Primary spinal cord tumors treated with surgery and postoperative irradiation

Between 1954 and 1979, 37 patients with a primary spinal cord tumor received postoperative irradiation after laminectomy. There were 26 intramedullary and 11 tumors of the conus/cauda equina. The 26 intramedullary tumors were divided as follows: 14 astrocytomas, eight ependymomas, three unbiopsied tumors, and one diffuse histiocytic lymphoma. Of the cauda equina tumors, 10 were ependymomas and one was an astrocytoma. Patients were followed until death or for a minimum of 4 years. The 5- and 10-year actuarial survivals for the entire group were 70 and 58%, respectively. Anatomic location of the tumor was the most important predictor of both survival and neurologic function. Patients with tumors of the cauda equina had superior neurologic function and a significantly better survival than those with tumors at other sites. Recurrent tumor was the cause of death in 82% of the patients dead at the time of analysis. Of the patients alive at the conclusion of the study, 10 were completely normal or had only mild neurologic deficit; the remaining 10 patients were severely disabled. Increasing radiation dose correlated with an increase in tumor control and survival. Of those receiving less than 40 Gy, 77% died of recurrent tumor, while 83% of those who received greater than 40 Gy are alive 4.1 to 28.9 years after treatment.