RT Journal Article SR Electronic T1 Glucose-Normalized Standardized Uptake Value from 18F-FDG PET in Classifying Lymphomas JF Journal of Nuclear Medicine JO J Nucl Med FD Society of Nuclear Medicine SP 1659 OP 1663 VO 46 IS 10 A1 Wong, Ching-yee Oliver A1 Thie, Joseph A1 Parling-Lynch, Kelly J. A1 Zakalik, Dana A1 Margolis, Jeffrey H. A1 Gaskill, Marianne A1 Hill, Jack A1 Qing, Feng A1 Fink-Bennett, Darlene A1 Nagle, Conrad YR 2005 UL http://jnm.snmjournals.org/content/46/10/1659.abstract AB Our objective was to derive the best glucose sensitivity factor (g-value) and the most discriminating standardized uptake value (SUV) normalized to glucose for classifying indolent and aggressive lymphomas. Methods: The maximum SUV obtained from 18F-FDG PET over the area of biopsy in 102 patients was normalized by serum glucose ([Glc]) to a standard of 100 mg/dL. Discriminant analysis was performed by using each SUV100 (SUV × {100/[Glc]}g, calculated using various g-values ranging from −3.0 to 0, one at a time) as a variable against the lymphoma grades, and plotting the percentage of correct classifications against g (g-plot) to search for the best g-value in normalizing SUV100 for classifying grades. To address the influence of the extreme glucose conditions, we repeated the same analyses in 12 patients with [Glc] ≤ 70 mg/dL or [Glc] ≥ 110 mg/dL. Results: SUV100 correctly classified lymphoma grades ranging from 62% to 73% (P < 0.0005), depending on the g-value, with a maximum at a g-value of −0.5. For the subgroup with extreme glucose values, the g-plot also revealed higher and more optimal discrimination at a g-value of −0.5 (92%) than at a g-value of 0 (83%) (P = 0.03). The discrimination deteriorated at g < −1 in both analyses. The box plot for all cases using a g-value of −0.5 showed little overlap in classifying lymphoma grades. For a visually selected threshold SUV100 of 7.25, the sensitivity, specificity, and accuracy of identifying aggressive grades were 82%, 79%, and 81%, respectively. Conclusion: The results suggest that metabolic discrimination between lymphoma grades using a glucose-normalized SUV from 18F-FDG PET is improved by introducing g-value as an extra degree of freedom.