A retrospective analysis of 33 primary intraspinal tumors treated with postoperative radiotherapy

Objective: To describe the clinical characteristics, outcome and prognostic factors of primary intraspinal tumor treated with postoperative radiotherapy. Methods: Thirty-three patients diagnosed as suffering from intraspinal tumor treated with postoperative radiotherapy were analyzed. There were eighteen male and fifteen female, with a median age of 37 years (range 7-64 years). Two patients were treated with grossly total resection, 25 subtotal resection, 2 biopsy only. These patients were treated either with 60Co (n=18, before 1998) or 6 MV-X ray (n=15, after 1998) to the total dose of 45-68 Gy. The overall response and survival rates were calculated by Kaplan-Meier method and the difference between groups was tested by the log-rank method. The prognostic factors related to the characteristics of patient, tumor, and treatment were determined. Results: The overall response, five-year and disease-free survival rate was 81.3%, 59.4% and 56.3%, respectively. By multivariate analysis, the histological type (P=0.039) and gender (P=0.049) had independent impact on the 5-year survival rate. Ependymoma had a better prognosis compared to other histological subsets and female gained more survival advantage over male. There was no close relationship between survival and other factors, such as age, extent of surgery, initial site, irradiation dose, or the interval between surgery and radiotherapy. Conclusions: Postoperative radiotherapy is safe and effective for primary intraspinal tumor. The histological type and gender are important prognostic factors of survival in primary intraspinal tumors. (authors)