Radiotherapy is effective for most cases of
spinal cord compression. Although 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 question, we reviewed patients at the Mayo Clinic between 1975 and 1992 undergoing two or more courses of
radiotherapy to the same segment of the spinal column with radiographically documented epidural disease at the time of
reirradiation to determine outcome as measured by the ability to walk and by survival. Fifty-four patients met the study criteria. 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 reirradiated 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%) were ambulatory at the end of
reirradiation. Thirty-seven patients (69%) remained ambulatory at their last follow-up 6 days to 80 months following
reirradiation (median, 4.7 months). Five patients eventually became nonambulatory 6.5 to 35 months following
reirradiation. Median survival for all patients following
reirradiation was 4.2 months. We conclude that for
cancer patients with progressive epidural disease following
radiotherapy,
reirradiation frequently preserves ambulation and carries minimal risk of radiation
myelopathy during the patients' lifetime.