Oncologic Surgery and Intraoperative Radiation Therapy (IORT) in Management of Unplanned Excision of Extremity Soft-Tissue Sarcoma (STS)

Abstract

Optimal management of patients with extremity STS treated with unplanned non-oncologic surgical excision is not clearly defined. We sought to investigate the efficacy and morbidity of limb-sparing oncologic re-resection with IORT for patients who previously underwent unplanned excision of extremity STS. A retrospective review identified twenty-two consecutively treated patients with extremity STS treated with IORT following oncologic limb-sparing surgery after an initial unplanned excision from September 2000 to July 2011. All patients had localized disease at the time of IORT. The median age was 36 years, with 8 patients (36%) under the age of 18. Tumor depth was superficial in 10 patients (45%) and deep in 12 patients (55%), and high grade tumors (Coindre grade 2-3) were found in 18 patients (81%). Close (<2mm) or positive margins at IORT were found in 6 patients (27%) and median tumor size was 2.6 cm (range 0.3 - 8.1 cm). The most common histologies were synovial sarcoma and fibrosarcoma (41% and 18%, respectively). The median IORT dose was 1250 cGy (range 1000-1500 cGy). Adjuvant external beam radiation therapy (EBRT) was given to 7 patients (32%) with a median dose of 5400 cGy (range 4500 - 6000 cGy), while no patient received EBRT prior to IORT. Perioperative chemotherapy was delivered to 4 patients (18%). The Kaplan-Meier product limit method was used to estimate disease control and survival and toxicity was reported according to CTCAE v4.0 guidelines. With a median duration of follow-up from surgery and IORT of 54.4 months (range 12 - 141 mos.), 3 patients developed a local recurrence with 1 patient subsequently undergoing amputation. The 5-year Kaplan-Meier estimates for local control (LC) were 84% (95% CI 58-95%); for amputation-free were 95% (95% CI 72-99%); for metastasis-free control (MFC) were 95% (95% CI 72-99%); for disease-free survival (DFS) were 79% (95% CI 52-92%); and for overall survival (OS) was 94% (95% CI 63-99%). Of evaluable patients, Grade 3 or higher acute (90 days or less from IORT) and late toxicities were reported for 3 (16%) and 4 (25%) patients, respectively. In all but one patient, observed toxicity improved or resolved. While oncologic re-resection is commonly employed, the timing and technique of radiation therapy in further management of unplanned extremity STS resection is less well established. Review of our institutional approach of oncologic limb-sparing re-resection in combination with IORT reveals excellent local control with acceptable morbidity. This technique offers a method of delivering focal therapy to achieve local control for the majority of patients, while obviating or allowing relatively reduced dose adjuvant EBRT.