Whole-Body Diffusion-Weighted MRI VERSUS 18F-FDGPET/CT in Assessment of Lymphoma

Gomaa, Manal Ibrahim; Zidan, Hagar Said; Korayem, Enas; Tawfeek, Eman Abdelrazek; Abokoura, Sameh

doi:10.21608/ijma.2025.375443.2165

Whole-Body Diffusion-Weighted MRI VERSUS 18F-FDGPET/CT in Assessment of Lymphoma

Document Type : Original Article

Authors

¹ Department of Diagnostic and Interventional Radiology, National Liver Institute, Menoufia University, Shebin El-Kom, Egypt.

² Department of Oncology, Faculty of Medicine, Menoufia University, Shebin El-Kom, Egypt.

10.21608/ijma.2025.375443.2165

Abstract

Background: Lymphomas comprise 5-6% of all cancers. While positron emission tomography [PET] scans, using the [¹⁸F]- Fluorodeoxyglucose tracer [¹⁸F-FDG PET/CT] remain standard for staging/follow-up, radiation concerns have increased interest in whole-body diffusion-weighted MRI [WB-DW MRI], which provides both anatomical and functional data through apparent diffusion coefficient values. This study aimed to compare the diagnostic accuracy of DW WB-MRI with that of ¹⁸F-FDG PET/CT for assessment of malignant activity in lymphoma patients during follow-up period.
Patients and methods: This prospective study included 35 pathologically proven lymphoma patients at National Liver Institute [June 2024-February 2025]. All underwent both ¹⁸F-FDG PET/CT and WB-DW MRI imaging modalities approximately 2.5 days apart. Nine lymph node groups and extra-nodal organs were evaluated per patient, with PET/CT as the gold standard.
Results: WB-DW MRI showed high performance for nodal disease [sensitivity 94.44%, specificity 94.12%, accuracy 94.29%] and excellent sensitivity [100%] for extra-nodal assessment with good accuracy [91.43%]. A significant negative correlation existed between apparent diffusion coefficient [ADC] values and Maximum standardized uptake value [SUVmax] [p=0.001]. A staging agreement occurred in 65% of patients. In discordant cases, WB-DW MRI upstaged 27.3% of stage II patients and downstaged 75% of stage III patients [p<0.001].
Conclusion: Health literacy significantly influences medication adherence among elderly patients with WB-DW MRI offers a radiation-free alternative to 18F-FDG PET/CT for lymphoma restaging, with comparable accuracy in nodal assessment and superior sensitivity for diffuse BM involvement. However, its limitations in spleen evaluation and lack of standardized protocols temper its routine adoption.

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