The role of stereotactic body radiotherapy and stereotactic radiosurgery in the re-irradiation of metastatic spinal tumors

Abstract

Stereotactic body radiotherapy (SBRT) and stereotactic radiosurgery (SRS) are advanced radiotherapy delivery techniques that allow for the delivery of high-dose per fraction radiation. Advances in imaging technology and intensity modulation have allowed SRS and SBRT to be used for the treatment of tumors in close proximity to the spinal cord and cauda equina, in particular spinal metastases. While the initial treatment of spinal metastases is often conventional palliative radiotherapy, treatment failure is not uncommon, and conventional re-irradiation may not be feasible due to spinal cord tolerance. SBRT and SRS have emerged as important techniques for the treatment of spinal metastases in the proximity of previously irradiated spinal cord. Here we review the current data on the use of SBRT and SRS spinal re-irradiation, and future directions for these important treatment modalities.

Comparison of Surgical Outcomes Between Separation Surgery and Piecemeal Spondylectomy for Spinal Metastasis: A Retrospective Analysis

“…Although there have been many reports on total spondylectomy and separation surgery for spinal tumors (6,9,11,13,(18)(19)(20)(21)(22), most of them have focused on the single treatment modality. With the development of medical technology, the treatment strategies of metastatic spinal tumors have changed over the years.…”

Full automation of spinal stereotactic radiosurgery and stereotactic body radiation therapy treatment planning using Varian Eclipse scripting

“…First, the current state of the software used for automatic planning only provides options for de novo cases. However, it is not uncommon for patients undergoing spine SRS/SBRT to have already received palliative treatment at an earlier point in time 46 . Currently, we are working to incorporate that functionality, allowing the user to override the default dose limit to the spinal cord in terms of maximum dose allowed for the current plan or in terms of a combined biologically equivalent dose (BED).…”

“…However, it is not uncommon for patients undergoing spine SRS/SBRT to have already received palliative treatment at an earlier point in time. 46 Currently, we are working to incorporate that functionality, allowing the user to override the default dose limit to the spinal cord in terms of maximum dose allowed for the current plan or in terms of a combined biologically equivalent dose (BED). Second, the field setup using four co-planar full arcs and the mentioned collimation rotations, while used in this study and found to provide excellent dose shaping, is not a requirement.…”

Three discipline collaborative radiation therapy (3DCRT) special debate: The single most important factor in determining the future of SBRT is immune response

“…Trials are underway to evaluate SBRTs efficacy in other disease sites, including advanced lung cancer, pancreatic cancer, sarcoma, and oligometastatic disease. Stereotactic body radiotherapy is also an attractive option in a re‐irradiation setting for spinal, thoracic, and head and neck cancers …”