Single-Fraction Spine Stereotactic Body Radiation Therapy for the Treatment of Chordoma.

PURPOSE: Chordoma is a radioresistant tumor that presents a therapeutic challenge with spine involvement, as high doses of radiation are needed for local control while limiting dose to the spinal cord. The purpose of this study is to determine the efficacy and safety of single-fraction spine stereotactic body radiation therapy for the treatment of spine chordoma. METHODS: A retrospective review of our institutional database from 2006 to 2013 identified 8 patients (12 cases) with chordoma of the spine who were treated with spine stereotactic body radiation therapy. Surgical resection was performed in 7 of the 12 cases. The treatment volume was defined by the bony vertebral level of the tumor along with soft tissue extension appreciated on magnetic resonance imaging fusion. Medical records and imaging were assessed for pain relief and local control. Treatment toxicity was evaluated using Common Terminology Criteria for Adverse Events version 4.0. RESULTS: Median age was 59 years (range, 17-91). Median target volume was 48 cm3 (1-304), and median prescription dose was 16 Gy (11-16). Median conformality index was 1.44 (1.14-3.21), and homogeneity index was 1.12 (1.05-1.19). With a median follow-up time of 9.7 months (.5-84), local control was achieved in 75% of the cases treated. One patient developed limited grade 2 spinal cord myelopathy that resolved with steroids. There were no other treatment toxicities from spine stereotactic body radiation therapy. CONCLUSION: Single-fraction spine stereotactic body radiation therapy can be safely delivered to treat chordoma of the spine with the potential to improve pain symptoms. Although the early data are suggestive, long-term follow-up with more patients is necessary to determine the efficacy of spine stereotactic body radiation therapy in the treatment of chordoma of the spine.

Gamma Knife radiosurgery in the management of brainstem metastases.

BACKGROUND: Metastases to the brainstem portend a poor prognosis and present a challenge in clinical management. Surgical resection is rarely a viable option. METHODS: Post-treatment MRI scans of patients with brainstem metastases treated with radiosurgery were used to determine local control and disease progression. Median survival was calculated using Kaplan-Meier analysis. Univariate and multivariate analyses were performed using log-rank test and Cox proportional hazards model, respectively. RESULTS: Thirty-two consecutive patients with brainstem metastasis underwent Gamma Knife radiosurgery. Median age was 50 years. Median tumor volume was 0.71 cm3 and median tumor margin dose was 13 Gy. Seventeen of 32 patients received WBRT prior to stereotactic radiosurgery. Median survival was 5.2 months. There was a statistically significant difference in survival based on RTOG recursive partition analysis (RPA) class. Median survival of patients categorized as RPA class I was 19.2 months, RPA class II was 8.4 months, and RPA class III was 1.9 months. The overall local tumor control rate was 87.5%. There were no acute complications following stereotactic radiosurgery and no evidence of radiation necrosis noted on post-treatment MRI scans. CONCLUSION: Stereotactic radiosurgery is an effective treatment for brainstem metastases and should be considered especially for patients with good performance status.