Prognostic value of a three-scale grading system based on combining molecular imaging with 68Ga-DOTATATE and 18F-FDG PET/CT in patients with metastatic gastroenteropancreatic neuroendocrine neoplasias
Ioannis Karfis, Gwennaëlle Marin, Hugo Levillain, Stylianos Drisis, Raoul Muteganya, Gabriela Critchi, Loubna Taraji-Schiltz, Carlos Artigas Guix, Leila Shaza, Meriem Elbachiri, Laura Mans, G. Machiels, Alain Hendlisz, Patrick Flamen
Abstract
// Ioannis Karfis 1 , Gwennaëlle Marin 1 , Hugo Levillain 1 , Stylianos Drisis 2 , Raoul Muteganya 1 , Gabriela Critchi 1 , Loubna Taraji-Schiltz 1 , Carlos Artigas Guix 1 , Leila Shaza 3 , Meriem Elbachiri 3 , Laura Mans 3 , Godelieve Machiels 3 , Alain Hendlisz 3 and Patrick Flamen 1 1 Nuclear Medicine Department, Institut Jules Bordet-Université Libre de Bruxelles (ULB), Brussels, Belgium 2 Radiology/Medical Imaging Department, Institut Jules Bordet-Université Libre de Bruxelles (ULB), Brussels, Belgium 3 Digestive Oncology Department, Institut Jules Bordet-Université Libre de Bruxelles (ULB), Brussels, Belgium Correspondence to: Ioannis Karfis, email: [email protected] Keywords: gastroenteropancreatic neuroendocrine neoplasias; molecular imaging; prognostic biomarkers; 68 Ga-DOTATATE PET/CT; 18 F-FDG PET/CT Received: October 02, 2019     Accepted: January 13, 2020     Published: February 11, 2020 ABSTRACT We investigated on the added prognostic value of a three-scale combined molecular imaging with 68 Ga-DOTATATE and 18 F-FDG PET/CT, (compared to Ki-67 based histological grading), in gastroenteropancreatic neuroendocrine neoplasia patients. 85 patients with histologically proven metastatic gastroenteropancreatic neuroendocrine neoplasias, who underwent combined PET/CT imaging were retrospectively evaluated. Highest Ki-67 value available at time of 18 F-FDG PET/CT was recorded. Patients were classified according to World Health Organization/European Neuroendocrine Tumor Society histological grades (G1, G2, G3) and into three distinct imaging categories (C1: all lesions are 18 F-FDG negative/ 68 Ga-DOTATATE positive, C2: patients with one or more 18 F-FDG positive lesions, all of them 68 Ga-DOTATATE positive, C3: patients with one or more 18 F-FDG positive lesions, at least one of them 68 Ga-DOTATATE negative). The primary endpoint of the study was Progression-Free Survival, assessed from the date of 18 F-FDG PET/CT to the date of radiological progression according to Response Evaluation Criteria In Solid Tumors version 1.1. Classification according to histological grade did not show significant statistical difference in median Progression-Free Survival between G1 and G2 but was significant between G2 and G3 patients. In contrast, median Progression-Free Survival was significantly higher in C1 compared to C2 and in C2 compared to C3 patients, revealing three distinctive imaging categories, each with highly distinctive prognosis. Our three-scale combined 68 Ga-DOTATATE/ 18 F-FDG PET imaging classification holds high prognostic value in patients with metastatic gastroenteropancreatic neuroendocrine neoplasias.