Selective internal radiation therapy with SIR-Spheres in patients with nonresectable liver tumors

Transarterial embolization of branches of the hepatic artery with biocompatible 90Y-labeled microspheres (SIR-Spheres) is a local treatment modality for patients with liver tumors, which, most recently, has become available in Europe. The aim of this study was to evaluate the feasibility and efficacy of this selective internal radiation therapy (SIRT).

Twenty-three patients with nonresectable hepatic metastases or hepatocellular carcinoma nonresponding to polychemotherapy and/or other local treatment were treated with SIRT. SIR-Spheres (mean activity, 2270 MBq) were administered by gentle intra-arterial infusion in the hepatic artery. A follow-up was documented by fluorodeoxyglucose-positron emission tomography (FDG-PET), course of tumor markers, and computed tomography (CT).

Common minor side-effects were abdominal pain, nausea, and fever. Mild pancreatitis and peptic ulceration were observed once each. Currently, all patients are still alive, with survival times ranging from 11 to 518 days from SIRT up to the present. Three-month follow-up investigations are available in 13 of 23 patients, which, so far, are showing a marked decrease of FDG uptake, a drop of tumor markers, and unchanged or slightly decreasing lesion size (CT) in 10 of 13 patients. Two patients showed stable findings, while another patient showed progressive disease. Long-term follow-up investigations are available in 2 of 23 patients, showing hepatic and extrahepatic progression 6 and 9 months after SIRT.

Our initial experience confirms that SIRT is a promising local therapeutic approach in patients with nonresectable liver tumors which is feasible and has an acceptable toxicity profile. Prospective data on comparing this treatment alone or in combination with other modalities are needed to answer whether long-term survival in this unfavorable stage of disease can be markedly improved.