Background and purpose: Hypofractionated radiotherapy is often administered in metastatic spinal cord compression (MSCC), but no studies have been published on the incidence of radiation-induced myelopathy (RIM) in long-term surviving patients. Our report addresses this topic.
Patients and methods: Of 465 consecutive MSCC patients submitted to radiotherapy between 1988 and 1997, 13 live patients (seven females, six males, median age 69 years, median follow-up 69 months) surviving for 2 years or more were retrospectively reviewed to evaluate RIM. All patients underwent radiotherapy. Eight patients underwent a short-course regimen of 8 Gy, with 7 days rest, and then another 8 Gy. Five patients underwent a split-course regimen of 5 Gy x 3, 4 days rest, and then 3 Gy x 5. Only one patient also underwent laminectomy. Full neurological examination and magnetic resonance imaging (MRI) were performed.
Results: Of 12 patients submitted to radiotherapy alone, 11 were ambulant (eight without support and three with support) with good bladder function. In nine of these 11 patients, MRI was negative; in one case MRI evidenced an in-field relapse 30 months after the end of radiotherapy, and in the other, two new MSCC foci outside the irradiated spine. In the remaining patient RIM was suspected at 18 months after radiotherapy when the patient became paraplegic and cystoplegic, and magnetic resonance images evidenced an ischemic injury in the irradiated area. The only patient treated with surgery plus postoperative radiotherapy worsened and remained paraparetic. Magnetic resonance images showed cord atrophy at the surgical level, explained as an ischemic necrosis due to surgery injury.
Conclusions: On the grounds of our data regarding RIM in long-term surviving MSCC patients, we believe that a hypofractionated radiotherapy regimen can be used for the majority of patients. For a minority of patients, more protracted radiation regimens could be considered.