RT Journal Article SR Electronic T1 11C-Acetate PET/CT for Metabolic Characterization of Multiple Myeloma: A Comparative Study with 18F-FDG PET/CT JF Journal of Nuclear Medicine JO J Nucl Med FD Society of Nuclear Medicine SP 749 OP 752 DO 10.2967/jnumed.113.131169 VO 55 IS 5 A1 Chi-lai Ho A1 Sirong Chen A1 Yim Lung Leung A1 Thomas Cheng A1 Ka-nin Wong A1 Shing Kee Cheung A1 Raymond Liang A1 Chor Sang Chim YR 2014 UL http://jnm.snmjournals.org/content/55/5/749.abstract AB We prospectively compared 11C-acetate with 18F-FDG in a PET/CT evaluation of multiple myeloma (MM), specifically on diagnostic accuracy, identification of high-risk patients, and monitoring of treatment response. Methods: Dual-tracer PET/CT was performed on 35 pathologically and clinically confirmed and untreated patients (26 with symptomatic MM, 5 with smoldering MM, and 4 with monoclonal gammopathy of unknown significance) and 20 individuals with normal marrow. Results: 11C-acetate showed significant incremental value over 18F-FDG (84.6% vs. 57.7%) for positively identifying patients with diffuse and focal symptomatic MM, and was negative in patients with indolent smoldering MM and monoclonal gammopathy of unknown significance. Three functional parameters—number of 11C-acetate–avid and 18F-FDG–avid focal bone lesions and 11C-acetate general marrow activity—strongly correlated with β-2-microglobulin as surrogate imaging markers of tumor burden. After induction chemotherapy, the metabolic change in 11C-acetate general marrow activity correlated with clinical response. Conclusion: Metabolic characterization of MM in diagnosis, risk stratification, and treatment monitoring can be done more accurately by assessing lipid metabolism with 11C-acetate than by assessing glucose metabolism with 18F-FDG.