To explore the efficacy and adverse effects of ¹⁷⁷Lu-1, 4, 7, 10-tetraazacyclododecane-1, 4, 7, 10-tetraacetic acid-D-Phe1-Tyr3-Thr8-octreotide (DOTATATE) in patients with neuroendocrine neoplasms (NEN).

From 2019 to June 2021, 36 patients (26 males, 10 females; age (43.5±12.9) years) with metastatic NEN who were treated with ¹⁷⁷Lu-DOTATATE in the Affiliated Hospital of Southwest Medical University were retrospectively analyzed. Toxicities were assessed by using the common terminology criteria for adverse events (CTCAE) version 5.0. Disease progression and tumor response were determined according to the response evaluation criteria in solid tumors (RECIST) version 1.1. Prognostic factors for progression-free survival (PFS) and overall survival (OS) were analyzed by Cox proportional-hazards model.

Of 36 patients, the median follow-up time was 19.8 months, the median PFS was 24 months, and the median OS was not reached. The WHO grade Ⅲ (hazard ratio (HR)=3.59, 95% CI: 1.10-11.73, P=0.025; OS: HR=7.85, 95% CI: 1.50-41.10, P=0.004), ¹⁸F-FDG positive (PFS: HR=3.05, 95% CI: 1.04-8.93, P=0.033; OS: HR=5.90, 95% CI: 1.04-33.49, P=0.025), and received systemic chemotherapy before peptide receptor radionuclide therapy (PRRT) (PFS: HR=2.79, 95% CI: 1.01-7.73, P=0.039; OS: HR=5.56, 95% CI: 1.01-30.57, P=0.026) were prognostic factors for PFS and OS. Transient side effects included fatigue (27.8%, 10/36), nausea (5.6%, 2/36), and the most common laboratory toxicities were lymphocytopenia (11.1%, 4/36), followed by mild renal toxicity (8.3%, 3/36) and mild liver injury (5.6%, 2/36).

PRRT with ¹⁷⁷Lu-DOTATATE is an effective and well-tolerated treatment in patients with NEN. PFS and OS are shorter in patients who are WHO grade Ⅲ NEN, ¹⁸F-FDG positive, and received systemic chemotherapy before PRRT.

Neuroendocrine tumors; Receptors, peptide; Organometallic compounds; Isotope labeling; Lutetium