Peptide receptor radionuclide therapy (prrt) for neuroendocrine neoplasms: real-world outcomes and safety profile across diverse sites in Brazil

Abstract

OBJECTIVE: Peptide receptor radionuclide therapy (PRRT) has established itself as a pivotal first-line treatment option for gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs). The first approval was based on the NETTER-1 trial focusing on midgut neuroendocrine tumors and, more recently, therapeutic indications have been expanded with the publication of NETTER-2 trial. Despite these limited approvals the clinical application extends to various neuroendocrine neoplasms (NEN) types. This study presents real-world outcomes and implementation data from four tertiary treatment centers in Brazil, highlighting the safety profile of PRRT across different NEN sites. METHODS: A retrospective analysis encompassing January 2007 to January 2021 was conducted across four Brazilian hospitals, involving 173 histologically confirmed NEN patients treated with 177Lu-dotatate PRRT. Clinician-evaluated data encompassed demographics, efficacy, and toxicity. RESULTS: Of the 171 patients (89 female- 52%), the median number of 177Lu- dotatate treatments was four (range 1-8). Tumor localization included 77% GEP- NENs, 42% midgut NENs, 7% lung and 10% other sites (breast, prostate, adrenal, ovary, cervix, paraganglioma, kidney, neuroblastoma, thymus, gallbladder, thyroid). Notably, most common significant toxicities (G3/G4) were renal- 5 patients- and 5 hematological - 6 patients. The majority of the treated patients (48%) had partial response. CONCLUSIONS: We observed an important utilization in non-midgut sites, such as pancreas and foregut. Despite this, PRRT exhibited a significantly low incidence of treatment-related toxicity in our cohort, establishing its safety with minimal hematological and renal effects. Real-world utilization of PRRT includes patients with varying disease stages, prior treatments, and a safety profile in response to therapy.