Safety and Efficacy of Radiation Dose Delivered via Iodine-125 Brachytherapy Mesh Implantation for Deep Cavity Sarcomas

Radiation delivered as brachytherapy (BRT) via catheters placed during extremity soft tissue sarcoma (STS) resection results in acceptable local control rates; however, there are limitations in deep cavities. I-125 seeds embedded in mesh provide a flexible BRT platform that may be contoured to irregular deep cavities surfaces, but the risks and benefits are unknown. Patients with thoracic, abdominal, pelvic, retroperitoneal, and deep truncal STS undergoing resection and implantation of permanent I-125 mesh BRT at our institution were reviewed. Local recurrence rates within the tumor bed covered by mesh (in field) and postoperative complications were analyzed. Between 2000 and 2010, a total of 46 patients were treated for primary (n = 8, 17 %) or recurrent (n = 38, 83 %) deep cavity STS (median follow-up 34.8 months); 74 % received external-beam radiotherapy for this or a prior presentation. In-field recurrences were observed in 9 patients (19.5 %). Crude cumulative incidences of in-field, regional, and distant recurrences at 5 years were 26.3, 54.2, and 54.1 %, respectively. 5-year overall survival rate was 47.2 %; median survival was 44.0 months. Twenty-two patients (48 %) experienced complications, half of whom (24 %) developed grade III/IV complications requiring percutaneous intervention (n = 6) or reoperation (n = 5) at a median of 35.5 days. There were no postoperative deaths. To our knowledge, this is the first study to report safety and efficacy for permanent I-125 mesh BRT implantation after resection of deep cavity STS. Local in-field recurrence rates were relatively low in this high-risk population. However, 24 % developed complications requiring intervention. I-125 mesh BRT appears effective, but it should be used with caution.