Real-world efficacy of lutetium peptide receptor radionuclide therapy in patients with neuroendocrine tumours

Lutetium peptide receptor radio nuclide therapy (Lu-PRRT) is an effective treatment for progressive, metastatic, somatostatin-receptor-positive, well-differentiated neuroendocrine tumours (WD-NETs). Here, we report a single centre experience of real-world efficacy, long-term side effects, and challenges of this treatment. This was a retrospective analysis. All patients linked with our centre who had Lu-PRRT were included. Clinicopathological data were analysed using descriptive statistics, Kaplan-Meier, and Cox regression. A total of 45 patients had Lu-PRRT, of those 30 (67%) were males, and 13 (29%) were more than 65 years old. The primary site was small intestine in 30 (67%) patients, pancreas in seven (16%) patients, and lung in three (7%) patients. The tumor was grade 1 in 15 (35%) patients, grade 2 in 22 (48%) patients, and grade 3 in six (13%) patients. A total of 41 (91%) patients had liver metastasis, and 20 (44%) patients had carcinoid syndrome. Lu-PRRT was the second-line therapy in all patients. Krenning's score was 4 in 36 (80%) patients and 3 in nine (20%) patients. The median waiting time to start Lu-PRRT therapy was 87 days. The median follow-up was 41 months. A total of 23 (51%) patients had a partial response, 18 (40%) patients had stable disease, and four (9%) patients had progression. None of the patients had a complete response. The median progression-free survival (PFS) was 38 months (95% CI: 25.8-50.1). The median overall survival (OS) was not reached. Nine patients died during follow-up (death from any cause). Prior treatment with targeted therapies or high dose somatostatin analogues were negative predictors of Lu-PRRT outcome (p-values of < .001 and < .045, respectively). There were two serious haematological toxicities, one patient developed acute myeloid leukaemia (AML), and the other developed chronic myeloid leukaemia (CML). Lu-PRRT is an effective second-line treatment for metastatic WD-NETs. The effect of targeted therapies on Lu-PRRT outcome was significant and needs to be clarified in further studies.