Re-resection with brachytherapy for locally recurrent soft tissue sarcoma arising in a previously radiated field

The use of further radiotherapy among patients with soft tissue sarcoma that recurs in a previously irradiated area is controversial. Presented is a review of our 7-year experience with brachytherapy for recurrent soft tissue sarcoma.

A retrospective review was performed of 26 patients who underwent perioperative brachytherapy between 1990 and 1997 for recurrent soft tissue sarcoma. In all cases, the sarcoma recurred within a previously irradiated field. After-loading brachytherapy catheters were placed at the time of surgical extirpation of the sarcoma within a single-plane implant by use of 1-cm intercatheter spacing. Insertion of the radioactive 192Ir wire was delayed until the fifth to seventh postoperative day to allow initial wound healing. The prescribed dose rate for the 192Ir wire ranged between 50 and 80 cGy an hour, and the dose was specified at 0.5 cm from the plane of the implant. The anatomic locations treated included lower extremity (N = 10), upper extremity (N = 7), trunk (N = 7), and head and neck (N = 2).

Total tumor extirpation, confirmed by negative frozen section margins, was accomplished in all cases. The mean dose of external-beam irradiation received before brachytherapy was 55.6 Gy +/- 1.8 Gy (range, 30.0 to 70.3 Gy). The mean dose of radiation prescribed at the implant procedure was 47.2 Gy +/- 1.6 Gy (range, 11.0 to 50.0 Gy). A tissue transfer flap was placed over the bed of resection in 13 cases. Complications occurred in five patients including, three with wound breakdown, one with osteonecrosis, and with neuralgia. Operative intervention was required in four of the five patients with complications; each of the patients requiring operative intervention for wound-related complications had undergone primary wound closure without tissue transfer. Recurrence of disease occurred in 13 patients: nine local and four distant metastases. The median follow-up was 16 months (range, 2 to 73 months). The 5-year local recurrence-free, distant recurrence-free, disease-free, and overall survival rates after brachytherapy were 52%, 75%, 33%, and 52%, respectively.

Re-irradiation of recurrent soft tissue sarcoma by brachytherapy in conjunction with resection can be performed with acceptable complication rates. Local control can be achieved for the majority of patients who would otherwise require more radical surgical procedures.