Intraoperative radiation therapy for metastatic spinal tumors

Study Design. Retrospective examination of 37 pa tients with metastatic spinal tumors treated with intraoperative radiation therapy. Objective. To propose a new technique for local control of metastatic spinal tumors. Summary of Background Data. No reports of intraoperative radiation therapy for metastatic spinal tumors have been published as of the time of this writing. Methods. Between December 1992 and April 1996, intraoperative radiation therapy was performed in 37 patients with spinal metastasis. In all but one patient, the spinal cord was protected during intraoperative radiation therapy by a lead shield to prevent radiation myelopathy. In addition to intraoperative radiation therapy, 22 of the 37 patients received external radiation therapy, either before or after their operation. Although the authors had recommended a dose of approximately 30 Gy of external radiation therapy after wound suture removal to patients who did not receive preoperative radiation therapy, the remaining 15 patients did not receive external radiation therapy, either by choice or because they received alternative therapy. Adjuvant chemotherapy for various cancers was administered to 9 of the 37 patients, including 4 of the aforementioned 15. Results. All patients attained clinical improvement in pain, neurologic function status, or both, with no evidence of local recurrence. Radiation myelopathy developed in the one patient whose spinal cord was not protected during intraoperative radiation therapy. Eleven patients experienced metastasis in vertebrae that were not surgically treated. Conclusion. Intraoperative radiation therapy appears to achieve good palliation and may be useful for local control of spinal metastases.