Imaging is critical for diagnosis, staging and therapeutic decision for patients with neuroendocrine neoplasms (NENs). An integration of conventional (computed tomography -CT- and magnetic resonance imaging ¿MRI-) and functional (positron emission tomography -PET-) techniques has significantly improved the diagnosis and follow-up of these neoplasms, becoming standard practice before and after treatment. In this scenario, MRI with diffusion-weighted imaging (DWI), has expanded the diagnostic potentiality of conventional imaging. The objectives of the study are a) to compare the diagnostic performance of DWI-MRI with PET-CT with 68Ga-peptides in NEN liver metastases (LM); b) to compare the apparent diffusion coefficient (ADC) obtained with DWI-MRI and the standardized absorption value (SUV) obtained with 68Ga-peptides PET-CT in NEN LM; c) to determine the prognostic role of DWI-MRI in relation to the grading, staging, and clinical follow-up. A retrospective analysis will be conducted including all consecutive patients with confirmed diagnosis of NEN, followed by the multidisciplinary group dedicated to the management of NENs of the Policlinico Umberto I (NETTARE unit), from January 2016 to October 2021. Patients evaluated both with MRI (conventional sequences and DWI) and with PET-CT with 68Ga-peptides will be included in the study. From this study we could expect that the diagnostic performance of MRI with DWI sequences could be comparable or sometimes superior with that of PET-CT with 68Ga-peptides in NEN LM. MRI with DWI could be complementary to PET-CT with 68Ga-peptides and in some patients could provide more accurate information about the extension of the disease and the biological aggressiveness. This information could be useful for choosing the best therapeutic strategy and the best clinical and instrumental follow-up for these patients.
This research moves from the experience of the Neuroendocrine Tumor task force (NETTARE) of the "Sapienza" University - Policlinico Umberto I, a multidisciplinary tumor board aimed at sharing clinical cases, diagnostic strategies, therapeutic management and oriented research projects. We have recently published some case reports and systematic reviews on several interesting topics in this field. Considering, the recent investigations of DWI-MRI as a possible modality to stage patients with NENs, we designed this study with the aim to investigate the benefit of DWI in the diagnosis and follow-up of LM from NENs in comparison with functional imaging.
From this study we could expect that the diagnostic accuracy of MRI with DWI sequences could be comparable or sometimes superior with that of PET-CT with 68Ga-peptides in LM from NENs. MRI with DWI could be complementary to PET-CT with 68Ga-peptides and in some patients could provide more accurate information about the extension of the disease and the biological aggressiveness. This information could be useful for choosing the best therapeutic strategy and the best clinical and instrumental follow-up for these patients.