Comparison of [68Ga]-FAPI PET/CT and [18F]-FDG PET/CT in Multiple Myeloma: Clinical Experience

Umut Elboga; Ertan Sahin; Yusuf Burak Cayirli; Merve Okuyan; Gokmen Aktas; Handan Haydaroglu Sahin; Ilkay Dogan; Tulay Kus; Dervis Murat Akkurd; Ufuk Cimen; Vuslat Mumcu; Benan Kilbas; Yusuf Zeki Celen

doi:10.3390/tomography8010024

Comparison of [68Ga]-FAPI PET/CT and [18F]-FDG PET/CT in Multiple Myeloma: Clinical Experience

Tomography. 2022 Feb 1;8(1):293-302. doi: 10.3390/tomography8010024.

Authors

Affiliations

¹ Department of Nuclear Medicine, Gaziantep University, Gaziantep 27310, Turkey.
² Department of Oncology, Medical Park Private Hospital, Gaziantep 27090, Turkey.
³ Department of Hematology, Gaziantep University, Gaziantep 27310, Turkey.
⁴ Department of Biostatistics, Gaziantep University, Gaziantep 27310, Turkey.
⁵ Department of Oncology, Gaziantep University, Gaziantep 27310, Turkey.
⁶ Department of R&D, Moltek Health Services Production & Marketing Inc., Kocaeli 41400, Turkey.

Abstract

Objective: In this study, we aimed to compare [68Ga]FAPI PET/CT and [18F]FDG PET/CT imaging to detect lesions in multiple myeloma.

Methods: A total of 14 patients with multiple myeloma who underwent [68Ga]FAPI PET/CT and [18F]FDG PET/CT imaging were included in this retrospective study. SUV_max values of [68Ga]FAPI and [18F]FDG were compared according to lesion locations. Also, lesion localization ability of both imaging methods was compared on the patient basis.

Results: In 4 of 14 patients, [68Ga]FAPI PET/CT and [18F]FDG PET/CT have not detected any bone lesions. In 8 of the remaining 10 patients [18F]FDG PET/CT detected bone lesions but in this group, 6 patients showed more higher SUV_max values than [18F]FDG PET/CT in [68Ga]FAPI PET/CT.In contrast, 2 of 8 patients showed more higher SUV_max values than [68Ga]FAPI PET/CT in [18F]FDG PET/CT. Moreover, [68Ga]FAPI PET/CT detected bone lesions in two patients, which werenot detected by [18F]FDG PET/CT. Also, in five patients, [68Ga]FAPI PET/CT showed more bone lesions in comparison with[18F]FDG PET/CT. Only one patient, [18F]FDG PET/CT showed more bone lesions. Three extramedullary involvements were observed in the following locations: lung, presacral lymph node, and soft tissue mass lateral to the right maxillary sinus. Among these involvements, higher SUV_max values were observed in the lung and presacral lymph node with [68Ga]FAPI compared to [18F]FDG. However, the soft tissue mass showed a higher SUV_max value in [18F]FDG than [68Ga]FAPI.

Conclusions: No significant superiority was observed in [68Ga]FAPI PET/CT over [18F]FDG PET/CT in patients with MM. However, [68Ga]FAPI PET/CT can be utilized as a complementary imaging method to [18F]FDG PET/CT in some settings, especially in low-[18F]FDG affinity and inconclusive cases. Considering the favorable aspects of [68Ga]FAPI PET/CT in MM, such as low background activity, absence of non-specific bone marrow, and physiological brain involvement, further studies with a larger sample size should be conducted.

Keywords: [18F]FDG; [68Ga]FAPI; multiple myeloma.

MeSH terms

Bone Diseases*
Fluorodeoxyglucose F18
Humans
Multiple Myeloma* / diagnostic imaging
Positron Emission Tomography Computed Tomography / methods
Retrospective Studies

Substances

Fluorodeoxyglucose F18