Time toxicity of lutetium 177 in gastroenteropancreatic neuroendocrine tumours

We aim to investigate the time toxicity of patients with gastroenteropancreatic neuroendocrine tumours treated with Lutetium-177 Dotatate in a single institution.

This is a retrospective cohort study.

All patients with gastroenteropancreatic neuroendocrine tumours treated with Lutetium-177 Dotatate at the Alexander Fleming Institute were included. Our primary endpoint was to evaluate time toxicity, which accounted for every day that the patient had contact with any department of any healthcare institution.

Our cohort included 21 patients with metastatic disease, female sex 86%, and a median age of 55 (IQR 44-63). The primary tumour site was the small intestine in 47.6% of the cases. The median number of previous systemic treatments for advanced disease was two (IQR 2-3). The overall response rate was 19%, and 66.6% had clinical benefit. The median calculated 'time toxicity' was 11 days (IQR 8-18), representing 5.7% of the total treatment duration. The main contributors to time toxicity included infusion days, blood draws, radiological scans, and hospitalisations (median of 4 days for each).

Lutetium-177 Dotatate treatment for gastroenteropancreatic neuroendocrine tumours was associated with low time toxicity, excellent tolerability, a good response and prolonged PFS, of which the median was not reached in the short follow-up we present. Newer treatments with different mechanisms of action provide longer survival and widen the landscape of choices. Understanding new clinical endpoints is important for the transition into a more modern clinical practice, strengthening personalised and patient-oriented strategies.