Whole-body diffusion-weighted MRI and (18)F-FDG PET/CT can discriminate between different lymphoma subtypes

Area of Science:

• Oncology
• Radiology
• Medical Imaging

Background:

• Lymphoma characterization and prognosis are critical for treatment decisions.
• Combined imaging techniques like PET/CT and DWI offer potential for improved diagnostic accuracy.

Purpose of the Study:

• To evaluate the combined use of 2-[(18)F]-fluoro-2-deoxy-d-glucose (FDG) PET/CT and diffusion-weighted imaging (DWI) for differentiating lymphoma subtypes.
• To assess the prognostic value of quantitative parameters from whole-body DWI and FDG PET/CT in lymphoma patients.

Main Methods:

• Whole-body MRI with DWI and FDG PET/CT were performed pre-treatment in 50 lymphoma patients.
• Quantitative parameters from DWI (mean apparent diffusion coefficient - ADC) and FDG PET/CT (SUVmax, SUVmean) were analyzed.
• Correlation with overall survival (OS) and progression-free survival (PFS) was assessed.

Main Results:

• Indolent non-Hodgkin's lymphoma (NHL) exhibited significantly lower mean ADC values compared to Hodgkin's lymphoma (HL) and aggressive NHL (p=0.013).
• Aggressive NHL showed higher SUVmax than HL.
• Increased mean ADC correlated with longer OS (p=0.006). A combined model of SUVmean and mean ADC showed potential for predicting PFS.

Conclusions:

• Mean ADC effectively discriminates between indolent and aggressive NHL, aiding in the assessment of lymphoma transformation.
• Quantitative parameters from ADC and FDG PET/CT, individually or combined, do not independently predict OS or PFS across all lymphoma subtypes.