Glucose corrected standardized uptake value (SUVgluc) in the evaluation of brain lesions with 18F-FDG PET

To retrospectively assess the utility of (18)F fluorodeoxyglucose (FDG) positron emission tomography (PET) images of standardized uptake values corrected for blood glucose (SUV(gluc)), and to compare this to various quantitative methods to identify the presence or absence of high grade malignancy.

A retrospective review in 42 patients, found 81 central nervous system (CNS) lesions. Fifty one were malignant and 30 were benign or post treatment changes based on pathology (n = 32) and on clinical outcome (n = 49). Dynamic FDG PET scans were processed to generate parametric images of SUV(gluc), SUV, glucose metabolic rate (GMR), and lesion to cerebellum ratios (SUV(Rc)), and contralateral white matter ratios (SUV(Rw)). The SUV(gluc) was calculated from SUV(max) * BG/[100 mg/dl], where SUV(max) is the maximum SUV and BG is the blood glucose level (mg/dL).

Using a malignant threshold for SUV(gluc) of 4.5 and GMR of 13.0 μmole/min/100 g, the accuracies were similar for the SUV(gluc) (80%) and GMR (81%) and were higher than the conventional SUV(max) (73%). The area under the receiver operating characteristic (ROC) curve for the SUV(gluc) (0.8661) was better than that for the SUV(max) (0.7955) (p < 0.02) and was similar to those of the GMR (0.8694), SUV(Rc) (0.8278), and SUV(Rw) (0.8559).

These results suggest that the SUV(gluc) may assist in the interpretation of FDG PET brain images in patients with CNS lesions. The SUV(gluc) method avoids the complexity of kinetic modeling and the definition of a reference region.