 69%, respectively. Tumor size, stage, grade, and histology did not influence local control. Two of eight patients (25%) who received a total dose of > 55.2 Gy experienced local failure compared to 5 of 13 (38%) who received less than or equal to 55.2 Gy. One patient experienced a small bowel obstruction that required surgical intervention. There were no other severe complications. Conclusion: Postoperative treatment with radiotherapy using a dose > 55.0 Gy is recommended for patients with retroperitoneal sarcomas following surgical resection due to the significant likelihood of local recurrence. Innovative adjuvant radiation techniques to escalate doses to greater than 55.0 Gy including intraoperative radiation therapy, brachytherapy, or use of small bowel exclusion devices to reduce small bowel toxicity should be considered for retroperitoneal sarcomas.