Agni Tsangaridi, Afroditi Gakidi, Ioannis Iakovou, Antonia Dimitrakopoulou-Strauss, Christos Sachpekidis
18F-FDG PET/CT plays an important role in multiple myeloma (MM) by providing functional information that complements anatomical assessment. Its clinical applications extend from disease detection and baseline prognostic evaluation to treatment response and minimal residual disease (MRD) assessment. 18F-FDG PET/CT findings such as focal lesion burden, intensity of 18F-FDG uptake, paramedullary (PMD) and extramedullary disease (EMD) have been associated with adverse outcomes, while metabolic response during or following treatment provides robust prognostic information. 18F-FDG PET/CT also complements bone marrow-based MRD assessment by detecting residual disease outside the biopsy site. However, false-positive and false-negative findings, together with incomplete standardisation of quantitative parameters, can complicate interpretation. Novel PET radiotracers and artificial intelligence (AI)-based quantitative approaches are currently under investigation. This review summarises the current role of 18F-FDG PET/CT in MM, with emphasis on initial diagnosis and disease extent evaluation, prognostic value, treatment response and MRD assessment, limitations and future perspectives.