Postoperative Radiation Therapy in the Soft-tissue Sarcoma

Kim, Yeon Shil; Jang, Hong Seok; Yoon, Sei Chul; Ryu, Mi Ryeong; Kay, Chul Seung; Chung, Su Mi; Kim, Hoon Kyo; Kang, Yong Koo

Abstract

PURPOSE: The major goal of the therapy in the soft tissue sarcoma is to control both local and distant tumor. However, the technique of obtaining local control has changed significantly over the past few decades from more aggressive surgery to combined therapy including conservative surgery and radiation and/or chemotherapy. We retrospectively analyzed the treatment results of the postoperative radiation therapy of soft tissue sarcoma and its prognostic factor. MATERIAL AND METHODS: Between March 1983 and June 1994, 60 patients with soft tissue sarcoma were treated with surgery and postoperative radiation therapy at Kang-Nam St. Mary's hospital. Complete follow up was possible for all patints with median follow up duration 50 months (range 6- 162 months). There were 28 male and 32 female patients. Their age ranged from 6 to 83 with a median of 44 years. Extremity (58%) was the most frequent site of occurrence followed by trunk (20%) and head and neck (12 %). Histologically malignant fibrous histiocytoma (23%), liposarcoma (17%), malignant schwannoma (12%) constitute 52% of the patients. Daily radiation therapy designed to treat all areas at a risk for tumor spread upto dose of 4500-5000 cGy. A shrinking field technique was then used and total 55-65 Gy was delivered to tumor bed. Twenty-five patients (42%) received chemotherapy with various regimen in the postoperative period.
RESULTS
Total 41 patients failed either with local recurrence or with distant metastasis. There were 29 patients (48%) of local recurrence. Four patients (7%) developed simultaneous local recurrence and distant metastasis and 8 patients (13%) developed only distant metastasis. Local recurrence rate was rather higher than of other reported series. This study included patients of gross residual, recurrent cases after previous operation, trunk and head andneck primary. This feature is likely explanation for the decreased local control rate. Five of 29 patients who failed only locally were salvaged by re-excision and/or re-irradiation and remained free of disease. Factors affecting local control include histologic type, grade, stage, extent of operation and surgical margin involvement, lymph node metastasis (p<0.05). All 21 patients who failed distantly are dead with progressive disease at the time of this report. Our overall survival results are similar to those of larger series. Actuarial 5 year overall survival and disease free survival were 60.4 %, 36.6% respectively. Grade, stage (being close association with grade), residual disease (negative margin, microscopic, gross) were significant as a predictor of survival in our series (p<0.05).
CONCLUSION
Combined surgery and postoperative radiation therapy obtained 5 year survival rate comparable to that of radical surgery.