Object: In previous studies the authors have shown potential increases in locoregional blood flow and oxygenation in tumors by using electrical cervical spinal cord stimulation (SCS). In the present report they demonstrate the effect of cervical SCS on brain tumor metabolism, as assessed using [18F]fluorodeoxyglucose-positron emission tomography (FDG-PET).
Methods: Cervical devices were inserted in 11 patients who had high-grade gliomas, six of which had recurred. While the SCS device was deactivated, each patient underwent an initial FDG-PET study to clarify the clinical status. A second FDG-PET study was performed later the same day while the stimulation device was activated to determine the effect of cervical SCS on glucose metabolism. All 11 patients were invaluable for this PET study. Basal glucose metabolism was higher in the tumor than in the peritumoral areas (p = 0.048). There was a significant increase in glucose uptake during cervical SCS in both the tumor (p = 0.035) and the peritumoral (p = 0.001) areas, with measured increases of 43 and 38%, respectively. The estimated potential maximal residual activity of the first FDG dose's contribution to the activity on the second scan was 18.5 +/- 1% or less.
Conclusions: This PET study is the first in which is described the effect of cervical SCS on glucose metabolism in brain tumors and supports previous study data indicating a modification of locoregional blood flow and oxygenation by cervical SCS. These results open up new approaches to modifying the effect of radiochemotherapy in the treatment of malignant brain tumors.