A review of stereotactic body radiotherapy for the spine

Radiation therapy of the spine, as recourse for spinal tumours, is an effective method of achieving pain reduction and local control. Hypofractionated techniques like stereotactic body radiation therapy and especially stereotactic radiosurgery are quickly becoming more popular as studies are published demonstrating their superior outcomes. This review concerns aspects of spinal radiotherapy of interest to the clinical medical physicist, with a focus on stereotactic techniques. The literature surveyed is mostly from the last two decades, concentrating particularly on studies from the last few years. Clinical aspects of spinal disease are covered to give context to the development of different radiotherapy techniques and thus the changing suitability criteria of patients. The latest studies concerning the treatment pathway are reviewed and summarised-from simulation and prescription to contouring, treatment planning and treatment delivery. This then leads into a discussion of the accuracy and uncertainties surrounding different methods of immobilisation and image guidance. Treatment planning algorithms and approaches are also reviewed. Finally, we survey the most recent outcomes and statistics concerning failures, toxicity, survivability and control rates. With careful consideration of the latest literature, patients suffering from spinal disease have a good chance of positive outcomes following radiotherapy.