Evaluation of the Real-Life Efficacy and Safety of the Treatment with Lutetium-177 Dotatate for Metastatic Neuroendocrine Tumors

<b>Background:</b> Therapy using lutetium-177 dotatate (¹⁷⁷LU) was approved in Europe for the treatment of advanced neuroendocrine tumors (NETs) in 2017. Since then, it has become part of the strategies in the treatment of NETs, making it now possible to evaluate real-life results. <b>Research Design and Methods:</b> Single-arm, retrospective, multicenter, cohort study of all the patients with metastatic NETs treated with ¹⁷⁷LU (four cycles of 200 mCi every 8 weeks) in the two medical centers dedicated to the treatment of NETs from the region of Aragón, Spain, from 2017 to 2024. Descriptive analysis of demographic characteristics, efficacy, and survival analysis were performed using the statistics software Jamovi 2.6.14. <b>Results:</b> Sixty-eight patients were included. The majority were male, and the most frequent primary location was the pancreas. The ORR was 30.9%. The DCR was 88%. The median OS was 47.4 months [95% CI, 25.6-NE]. The median PFS was 26.1 months [95% CI, 18.5-68.3]. High-grade tumors, multiple previous treatments, and pancreatic location presented worse OS. In total, 42.6% presented any grade adverse event (17.2% hematologic, 30.9% GI symptoms). <b>Conclusions:</b> The efficacy of ¹⁷⁷LU in our study is like that observed in similar studies. Acceptable tolerance has been shown. Pancreatic tumors, previous treatments, and higher grades demonstrated worse outcomes. The new research line must consider the use of treatment with ¹⁷⁷LU in earlier lines for metastatic disease as well as its possible use in local or locally advanced disease.