Hypermetabolism in 18F-FDG PET Predicts Favorable Outcome Following Decompressive Surgery in Patients with Degenerative Cervical Myelopathy

Abstract

The aim of this study was to prospectively assess the regional changes of glucose metabolism of the cervical spinal cord in patients with degenerative cervical spine stenosis and symptomatic cervical myelopathy after decompressive surgery using (18)F-FDG PET. Twenty patients with symptomatic degenerative monosegmental cervical stenosis with neuroradiologic signs of spinal cord compression underwent decompressive surgery. The clinical course using a functional status score (Japanese Orthopedic Association [JOA] score), (18)F-FDG uptake, and MR imaging were assessed before and at follow-up 12 mo after surgery. Pre- and postoperative changes of (18)F-FDG PET were correlated to the patients' clinical outcome. Ten patients demonstrated preoperatively a focally increased (18)F-FDG uptake at the level of the stenosis. At follow-up, the uptake declined significantly (P = 0.008), and a significant improvement of JOA scores (P < 0.001) could be observed. The remaining 10 patients were characterized preoperatively by an inconspicuous glucose uptake at the level of cord compression in combination with a poststenotic decrease of (18)F-FDG uptake. At follow-up, both JOA scores and (18)F-FDG uptake changed insignificantly. Focal glucose hypermetabolism at the level of cervical spinal cord compression may predict an improved outcome after surgical decompression. Thus, this finding on (18)F-FDG PET suggests a functional damage in a reversible phase of cervical myelopathy.