Interest of Integrated Whole-Body PET/MR Imaging in Gastroenteropancreatic Neuroendocrine Neoplasms: A Retro-Prospective Study

• Published in: Cancers 2024-06, Vol.16 (13), p.2372
• Main Authors: Abid, Camelia, Tannoury, Jenny, Uzzan, Mathieu, Reizine, Edouard, Mulé, Sébastien, Chalaye, Julia, Luciani, Alain, Itti, Emmanuel, Sobhani, Iradj
• Format: Article
• Language: English
• Subjects: Dihydroxyphenylalanine; Endoscopy; Epilepsy; Gadolinium; Gastrointestinal tract; Glucose; Histology; Hospitals; Liver cancer; Lymphoma; Magnetic resonance imaging; Metabolism; Metastases; Metastasis; Neuroendocrine tumors; Octreotide; Positron emission tomography; Sensitivity analysis; Small intestine; Survival; Survival analysis; Tumors
• ISSN: 2072-6694; 2072-6694
• DOI: 10.3390/cancers16132372

Simultaneous positron emission tomography/magnetic resonance imaging (PET-MRI) combines the high sensitivity of PET with the high specificity of MRI and is a tool for the assessment of gastroenteropancreatic neuroendocrine neoplasms (G-NENs). However, it remains poorly evaluated with no clear recommendations in current guidelines. Thus, we evaluated the prognostic impact of PET-MRI in G-NEN patients. From June 2017 to December 2021, 71 G-NEN patients underwent whole-body PET-MRI for staging and/or follow-up purposes. A whole-body emission scan with F-6-fluoro-L-dihydroxyphenylalanine ( FDOPA, = 30), F-fluoro-2-deoxy-D-glucose ( FDG, = 21), or Ga-(DOTA(0)-Phe(1)-Tyr(3))-octreotide ( Ga-DOTATOC, = 20) with the simultaneous acquisition of a T1-Dixon sequence and diffusion-weighed imaging (DWI), followed by a dedicated step of MRI sequences with a Gadolinium contrast was performed. The patients underwent PET-MRI every 6-12 months during the follow-up period until death. Over this period, 50 patients with two or more PET-MRI were evaluated. The mean age was 61 [extremes, 31-92] years. At the baseline, PET-MRI provided new information in 12 cases (17%) as compared to conventional imaging: there were more metastases in eight, an undescribed location (myocardia) in two, and an unknown primary location in two cases. G grading at the baseline influenced overall survival. During the follow-up (7-381 months, mean 194), clinical and therapy managements were influenced by PET-MRI in three (6%) patients due to new metastases findings when neither overall, nor disease-free survivals in these two subgroups ( = 12 vs. = 59), were different. Our study suggests that using PET/MRI with the appropriate radiotracer improves the diagnostic performance with no benefit on survival. Further studies are warranted to evaluate the cost-effectiveness of this procedure.