Marius Erik Mayerhoefer MD, PhD, Abstract Co-Author: Nothing to Disclose

Thomas Knogler MD, Presenter: Nothing to Disclose

Helmut Prosch MD, Abstract Co-Author: Nothing to Disclose

Georgios Karanikas MD, Abstract Co-Author: Nothing to Disclose

Kurt Kletter MD, Abstract Co-Author: Nothing to Disclose

Katja Pinker-Domenig MD, Abstract Co-Author: Nothing to Disclose

Dominik Berzaczy MD, Abstract Co-Author: Nothing to Disclose

Michael Weber, Abstract Co-Author: Nothing to Disclose

Ulrich Jaeger MD, Abstract Co-Author: Nothing to Disclose

Barbara Kiesewetter MD, Abstract Co-Author: Nothing to Disclose

Philipp Ubl MD, Abstract Co-Author: Nothing to Disclose

Markus Raderer MD, Abstract Co-Author: Nothing to Disclose

To determine the value of diffusion-weighted MR imaging (DWI) for pre-therapeutic assessment and staging of patients with (1) fluorodeoxyglucose (FDG)-avid lymphoma (e.g., diffuse large B-cell lymphoma [DLBCL]), and (2) lymphoma with variable FDG-avidity (e.g., extranodal marginal zone B-cell lymphoma of the mucosa-associated lymphoid tissue [MALT]).

Treatment-naïve lymphoma patients that were referred for pre-therapeutic whole-body staging were included in this prospective study. Group A included patients with FDG-avid lymphoma (e.g., Hodgkin, DLBCL, and follicular lymphoma), whereas Group B included patients with lymphoma of variable FDG-avidity (e.g., MALT lymphoma, small lymphocytic lymphoma). All patients underwent DWI-MRI and 18F-FDG-PET/CT (positron emission tomography/computed tomography) with a venous-phase contrast-enhanced (CE-)CT series. Region-based sensitivity and agreement with Ann Arbor staging, relative to the reference standard, were calculated for DWI-MRI, and, in Group B, also 18F-FDG-PET/CT and CE-CT.

In Group A (100 patients), DWI-MRI had a region-based sensitivity of 97%, and with regard to staging, agreed with the reference standard in 94/100 patients (kappa, 0.92). In Group B (40 patients; 38 MALT), DWI-MRI, 18F-FDG-PET/CT, and CE-CT had region-based sensitivities of 94.4%, 60.9%, and 70.7%, respectively. With regard to staging in Group B, DWI-MRI, 18F-FDG-PET/CT, and CE-CT agreed with the reference standard in 37/40, 26/40, and 24/40 patients, with kappa values of 0.89, 0.52, and 0.43, respectively.

In patients with FDG-avid lymphoma, DWI-MRI appears to be only slightly inferior to 18F-FDG-PET/CT, with regard to pre-therapeutic regional assessment and staging. In patients with lymphoma subtypes that show a variable FDG-avidity, particularly MALT lymphoma, DWI-MRI appears to be superior to both 18F-FDG-PET/CT and CE-CT.

DWI-MRI may be a general alternative to 18F-FDG-PET/CT for pre-therapeutic lymphoma staging. In MALT lymphoma, DWI-MRI even appears to be superior not only to 18F-FDG-PET/CT, but also to CE-CT, which is the currently recommended imaging test in this type of lymphoma. This is particularly relevant for younger lymphoma patients, because, contrary to 18F-FDG-PET/CT or CE-CT, DWI-MRI is not associated with potentially harmful radiation, and may thus be better-suited for life-long follow-up.

Mayerhoefer, M, Knogler, T, Prosch, H, Karanikas, G, Kletter, K, Pinker-Domenig, K, Berzaczy, D, Weber, M, Jaeger, U, Kiesewetter, B, Ubl, P, Raderer, M, Diffusion-weighted Magnetic Resonance Imaging for Pre-therapeutic Assessment and Staging of Lymphoma: A Prospective Study in 140 Patients.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14001331.html