Radiation-induced myelopathy in long-term surviving metastatic spinal cordcompression patients after hypofractionated radiotherapy: a clinical and magnetic resonance imaging analysis

Background and purpose: Hypofractionated radiotherapy is often administered in metastatic spinal cord compression (MSCC), but no studies have been pub lished 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 radioth erapy between 1988 and 1997, 13 live patients (seven females, six males, me dian age 69 years, median follow-up 69 months) surviving for 2 years or mor e were retrospectively reviewed to evaluate RIM. All patients underwent rad iotherapy. 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 re gimen of 5 Gy x 3, 4 days rest, and then 3 Gy x 5. Only one patient also un derwent laminectomy. Full neurological examination and magnetic resonance i maging (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. I n 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 p araplegic and cystoplegic, and magnetic resonance images evidenced an ische mic injury in the irradiated area. The only patient treated with surgery pl us postoperative radiotherapy worsened and remained paraparetic. Magnetic r esonance 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 survivin g MSCC patients, we believe that a hypofractionated radiotherapy regimen ca n be used for the majority of patients. For a minority of patients, more pr otracted radiation regimens could be considered. (C) 2001 Elsevier Science Ireland Ltd. All rights reserved.