PET/CT with 18F-Fluorodeoxyglucose Diagnosis of Multiple Myeloma
Abstract
Background . Modern hybrid PET/CT technology with 2-[ 18 F]fluoro-2-deoxy-B-glucose ( 18 F-FDG) is widely used in multiple myeloma (MM) patients. However, a number of issues in the evaluation of PET/CT results require further analysis and systematization. Aim: To investigate the role of FDG PET/CT in the diagnostics of MM. Materials and Methods. The analysis included the results of 40 18 F-FDG PET/CT examinations performed in 40 patients with MM before therapy. To systematize the description of PET/CT findings, based on the analysis of fused images (including abnormalities on CT, PET or both) three types of lesions were identified: focal, diffuse, and diffuse-focal. The analysis included visual and semiquantitative assessment. Results. In analyzed group (n = 40) 18F-FDG PET/CT showed focal lesions in 72% (n = 29) of cases, diffuse lesions — in 13% (n = 5), and diffuse-focal lesions in 15% (n = 6). In 33% (13/40) cases PET/CT results were 18 F-FDG-negative – all focal lesions. In the subgroup with focal and diffuse-focal type (n = 40), bone marrow lesions, according to 18 F-FDG increased uptake without corresponding structural abnormalities on CT, were detected in 5% (2/40). In the subgroup with osteolytic foci and plasmacytomas structural lesions showed significant differences in 18 F-FDG uptake intensity – SUL max values ranged from 1.6 to 22.2. This was observed both in the subgroups with focal and diffuse-focal type as a whole, as well as in individual patients, including lesions of comparable size. Conclusion . The obtained results demonstrate significant polymorphism of changes detected by 18 F-FDG PET/CT in MM patients at the diagnostic stage. Analysis of three PET/CT types of images – PET, CT, and fused – allowed for the identification of the main types of lesions: focal, diffuse, and diffuse-focal. The use of the proposed classification will allow for the standardization of PET/CT result descriptions and increase the accuracy of their assessment during follow-up studies in the course of MM patient treatment.