Review of Stereotactic Radiosurgery for Intramedullary Spinal Lesions

Abstract

Stereotactic radiosurgery (SR) represents an increasingly utilized modality in the treatment of intracranial and extracranial pathologies. Stereotactic spine radiosurgery (SSR) uses an alternative strategy to increase the probability of local control by delivering large cumulative doses of radiation therapy (RT) in only a few fractions. SSR in the treatment of intramedullary lesions remains in its infancy - this review summarizes the current literature regarding the use of SSR for treating intramedullary spinal lesions. Several studies have suggested that SSR should be guided by the principles of intracranial radiosurgery with radiation doses placed no further than 1-2mm apart, thereby minimizing exposure to the surrounding spinal cord and allowing for delivery of higher radiation doses to target areas. Maximum dose-volume relationships and single-point doses with SSR for the spinal cord are currently under debate. Prior reports of SR for intramedullary metastases, arteriovenous malformations, ependymomas, and hemangioblastomas demonstrated favorable outcomes. In the management of intrame- dullary spinal lesions, SSR appears to provide an effective and safe treatment compared to conventional RT. SSR should likely be utilized for select patient-scenarios given the potential for radiation-induced myelopathy, though high-quality literature on SSR for intramedullary lesions remains limited.