Preoperative radiotherapy for adult soft tissue sarcomas

Purpose/Objective: Retrospective evaluation of preoperative radiotherapy for soft tissue sarcomas in a single institution with respect to survival, distant metastases, limb conservation, local control, and treatment complications. Materials and Methods: Between 1978 and 1992, 142 adults with soft tissue sarcoma of the trunk or extremities were treated with curative intent with preoperative radiotherapy. Primary tumors were staged by the Musculoskeletal Tumor Society staging system, as were the final surgical margins. A dose of 50.4 Gy was delivered in 1.8-Gy fractions once a day (22 patients) or in 1.2-Gy fractions twice a day (120 patients). Surgical resection was performed 3 - 5 weeks after radiotherapy. Thirty-four patients received adjuvant chemotherapy. Minimum follow-up was 2 years. Outcomes were evaluated by multivariate analysis and the Kaplan-Meier (actuarial) method. Results: Absolute survival: 82% at 2 years, 64% at 5 years, 49% at 10 years. Distant metastasis: 22% at 2 years, 35% at 5 years, and 40% at 10 years. Metastasis to the lung was the primary mode of failure. Histologic grade and size of the primary tumor were prognostic for both survival and freedom from distant metastasis. For high-grade sarcomas, the rate of distant metastasis increased with increasing tumor size. Local control: 92% at 5 years, 88% at 10 years. The most significant predictive variables for local tumor control were the final surgical margins achieved and the use of adjuvant chemotherapy. When resection margins were intralesional, the probability of local control was only 78% at 5 years, compared with > 90% when margins were either marginal, wide, or radical. Functional limb conservation was achieved in 85% of the patients with extremity or limb-girdle tumors. Five patients had nonfunctional extremities because of late effects or complications of treatment. Late effects or complications: Risk was directly related to the maximum length of treatment fields. At 10 years, risk was 21% for fields < 31 cm, 25% for fields 32 - 46 cm, and 54% for fields > 47 cm. Conclusion: Preoperative radiotherapy achieved a high probability of local control, and thus limb conservation. Tumor grade and size were the most significant prognostic factors for distant metastasis and absolute survival. The risk of significant treatment complications or late effects correlated directly to the volume of soft tissue irradiated. Use of adjuvant chemotherapy correlated significantly with improved local control, but not with an improvement in freedom from distant metastasis or absolute survival