Marius Erik Mayerhoefer MD, PhD, Presenter: Nothing to Disclose

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

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

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

Michael Weber, Abstract Co-Author: Nothing to Disclose

Thomas Knogler MD, Abstract Co-Author: Nothing to Disclose

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

To determine the value of diffusion-weighted magnetic resonance imaging (DWI-MRI) for treatment response assessment in fluorodesoxy-glucose (FDG)-avid lymphoma.

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 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 sensitivity/specificity and 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.

64 patients were included: 10 with HL, 22 with aggressive NHL, and 32 with indolent NHL. Overall region-based DWI-MRI sensitivity and specificity were 97.6% (95% confidence interval (CI), 91.7-99.3%), and specificity was 99.5% (95% CI, 99.0-99.9%). For the 51 interim DWI/MRI examinations (performed after 1-3 therapy cycles) region-based sensitivity and specificity were 95.1% (95% CI, 83.9-98.7%) and 99.4% (95% CI, 98.9-99.9%), and for 48 end-of-treatment DWI/MRI examinations examinations, sensitivity and specificity were 100% (95% CI, 89.6-100%) and 99.8% (95% CI, 99.4-100%). With regard to treatment response assessment, DWI-MRI agreed with 18F-FDG-PET/CT in in 99/102 follow-up examinations (97.1%), with a kappa value of 0.94 (P<.0001).

In patients with FDG-avid lymphoma, DWI-MRI is a feasible alternative to 18F-FDG-PET/CT for follow-up and treatment response assessment, regardless of the histological subtype (i.e., Hodgkin lymphoma, agressive NHL, indolent NHL).

DWI-MRI may be used as an alternative to 18F-FDG-PET/CT for follow-up and monitoring of lymphoma, due to its lower cost, general availability, and lack of ionizing radiation exposure. The latter is of particular relevance for younger lymphoma patients that may require life-long follow-up, to lower the risk of radiation-induced secondary cancers.

Mayerhoefer, M, Karanikas, G, Prosch, H, Kiesewetter, B, Weber, M, Knogler, T, Raderer, M, 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.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14015328.html