title: Application of (18)F-FDG PET and diffusion weighted imaging (DWI) in multiple myeloma: comparison of functional imaging modalities.
abstract: Aim of this prospective study was to assess the sensitivity of positron emission tomography (PET) and diffusion-weighted imaging (DWI) in detecting multiple myeloma (MM) lesions, using the well-established morphologic modalities magnetic resonance imaging (MRI) and computed tomography (CT) as the standard of reference (RS). The study included 24 MM patients (15 newly diagnosed, 9 pre-treated). All underwent (18)F-FDG PET/CT and wholebody DWI. The findings in PET and DWI were compared to matching imaging findings in combined non-enhanced T1w, fat-saturated T2w (TIRM)- MRI, and low-dose CT. Patient-based analysis revealed that 15/24 patients (10 primary MM, 5 pre-treated) had myeloma lesions according to our RS. PET was positive in 13/24 patients (11 primary MM, 2 pre-treated) and DWI in 18/24 patients (12 primary MM, 6 pre-treated). Lesion-based analysis demonstrated 128 MM lesions, of which PET depicted 60/128 lesions (sensitivity 47%), while DWI depicted 99/128 lesions (sensitivity 77%). Further analysis including only the 15 untreated MM patients revealed a sensitivity of 90% for both PET and DWI and an overall concordance of PET and DWI of 72%. In conclusion, DWI was more sensitive than (18)F-FDG PET in detecting myeloma lesions in a mixed population of primary and pre-treated MM patients. However, (18)F-FDG PET and DWI demonstrated equivalent sensitivities in the sub-population of primary, untreated MM patients. This higher sensitivity of DWI in pre-treated patients may be due to the fact that (18)F-FDG PET becomes negative earlier in the course of treatment in contrary to MRI, in which already treated lesions can remain visible.
authors.affiliation: Clinical Cooperation Unit Nuclear Medicine, German Cancer Research Center (DKFZ) Heidelberg, Germany.
authors.forename: Christos
authors.initials: C
authors.lastname: Sachpekidis
authors.affiliation: Department of Radiology, German Cancer Research Center (DKFZ) Heidelberg, Germany.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Mosebach
authors.affiliation: Department of Radiology, German Cancer Research Center (DKFZ) Heidelberg, Germany.
authors.forename: Martin T
authors.initials: MT
authors.lastname: Freitag
authors.affiliation: Department of Radiology, German Cancer Research Center (DKFZ) Heidelberg, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Wilhelm
authors.affiliation: Department of Medicine V, University Clinic Heidelberg Heidelberg, Germany.
authors.forename: Elias K
authors.initials: EK
authors.lastname: Mai
authors.affiliation: Department of Medicine V, University Clinic Heidelberg Heidelberg, Germany.
authors.forename: Hartmut
authors.initials: H
authors.lastname: Goldschmidt
authors.affiliation: Division of Nuclear Medicine, University Clinic Heidelberg Heidelberg, Germany.
authors.forename: Uwe
authors.initials: U
authors.lastname: Haberkorn
authors.affiliation: Department of Radiology, German Cancer Research Center (DKFZ) Heidelberg, Germany.
authors.forename: Heinz-Peter
authors.initials: HP
authors.lastname: Schlemmer
authors.affiliation: Department of Radiology, German Cancer Research Center (DKFZ) Heidelberg, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Delorme
authors.affiliation: Clinical Cooperation Unit Nuclear Medicine, German Cancer Research Center (DKFZ) Heidelberg, Germany.
authors.forename: Antonia
authors.initials: A
authors.lastname: Dimitrakopoulou-Strauss
keywords: 18F-FDG PET; DWI; Multiple myeloma