Evaluation of Diffusion-weighted Magnetic Resonance Imaging for Follow-Up and Treatment Response Assessment of Lymphoma: Results of an 18F-FDG-PET/CT-controlled Prospective Study in 64 Patients
Menée sur 64 patients atteints d'un lymphome hodgkinien ou non hodgkinien diagnostiqué à l'aide d'une tomographie numérique par émission de positrons à base de fluorodésoxyglucose (18F-FDG-PET/CT), cette étude évalue, par rapport à une 18F-FDG-PET/CT, l'intérêt d'une IRM pondérée en diffusion pour évaluer la réponse au traitement et suivre l'évolution de la maladie
PURPOSE : To determine the value of diffusion-weighted magnetic resonance imaging (DWI-MRI) for treatment response assessment in fluorodesoxy-glucose (FDG)-avid lymphoma.
EXPERIMENTAL DESIGN : Patients with FDG-avid Hodgkin (HL) or Non-Hodgkin lymphoma (NHL) at pre-therapeutic 18F-FDG-PET/CT, who had also undergone pre-therapeutic whole-body DWI-MRI, were included in this prospective study. Depending on the histological lymphoma subtype, patients received different systemic treatment regimens, and follow-up DWI-MRI and 18F-FDG-PET/CT were performed at one or more time points, depending on the clinical course. For each follow-up DWI-MRI, region-based rates of agreement, and rates of agreement in terms of treatment response (complete remission, partial remission, stable disease, or progressive disease), relative to the corresponding 18F-FDG-PET/CT, were calculated.
RESULTS : 64 patients were included: 10 with HL, 22 with aggressive NHL, and 32 with indolent NHL. The overall region-based agreement of DWI-MRI with 18F-FDG-PET/CT was 99.4%. For the 51 interim examinations (performed after 1-3 therapy cycles) region-based agreement of DWI-MRI with 18F-FDG-PET/CT was 99.2%, and for the 48 end-of-treatment examinations, agreement was 99.8%. No significant differences, in terms of region-based agreement between DWI-MRI and 18F-FDG-PET/CT, were observed between the three lymphoma groups (HL, aggressive NHL, indolent NHL) (P=.25), or between interim and end-of-treatment examinations (P=.21). With regard to treatment response assessment, DWI-MRI agreed with 18F-FDG-PET/CT in 99/102 follow-up examinations (97.1%), with a kappa value of 0.94 (P<.0001).
CONCLUSIONS : In patients with FDG-avid lymphoma, DWI-MRI may be a feasible alternative to 18F-FDG-PET/CT for follow-up and treatment response assessment.
Clinical Cancer Research , résumé, 2015