FDG PET hot spots predict better prognosis in spinal surgery patients

Doctors can now tell how effective a surgery for degenerative cervical myelopathy will be based on how much FDG is taken up by the cervical spinal cord, according to research published online August 5 in the Journal of Nuclear Medicine.

Frank W. Floeth, MD, from the department of neurosurgery at University of Dusseldorf in Dusseldorf, Germany, and colleagues evaluated patients with degenerative cervical spine stenosis for variations in glucose metabolism in areas of the cervical spine with F-18 FDG PET. Researchers found that hypermetabolism in this area prior to surgery was a direct indicator of better surgical outcomes.

“Focal glucose hypermetabolism at the level of cervical spinal cord compression may predict an improved outcome after surgical decompression,” wrote Floeth et al. “Thus, this finding on F-18 FDG PET suggests a functional damage in a reversible phase of cervical myelopathy.”

Decompressive surgery was performed for a total of 20 subjects with degenerative cervical stenosis and suspected spinal cord compression. Imaging data from both F-18 FDG PET and MRI were procured before surgery and after 12 months. Changes in FDG uptake were then compared to patient outcomes at follow up.

Results showed that spiked FDG uptake was seen in 10 subjects with stenosis prior to treatment. This dropped substantially after 12 months in conjunction with successful surgeries. Another 10 patients had insignificant uptake prior to surgery, but these levels still decreased in line with positive outcomes following treatment. 

“The focal hypermetabolism at the level of stenosis might be explained best by a compression-induced inflammatory response with intramedullary infiltration of glucose-consuming macrophages. This hypothesis was supported by recent evidence and provides a rationale for antiinflammatory medical treatment options, for example, corticosteroids to suppress the local hypermetabolism of glucose.”