Multitracer PET/CT with [(18)F]Fluorodeoxiglucose and [(18)F]Fluorocholine in the Initial Staging of Multiple Myeloma Patients Applying the IMPeTus Criteria: A Pilot Study

Initial staging of patients diagnosed with multiple myeloma (MM) can lead to negative results using conventional diagnostic imaging workup, including [(18)F]Fluorodesoxiglucose ([(18)F]FDG) PET/CT. The aim of this prospective pilot study was to evaluate the diagnostic efficacy of [(18)F]Fluorocholine ([(18)F]FCH) PET/CT in the initial staging of MM patients who were candidates for autologous bone marrow transplant. Materials and Methods: The inclusion criteria of our study were: (a) patients diagnosed with MM; (b) candidates for autologous bone marrow transplant (AT); and (c) studied with [(18)F]FCH PET/CT and [(18)F]FDG PET/CT for initial staging less than 4 weeks apart. Imaging analysis included the presence of: bone marrow infiltration, focal bone lesions, and para-medullary or extra-medullary disease, according to the proposed IMPeTus criteria. The analysis was performed per lesion, per patient, and per location. Results: The study population included ten patients. Globally, [(18)F]FCH PET/CT showed bone marrow uptake in all the patients and visualised 16 more focal lesions than [(18)F]FDG PET/CT. One patient presented a plasmacytoma, detected by both tracers. Extra-medullary and para-medullary disease was identified with different degrees of uptake by both tracers. In summary, [(18)F]FCH PET seemed to be superior to [(18)F]FDG PET/CT in detecting focal bone lesions. SUVmax values were slightly higher in [(18)F]FCH PET/CT than in [(18)F]FDG PET/CT. Conclusions: Taking into account the small study population, according to our results, [(18)F]FCH PET/CT could be a useful tool for staging MM patients.