Objective: To assess the diagnostic performance of [F18] fluoro-2-desoxy-D-glucose positron emission tomography/CT [(18F) FDG-PET/CT] compared to diffusion-weighted imaging (DWI)-MRI of lesion detection in patients with non-FDG avid gastric mucosa-associated lymphoid tissue (MALT) lymphoma.
Methods: 19 patients with histologically proven gastric MALT lymphoma were included in this prospective Institutional Review Board-approved study. Patients underwent [18F]-FDG-PET/CT and consecutive MRI/DWI. Images were evaluated for the presence of gastric lesions in two anatomically defined groups (region 1: cardia, body, fundus; region 2: antrum, pyloric region) by two senior board-certified radiologists, in an observer-blinded manner. Overall accuracy relative to the reference standard (histology obtained by biopsy) was calculated for each reader and a consensus rating.
Results: We found a statistically significant higher accuracy of lesion detection for lesions in region 1 (p = 0.030) and 2 (p = 0.070) for DWI-MRI (100%/78.9%) than for CT (68.4%/42.1%).
Conclusion: DWI-MRI seems to be superior accurate to CT for lesion detection in non-FDG avid gastric MALT lymphoma.
Advances in knowledge: DWI-MRI seems to be an alternative reliable imaging method for locoregional disease evaluation of non-FDG avid gastric MALT lymphoma.