Efficacy and safety of peptide receptor radionuclide therapy in metastatic neuroendocrine tumour: Malaysian single institution retrospective analysis

PRRT has been recommended as a treatment option in metastatic SSTR+ve GEP-NETs, thoracic-NETs, and pheochromocytomas/paragangliomas. Seven-three NET patients who received either ¹⁷⁷Lu-DOTA-TATE or ⁹⁰Y-DOTA-TOC in a single institution in Malaysia from Mar 2018 to Mar 2020 were evaluated for treatment outcome. Patients were either local or from South-East Asia and East Asia countries. Progression was determined by RECIST 1.1. Toxicities were assessed using CTCAE. Sixty patients are from GEP-NET; 6 thoracic-NET; 5 paraganglioma/ pheochromocytomas and 2 unknown primary. Most NETs are G1 (19.2%) and G2 (60.3%). Twenty-nine (39.7%) of patients received >2 medical therapy + liver directed therapy prior PRRT. Thirtynine (53.4%) patients received 2-4 cycles of PRRT; whereas 34.2% received >4 cycles. Twelve (16.4%) patients received either 1 or 2 courses of PRCRT. Nearly 1/3 patients received alternating ¹⁷⁷Lu-/⁹⁰Y-PRRT. Objective response rate (ORR) in all NETs patients was 47.0%, whereas disease control rate (DCR) was 83.3%. In GEP-NETs, 55.6% patients achieved ORR and 88.9% achieved DCR. With regards to adverse effect, only one patient developed Grade 3 bicytopaenia who required transfusion and thrombopoietin. No renal toxicity was identified including 4 patients initially presented with Stage 2 and 3 CKD. One patient developed Grade 3 liver toxicity but recovered after symptomatic treatment. Three (4.1%) patients developed transient vomiting during radiopharmaceutical infusion. In this small cohort, PRRT demonstrates high ORR and DCR in these parts of Asian population. PRRT is well-tolerated. In the follow-up period, rare incidence of Grade 3/4 haematological toxicity and no renal toxicity are observed. (author)