Objectives: The aims of this study were to investigate the added value of
diffusion-weighted imaging (DWI) in pancreatic neuroendocrine tumor
(pNET) evaluation and to compare magnetic resonance imaging (MRI)
to 68Ga-DOTANOC positron emission tomography/computed tomography
Methods: Morphological MRI (T2-weighted [T2-w] + contrast-enhanced
[CE] T1-w) and DWI (T2-w + DWI) and 68Ga-DOTANOC PET/CT in
25 patients/30 pNETs were retrospectively evaluated. Per-patient and
per-lesion detection rates (pDR and lDR, respectively) were calculated.
Apparent diffusion coefficient values were compared among pNET and
surrounding and normal pancreas (control group, 18 patients). Apparent
diffusion coefficient and standardized uptake value (SUV) values were
compared among different grading and staging groups.
Results: No statistically significant differences in PET/CT and MRI session
detection rates were found (morphological MRI and DW-MRI, 88%
pDR and 87% lDR; combined evaluation, 92% pDR and 90% lDR;
68Ga-DOTANOC PET/CT, 88% pDR and 80% lDR). Consensus reading
(morphological/DW-MRI + PET/CT) improved pDR and lDR (100%).
Apparent diffusion coefficient mean value was significantly lower compared
with surrounding and normal parenchyma (P < 0.01). The apparent
diffusion coefficient and SUV values of pNETs among different grading
and staging groups were not statistically different.
Conclusions: Conventional MRI, DW-MRI + T2-w sequences, and
68Ga-DOTANOC PET/CT can be alternative tools in pNET detection.
Diffusion-weighted MRI could be valuable in patients with clinical suspicion
but negative conventional imaging findings. However, the consensus
reading of the 3 techniques seems the best approach.
- neuroendocrine tumors, pancreas, magnetic resonance imaging, diffusion-weighted imaging, 68Ga-DOTANOC positron emission tomography/computed tomography