Efficacy and safety of peptide receptor radionuclide therapy in advanced foregut and hindgut neuroendocrine tumors: a real-world experience from a single institution

Abstract

Objective

Foregut and hindgut neuroendocrine tumors (NETs) contribute significantly to the global NET burden especially in Asian population; however, these cohorts are sparse and underrepresented in current trials assessing peptide receptor radionuclide therapy (PRRT) in gastroenteropancreatic (GEP) NETs. This single-centre study evaluates the efficacy and safety of PRRT in advanced foregut and hindgut NETs.

Methods

Retrospective data evaluation of consecutive patients with biopsy-proven metastatic foregut (gastric, lung and thymic NETs) and hindgut NETs (colorectal, anal and sacral NETs) who underwent PRRT from 2014 to 2024 at a tertiary care hospital was done. Up to four cycles of ¹⁷⁷Lu-DOTATATE (7.4 GBq/cycle) were administered intravenously every 6–8 weeks along with nephroprotection. Interim and end-of-treatment ⁶⁸Ga-DOTANOC PET/CT scans were acquired for response evaluation, based on RECIST v1.1. Objective response rate (ORR), disease control rate (DCR), best biochemical response, toxicity profile, quality-of-life scores, progression-free survival (PFS) and overall survival (OS) were assessed.

Results

Thirty-four patients (median age-56 yrs) with foregut (n = 16) and hindgut (n = 18) NETs received a total of 111 cycles (range 1–4) of ¹⁷⁷Lu-DOTATATE (median cumulative activity 26.5 GBq). The best ORR and DCR were 45% and 80%, median PFS was 29.7 months (95% CI, 20.3–39.1), and the 1- and 5-year OS rates were 93.8% (95% CI, 85.4–100) & 53.6% (95% CI, 28.6–78.6), respectively, after a median follow-up of 45.3 months. Grade 3 adverse events were observed in only five patients.

Conclusion

PRRT appears to be safe and effective treatment modality in advanced foregut and hindgut NETs. More prospective trials are required to validate these findings in larger cohorts.