Outcomes After Transarterial Embolization of Neuroendocrine Tumor Liver Metastases Using Spherical Particles of Different Sizes

PurposeTo evaluate initial response and overall survival of neuroendocrine tumor (NET) liver metastases initially treated with transarterial embolization (TAE) using spherical particles of different sizes.MethodsA single-institution retrospective review was performed of 160 patients with NET liver metastases initially treated with TAE using <100 mu m (n=77) or only100 mu m (n=83) spherical particles. For each patient, we evaluated: initial response by mRECIST, time to progression, overall survival, complications, primary site, tumor grade and degree of differentiation, volume of liver disease, extrahepatic disease, NET-related symptoms, comorbidities, Child-Pugh score, performance status, lobar versus selective embolization, and arteriovenous shunting.ResultsInitial response was higher for TAE using particles <100 versus TAE using only particles 100m (64 vs 42%, p=0.007). Multivariate logistic regression showed that use of particles <100m and liver <50% replaced with tumor were independent predictors of a better initial response rate. There was no difference in major or minor complications between the two particle size groups. Median overall survival after TAE was 55months for well- to moderately differentiated NET and 13months for poorly differentiated or undifferentiated NET. There was no significant difference in survival between TAE patients treated with <100 versus only 100-m particles.ConclusionNET patients treated with TAE using particles <100m had better initial response, but the same overall survival, compared to TAE using only particles 100m.