(P037) Treatment of Prognostically Favorable Peripheral Nerve Sheath Tumors: A Single-Institution Experience

April 15, 2016

Both surgery and radiation are very well tolerated treatment regimens with limited and manageable toxicity in favorable patients. Outcomes in patients with peripheral nerve sheath tumors < 5 cm are promising.

Zaker H. Rana, MD, David Asher, MD, Martin Richardson, DABR, RSO, MS, Kelly Spencer, DABMP, MS, William H. McAllister IV, MD, Ronald Kersh, MD, FACR; Riverside Regional Medical Center; University of Virginia

PURPOSE: Peripheral nerve sheath tumors account for 5% to 10% of all soft tissue sarcomas. Recent data show that tumor diameter  < 5 cm and/or gross total resection reduces hazard for death. The aim of this study was to review presentation, acute toxicity, and morbidity associated with surgery and radiation in the treatment of these favorable peripheral nerve sheath tumors at our institution.

METHODS: We retrospectively reviewed the data of 27 patients treated at our institution from February 2010 to June 2015. Ten patients received stereotactic body radiation therapy (SBRT) in 4–6 fractions, 16 received gross total resections, and 1 received both surgery and radiation. Baseline characteristics gathered included race, age at diagnosis, body mass index (BMI), site, histology, grade, previous therapy, RT dose, duration of treatment, time to diagnosis, and presenting symptoms. Outcomes recorded focused on acute toxicities, local control, and overall survival. Toxicities were graded according to the Common Terminology Criteria for Adverse Events version 4.0.

RESULTS: The median age at diagnosis was 53 years (range: 20–87 yr), median BMI (body mass index, kg/m2) was 28.9, median interval from onset of symptoms to diagnosis was 10 months (range: 0–32 mo), and median tumor size was 2.8 cm (range: 1.3–4.7 cm). Presenting symptoms included 41% of patients with lumbosacral plexopathy, 19% with mononeuropathy, 11% with incidental finding on imaging, 11% with a vestibular disturbance, 7% with brachial plexopathy, 7% with a gait disturbance, and 4% with a hip deformity. Toxicities were low, with 89% of patients experiencing grade 0/1 toxicity and 11% experiencing grade 2 toxicity. The local recurrence rate was 21% after a median of 18 months. There was no significant difference in outcomes between surgical treatment and RT.

CONCLUSION: Both surgery and radiation are very well tolerated treatment regimens with limited and manageable toxicity in favorable patients. Outcomes in patients with peripheral nerve sheath tumors < 5 cm are promising.

Proceedings of the 98th Annual Meeting of the American Radium Society -americanradiumsociety.org