NTCT-08STEREOTACTIC RADIOSURGERY (SRS) FOR SPINAL METASTASES: A COMPLICATION PROFILE OF VERTEBRAL BODY FRACTURE. ANALYSIS OF 79 CASES

Abstract

Radiation treatment of spinal and paraspinal tumors has been limited by the tolerance of the spinal cord. Radiosurgery uses a stereotactic approach to deliver a conformal, high radiation dose to a localized target thereby increasing the likelihood of successful tumor control while minimizing radiation damage to the spinal cord. Since the first description of LINAC-based spinal SRS, multiple centers have reported their experience with emphasis on tumor and pain control. Recently reports on side effects and complications, including myelopathy and vertebral body fractures, were published. In this study, we summarize the risk of developing vertebral body fractures after the use of SRS for spinal metastases. This is a (IRB-approved) retrospective review of patients with metastatic lesions, who were treated with SRS between November 2007 and October 2014 in our institution. We performed a neuro-radiological imaging review and compared data sets before and after the treatment. Patients were grouped for pre-existing and newly developed vertebral fracture occurring after the SRS treatment. 79 patients were treated by SRS for spinal metastases during the study period; we collected data for 67 spinal segments with sufficient follow up data. Mean age was 61 years (25-80 years). Distribution according to spinal segments: cervical (8.7%), thoracic (40.6%), lumbar (43.5%) and sacral (7.2%). Mean prescription dose: 17.52Gy (8-25Gy) in mean 1.7(1-5) fractions. Mean maximal dose was 21.56Gy and mean peripheral dose was 15.51Gy.We noted new vertebral fracture in 18 cases (26.1%), mean time for follow up imaging 5 months (±7.1months). No patient was symptomatic from the fracture or needed a spinal fixation. The overall mean survival was 25.86 months (±19.83months). Spinal SRS is an effective palliative procedure with a low morbidity profile. Yet spinal fractures occur after the radiation treatment relatively commonly and patients therefore require active surveillance for this side effect.