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.