OUTCOME AFTER SPINAL REIRRADIATION FOR MALIGNANT EPIDURAL SPINAL-CORDCOMPRESSION

Radiotherapy is effective for most cases of spinal cord compression. A lthough recurrent spinal cord compression is a common problem, little is known about whether reirradiation preserves neurologic function and what risk of radiation myelopathy it carries. To investigate this que stion, we reviewed patients at the Mayo Clinic between 1975 and 1992 u ndergoing two or more courses of radiotherapy to the same segment of t he spinal column with radiographically documented epidural disease at the time of reirradiation to determine outcome as measured by the abil ity to walk and by survival. Fifty-four patients met the study criteri a. Radiation doses for the first course ranged from 2,250 to 5,400 cGy (median, 3,000 cGy), and total dose for all courses to the reirradiat ed spinal segment ranged from 3,650 to 8,089 cGy (median, 5,425 cGy). All patients were ambulatory following the first course of radiation, 40 (74%) were ambulatory at the onset of reirradiation, and 42 (78%) w ere ambulatory at the end of reirradiation. Thirty-seven patients (63% ) remained ambulatory at their last follow-up 6 days to 80 months foll owing reirradiation (median, 4.7 months). Five patients eventually bec ame nonambulatory 6.5 to 35 months following reirradiation. Median sur vival for all patients following reirradiation was 4.2 months. We conc lude that for cancer patients with progressive epidural disease follow ing radiotherapy, reirradiation frequently preserves ambulation and ca rries minimal risk of radiation myelopathy during the patients' lifeti me.