Of 34 evaluated patients with primary
spinal cord tumors, 32 were irradiated at our institutions between 1969 and 1983. The results are reported of 32 patients, 16 with
ependymoma and 16 with
astrocytoma, who were treated with postoperative external beam
radiotherapy following biopsy or subtotal resection. Twenty-nine patients received 45-55 Gy megavoltage beam irradiation in five to six weeks, and the remaining three patients received less than 40 Gy. The minimum follow-up was five years. Five- and ten-year actuarial survival rates for the entire group of patients were 73% (22/30) and 50% (8/16), respectively, including three patients who were salvaged by surgery after
radiotherapy failures. Corresponding five- and ten-year relapse-free survival rates were 60% (18/30) and 32% (6/19), respectively. Of the 29 patients who received more than 45 Gy, relapse-free survival at five years was 63% (17/27). Treatment failed in 13 patients, and all of those failures were within the irradiated portals. Patients with
ependymomas have significantly better relapse free survival than those with
astrocytomas, 80% vs. 40% (p less than 0.05). There was a significant difference in survival between patients with
tumors involving the cervical spine and those with
tumors in the other locations, 45% vs. 89% (p less than 0.05). There was no significant difference in survival between patients with cauda equina
tumors and those with
tumors of the spinal cord, 100% vs. 68% (p less than 0.05). No
radiotherapy-related neurological deficit was noted with a maximum 20 year follow-up. This study confirms that external beam
radiotherapy is a safe and effective treatment modality for primary
spinal cord tumors.