CXCR4 and plasma cell myeloma: More recently, 11C-Methionine PET/CT and chemokine (C-X-C motif) receptor 4 (CXCR4) directed 68Ga-Pentixafor PET/CT have also been evaluated in symptomatic multiple myeloma (MM), and showed promising results for detection of intra- and extramedullary MM lesions when compared with standard 18F-FDG PET/CT [9,10,11,12].