Purpose: To determine the impact of postoperative radiation therapy (POXRT) on outcome in spinal cord gliomas.
Patients and methods: Data from 242 patients were collected retrospectively from six institutions using a standardized data sheet. Pathology specimens, when available, were centrally reviewed.
Results: A total of 183 patients were analyzed: 82 received surgery alone as initial treatment, whereas 101 had surgery and POXRT. Demographic, diagnostic, and treatment factors were analyzed for impact on progression-free (PFS) and overall survival (OS). PFS in ependymoma patients was 74%, 60%, and 35% at 5, 10, 15 years, respectively, and was significantly influenced by treatment type, race, age, tumor grade, and type of surgery on univariate analysis, with age being the only significant factor on multivariate analysis (MVA) (p = 0.01). OS of ependymoma patients was 91%, 84%, and 75% at 5, 10, and 15 years, respectively, and was significantly influenced by both complete resection (p = 0.04) and age (p = 0.03) on MVA. In astrocytomas, PFS was 42%, 29%, and 15% at 5, 10, and 15 years, and was significantly influenced by POXRT in low- and intermediate-grade tumors on MVA (p = 0.02). OS at 5, 10, and 15 years was 59%, 53%, and 32%, respectively, and was significantly influenced by grade on MVA (p < 0.01).
Conclusion: Postoperative radiation therapy reduced disease progression in low- and moderate-grade astrocytomas. In ependymomas, complete resection significantly influenced OS.