Grade1-2 Advanced Midgut Neuroendocrine Tumors (NETs)

This is a randomized Phase II/late phase I de-escalation clinical trial with approved investigational medicinal products in new use condition, low intervention. Disease under study Patients with unresectable or metastatic, slowly progressive, well-differentiated (Grade1 and Grade2), somatostatin receptor-positive midgut neuroendocrine tumors (GEP-NETs). It is planned to randomize 166 patients with a histologically confirmed diagnosis of slowly progressive grade 1 or grade 2 advanced midgut neuroendocrine tumors (NETs) candidates to receive 177Lu-Dotatate targeted radioligand therapy (RLT). Patients are required to have SSTR+ disease, as evidenced on somatostatin receptor imaging. Patients will be randomized into two arms: 1. control arm: regimen 177Lu-Dotatate every 8 weeks (q8w) 2. experimental arm: regimen 177Lu-Dotatate every 16 weeks (q16w) Research hypothesis: Less intensive somatostatin-receptor (SST) targeted radioligand therapy (RLT) (7.4 GBq/cycle 177Lu-Dotatate every 16 weeks x 4 cycles) is associated with less severe hematological toxicities and may mitigate the risk to develop therapy-related myeloid neoplasms (t-MN) with similar antitumor efficacy in slowly growing gastrointestinal grade 1-2 NETs.