ESTRO 2023 - Abstract Book

S1095

Digital Posters

ESTRO 2023

Conclusion SRT represents a valid treatment for oligometastatic esophagogastric adenocarcinoma, with promising LC and OS at 3 years. CR correlated with PFS and OS, while metachronous metastasis and a good PS correlated with a better PFS. Future studies are needed to study the integration between SRT and systemic therapies.

PO-1365 Lutetium-177 Dotatate peptide receptor radionuclide therapy outcomes for neuroendocrine tumours

M. AlHilali 1 , J. Carberry 1 , A. Challis 2 , P. Atherton 1

1 The Newcastle upon Tyne Hospitals NHS Foundation Trust, Northern Centre for Cancer Care, Newcastle upon Tyne, United Kingdom; 2 The Newcastle upon Tyne Hospitals NHS Foundation Trust, Nuclear Medicine, Newcastle upon Tyne, United Kingdom Purpose or Objective Peptide receptor radionuclide therapy (PRRT) is a molecular radiotherapeutic modality in which ligands for somatostatin receptors are attached to therapeutic radionuclides to target neuroendocrine tumour cells. The Neuroendocrine Tumours Therapy (NETTER-1) trial [1] demonstrated 11.7 month difference in median overall survival (OS) benefit with Lutetium 177 Dotatate treatment (Median OS 48.0 months) versus high-dose long-acting octreotide (Median OS 36.3 months) in patients with advanced midgut neuroendocrine tumours (NETs). This might be clinically relevant despite final overall survival not reaching statistical significance. We designed our audit to compare our cancer centre’s practice and outcome with the National Institute for Health and Care Excellence (NICE) guidance [2] and the NETTER-1 trial findings. Materials and Methods The data was collected from 83 patients who had well-differentiated, metastatic, gastroenteropancreatic neuroendocrine tumours that had started receiving Lutetium-177 Dotatate between August 2019 and September 2022 in the North East and North Cumbria regions of England. The primary outcome measure was overall survival. Results All patients met NICE eligibility criteria for Lutetium-177 Dotatate treatment. Twenty-four patients had grade 1 NETs. Fifty nine patients had grade 2 NETs. Median OS for grades 1 and 2 NETs was not reached with 64.9% of patients alive at 33.1 months (Figure 1). Median OS for grade 1 NETs was not reached with 72.7% of patients alive at 33.1 months. Median OS for grade 2 NETs was not reached with 61.4% of patients alive at 31 months. Eighteen patients had pancreatic primaries. Sixty five patients had gastrointestinal primaries. There was no significant difference in survival between pancreatic and gastrointestinal NETs. Nine patients stopped before completing all cycles of treatment due to disease progression or toxicity. Three patients stopped due to mid-treatment disease progression. Two patients stopped due to pancytopenia, 2 due to thrombocytopenia, 1 due to congestive enteropathy and 1 due to renal toxicity.