Spine Stereotactic Radiosurgery Provides Long-Term Local Control and Overall Survival for Benign Intradural Tumors.

BACKGROUND AND OBJECTIVES

The role of radiosurgery in the treatment of benign intracranial tumors is well established. However, there are limited long-term follow-up studies on outcomes after stereotactic radiosurgery (SRS) for benign intradural spinal tumors. In this article, we report a large single-institution experience in using SRS to treat patients with benign intradural tumors of the spine.

METHODS

Overall, 184 patients (55% female) and 207 benign intradural tumors were treated. The median patient age was 52 years (range: 19-93). Tumor histology included schwannoma (38%), meningioma (15%), neurofibroma (21%), hemangioma (9%), hemangioblastoma (8%), hemangiopericytoma (5%), and paraganglioma (4%). Thirty-four (16%) lesions underwent resection before radiosurgery. Twenty-three (11%) lesions were NF1-mutated. The median single-fraction margin dose was 14 Gy (range: 11-20), and the median multifraction margin dose was 21 Gy (range: 15-30).

RESULTS

The median follow-up was 63 months (range: 1-258). At last follow-up, tumors volumetrically regressed (15%), remained stable (77%), or locally progressed (8%, median: 20 months [range: 3-161]) after SRS. The 1-, 5-, and 10-year local control rates were 97%, 92%, and 90%, respectively. On multivariable analysis, the absence of the NF1 mutation ( P = .004, hazard ratio: 0.23, 95% CI: 0.08-0.63) and single-fraction SRS ( P = .007, hazard ratio: 0.24, 95% CI: 0.08-0.68) correlated with improved local control. The median overall survival was 251 months (range: 1-258), and 1-, 5-, and 10-year overall survival rates were 95%, 85%, and 70%, respectively. For patients with pre-existing symptoms, tumor-associated pain and neurological deficits were noted to improve or remain stable in 85% and 87% of cases, respectively. Adverse radiation effects included delayed myelopathy (1%), acute pain flare (9%), dermatitis (0.5%), dysphagia (0.5%), and dysphonia (0.5%).

CONCLUSION

With long-term follow-up, spine radiosurgery is a safe and effective treatment for benign intradural tumors. In carefully selected patients, even with an NF1 mutation, SRS is associated with a high likelihood of local tumor control.