Yttrium-90 Microsphere Radioembolotherapy of Hepatic Metastatic Neuroendocrine Carcinomas after Hepatic Arterial Embolization

Hepatic artery radioembolization was performed in a cohort of patients with unresectable neuroendocrine hepatic metastases who exhibited hepatic progression or toxicity despite technically adequate embolization procedures without other reasonable therapeutic options. Eight patients (five men) with a median age of 55.5 years met the study criteria. Infusions of yttrium-90 resin microspheres were performed in a lobar fashion. Standard clinical, laboratory, and imaging follow-up was performed. Median hepatic parenchyma replacement by tumor was 55% (range, 25%-60%). Twelve 90Y resin microsphere infusions were performed, and the median delivered activity was 33.25 mCi (range, 23-55 mCi). One partial response, four cases of disease stabilization, and three cases of progressive disease were noted. No cases of radiation-induced liver disease occurred. Median survival times were 14 months (range, 3-15 months) from the time of 90Y microsphere treatment and 36.5 months (range, 16-105 months) from the time of diagnosis of hepatic metastases. In this cohort, 90Y microsphere radioembolization of neuroendocrine hepatic metastases was not precluded by previous nonradioactive embolization procedures, but the effectiveness in this population requires further investigation.