Radioembolization with 90Y Resin Microspheres of Neuroendocrine Liver Metastases: International Multicenter Study on Efficacy and Toxicity

Radioembolization of liver metastases of neuroendocrine neoplasms (NEN) has shown promising results; however, the current literature is of limited quality. A large international, multicentre retrospective study was designed to address several shortcomings of the current literature. 244 NEN patients with different NEN grades were included. Primary outcome parameters were radiologic response 3 and 6 months after treatment according to RECIST 1.1 and mRECIST. Secondary outcome parameters included clinical response, clinical and biochemical toxicities. Radioembolization resulted in CR in 2%, PR in 14%, SD in 75% and PD 9% according to RECIST 1.1 and in CR in 8%, PR in 35%, SD in 48% and PD in 9% according to mRECIST. Objective response rates improved over time in 20% and 26% according to RECIST 1.1. and mRECIST, respectively. Most common new grade 3–4 biochemical toxicity was lymphocytopenia (6.7%). No unexpected clinical toxicities occurred. Radioembolization-specific complications occurred in