Introduction: Soft tissue sarcoma has a high risk of local recurrence. Therefore, extensive surgical resection has been combined with radiotherapy to improve long-term results. Because external beam radiation doses may be limited by adjacent radiosensitive tissue, intraoperative boost radiation has been devised to achieve a higher total radiation dose in combination with external beam radiotherapy. We report our experience with this multimodal approach for primary and recurrent soft tissue sarcoma.
Methods: Clinical and pathological data were extracted from a prospective data base including all patients with a diagnosis of soft tissue sarcoma treated at the Department of Surgery, University of Heidelberg between 1988 and 1999. Intraoperative radiotherapy dosages were 12-15 Gy for the extremities and 15-18 Gy for the trunk and the retroperitoneum. Additional external beam radiotherapy was given at 40 Gy, whenever possible.
Results: Between 1988 and 1999, a total of 251 patients with primary or recurrent soft tissue sarcoma of the extremities, the trunk or the retroperitoneum were treated. The mean (+/- SD) age of 136 men and 115 women was 53+/-16 years. Five of 251 patients died post-operatively, giving a mortality rate of 2.0%. Intraoperative radiotherapy (IORT) was used in 92 patients (37%). Surgical complications were more frequent in IORT patients (30 of 92; 33%) compared to non-IORT patients (36 of 159; 23% P=0.1). Infectious complications were significantly more frequent in patients receiving IORT (P=0.03). Two hundred and four patients were macroscopically tumour-free (R0, R1 resection). For these patients multivariate analysis identified grading (relative risk (RR) 3.1-6.6; P<0.001), age (over 55 years; (RR) 1.8: P<0.008) and tumour location in the retroperitoneum (RR 2.2; P<0.004) as independently associated with recurrence-free survival. The use of IORT (P<0.02) reduced the relative risk of death or recurrence by 40% (RR 0.6; P<0.02). Sex, primary vs. recurrent tumour, T classification and R-status (R0 vs. R1) were not significantly related to recurrence-free survival.
Conclusions: In this prospective, non-randomized study of soft tissue sarcoma IORT was associated with a higher rate of infectious complications, but the the risk of death or recurrence was reduced by 40%.