Choline PET/CT in Multiple Myeloma

The field of multiple myeloma (MM) imaging has evolved. The International Myeloma Working Group recently recommended performing ¹⁸F-fluorodeoxyglucose glucose (¹⁸FDG) positron emission tomography/computed tomography (PET/CT) with the aim of staging MM patients at baseline and evaluating response to therapy. Novel oncological radiotracers such as ¹¹C-Choline and ¹⁸F-Fluorocholine, have been studied in comparison with ¹⁸FDG, mostly in MM patients presenting with refractory disease or suspected relapse. Choline-based tracers may overcome some limitations of ¹⁸FDG, which include a lack of sensitivity in depicting skull lesions and the fact that 10% of MM patients are FDG-negative. The majority of MM lesions display a higher uptake of Choline than FDG. Also, in many situations, Choline may offer better lesion visualization, with a higher tumor to background ratio; however, various patterns of Choline and FDG uptake have been observed in MM and some limitations, notably as regards liver lesions, should be recognized. Overall, Choline may provide additional detection of up to 75% more lesions. This article aims to provide a comprehensive review of the potential role of Choline in multiple myeloma, as compared to FDG, encompassing Choline physiopathology as well as data from clinical studies.