High dose rate interstitial brachytherapy in soft tissue sarcoma: Technical aspects and results

Background: Radiation is essential for function preservation in the managem ent of soft tissue sarcoma (STS). One of the advantages of brachytherapy is that it allows for specific localization of radiation dose to the tumor be d. We examined the results of our clinical experiences with immediate posto perative high dose rate (HDR) brachytherapy and external beam radiation tre atment (EBRT) for STS. Methods: A total of 17 patients (11 primary and six recurrent) between 1995 and 1999 were included in this review. The inclusion criteria for HDR and EBRT were as follows: (1) high-grade tumor, (2) low-grade tumor of greater than or equal to 10 cm, (3) recurrent tumor, (4) tumor abutting or invading critical structures and (5) positive margin. The catheters (six French) we re placed parallel to the long axis of the tumor with a 1-1.5 cm spacing in between. If necessary, muscle or gel-foam was placed over the critical str uctures to maintain a minimum space of 0.5 cm from the catheters. On postop erative day 6, patients received HDR (2-3 Gy/fraction x6, twice daily). Thr ee weeks later, patients received EBRT (total 36-60 Gy). The follow-up dura tion was between 13 and 60 months (median 31 months). Results: There was no local failure within the radiation field in any of th e patients. One patient required wound revision for delayed healing after b rachytherapy. During EBRT, most patients experienced only mild erythema (gr ade 1 or 2 skin reaction). In long-term follow-up, there were no patients w ith neuropathy or significant fibrosis. Conclusions: Our results suggest that immediate postoperative HDR with a to tal dose of 12-18 Gy over 3 days is an effective treatment combined with EB RT in the management of STS.