Modification of glucose metabolism in radiation-induced brain injury areas using cervical spinal cord stimulation.

PURPOSE: Radiation-induced brain injury (RBI) is an insidious side-effect of radiotherapy mediated by vascular alterations, inflammation and ischaemia. In previous studies we had shown potential increases in loco-regional blood flow and glucose metabolism in brain tumours by using electrical cervical spinal cord stimulation (SCS). In this preliminary report we demonstrate the effect of cervical SCS on RBI-tissue metabolism, as assessed using [(18)F]fluorodeoxyglucose-positron emission tomography (FDG-PET). METHODS: SCS devices were inserted in eight patients with diagnosis of potential RBI in previously irradiated areas. While the SCS device was deactivated, each patient underwent an initial FDG-PET study to evaluate the clinical status. A second FDG-PET study was performed later the same day while the SCS device was activated in order to evaluate the effect of cervical SCS on glucose metabolism. RESULTS: Basal glucose metabolism in RBI areas was 31% lower than peri-RBI areas (p = 0.009) and 32% lower than healthy contra-lateral areas (p = 0.020). There was a significant increase in glucose uptake during SCS in both the RBI (p = 0.005) and the peri-RBI (p = 0.004) areas, with measured increases of 38 and 42%, respectively. The estimated potential maximal residual activity of the first FDG dose's contribution to the activity on the second scan was

Effect of cervical spinal cord stimulation on cerebral glucose metabolism.

OBJECTIVE: Syndromes resulting from decreased cerebral blood flow and metabolic activity have significant clinical and social repercussion. However, treatment options are limited. Cervical spinal cord stimulation has shown clinical benefit in the management of several ischemic syndromes. The aim of this report was to assess the effect of cervical spinal cord stimulation on cerebral glucose metabolism. MATERIALS AND METHODS: Between April 2000 and December 2005, 16 patients with brain tumors were assessed. Before and during spinal cord stimulation, they had cerebral glucose metabolism evaluated using 18fluoro-2-deoxyglucose positron emission tomography (18FDG-PET) in the healthy cerebral hemisphere contralateral to the lesion area. RESULTS: Following cervical spinal cord stimulation, there was a significant (p<0.001) increase in glucose metabolism in healthy cerebral hemisphere. The measured increase was 37.7%, with an estimated potential maximal contribution of the first 18fluoro-2-deoxyglucose injection to the quantification of the second positron emission tomography study (carry-over effect)

Modification of glucose metabolism in brain tumors by using cervical spinal cord stimulation.

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.

Fluorodeoxyglucose-positron emission tomography imaging versus sentinel node biopsy in the primary staging of melanoma patients.

BACKGROUND: Positron emission tomography (PET) imaging is superior to conventional techniques for the evaluation of patients with stage III and stage IV cutaneous melanoma. Several studies have highlighted the advantages of this noninvasive technique for the assessment of lymph node involvement. OBJECTIVE: To compare PET imaging with sentinel node biopsy for primary staging of cutaneous melanoma and to discuss the technical limitations of PET scanning. METHODS: Twenty-five consecutive patients with a histologic diagnosis of melanoma with a Breslow thickness equal or greater to 1 mm underwent a preoperative PET to assess lymph node involvement. RESULTS: Sentinel node biopsy and PET showed a sensitivity of 100% and 22%, respectively, in the identification of lymph node metastases. CONCLUSION: PET is not a sensitive technique for the primary staging of cutaneous melanoma.