Intra-Arterial Treatment with 90Yttrium Microspheres in Treatment-Refractory and Unresectable Liver Metastases of Neuroendocrine Tumors and the Use of 111In-Octreotide Scintigraphy in the Evaluation of Treatment Response

Purpose: The aim of this study was to examine the efficacy of intra-arterial (90)Yttrium treatment in the management of unresectable hepatic neuroendocrine tumors (NET) metastases unresponsive to treatment and the role of In-111-octreotide scintigraphy in the evaluation of treatment response. Methods: Thirteen (13) patients with a mean age of 53.3 years not eligible for surgical treatment were included. Before the procedure, routine tests for renal/hepatic functions and bilirubin levels as well as (99)mTc-macroaggregated albumin test to detect any leakage to the lungs were done. Treatment doses were calculated using body surface area method and all patients received Y-90 resin microspheres through hepatic artery catheter. Abdominopelvic computed tomography (CT) and In-111-octreotide scintigraphy were done before and after treatment. Patients were divided into two groups based on their treatment response as assessed by either In-111-octreotide scintigraphy or CT: group 1, responders; group 2, nonresponders. Results: For all patients, 1-year survival rate and overall survival was 84.7% and 20 months, respectively. Based on In-111-octreotide scintigraphy findings, 1-year survival rate was 90% and 66.7% for responders and nonresponders, respectively, whereas corresponding overall survival was 21.3 months and 15.3 months. Survival data based on CT findings were as follows: 1-year survival rate, responders, 80%; nonresponders, 100%; overall survival, responders, 20.4 months, nonresponders, 18.5 months. Conclusions: Intra-arterial treatment with Y-90 has survival benefits in treatment-refractory liver metastases from NETs and it could be used in these patients. Since it is a functional imaging method, In-111-octreotide scintigraphy may be better discriminates patients responding to treatment from patients not responding.