Current status of peptide receptor radionuclide therapy in grade 1 and 2 gastroenteropancreatic neuroendocrine tumours.

Peptide receptor radionuclide therapy (PRRT) using [¹⁷⁷Lu-DOTA⁰,Tyr³]octreotate (¹⁷⁷Lu-DOTATATE) represents an established treatment modality for somatostatin receptor-positive, locally advanced or metastatic gastroenteropancreatic neuroendocrine tumours (GEP NET) of grade 1 or 2. The studies have demonstrated that four cycles of PRRT with ¹⁷⁷Lu-DOTATATE prolongs progression-free survival and preserves quality of life, in patients with grade 1 and 2 advanced GEP NET. Notably, first-line PRRT using ¹⁷⁷Lu-DOTATATE in grade 2 and 3 GEP NET patients has also shown efficacy and safety. Furthermore, PRRT can ameliorate symptoms in patients with NET-associated functioning syndromes. Although various studies have explored alternative radionuclides for PRRT, none currently meet the criteria for routine clinical implementation. Ongoing research aims to further enhance PRRT, and the results from large clinical trials comparing PRRT with other NET treatments are anticipated, potentially leading to significant modifications in NET treatment strategies and PRRT protocols. The results of these studies are likely to help address existing knowledge gaps in the coming years. This review describes the clinical practice, recent developments and future treatment options of PRRT in patients with grade 1 and 2 GEP NET.