Nomogram to Predict Progression-free Survival in Patients with Well-differentiated, Stage IV Gastroenteropancreatic Neuroendocrine Tumors Treated with Somatostatin Analogues: Data of TRASGU-GETNE Study - Jimenez-Fonseca, P; Alonso, V; Riesco, M C; Custodio, A; Molina-Cerrillo, J; Sanchez Canovas, M; Benavent, M; Hernando Cubero, J; La Casta, A; Lopez, C; Marazuela Azpiroz, M; Carmona-Bayonas, A (Neuroendocrinology, 2019)