Regional Yttrium-90 microsphere treatment of surgically unresectable and chemotherapy-refractory metastatic liver carcinoma

Purpose: The aim of this prospective study was to assess the safety and tumor response of intra-arterial Y-90 microspheres for the treatment of surgically unresectable and chemotherapy-refractory liver metastases. Materials and Methods: Forty-six (46) patients with metastatic cancer to the liver from various solid tumors, with tumor progression despite poly chemotherapy, were included. All patients had baseline computed tomography (CT), 18-Fluoro-2-deoxy-D-glucose-positron emission tomography (F-18 FDG-PET), hepatic angiography, and intra-arterial Tc-99m macroaggregated albumin (MAA) scan for the assessment of extrahepatic aberrant perfusion and lung shunting fraction. Twenty-seven (27) and 19 patients were treated with Y-90 glass- or resin-based microspheres (but not both), respectively, on a lobar basis and were monitored over 3 months after last treatment using dedicated attenuation corrected PET. For each patient, regions of interest (ROIs) were drawn along the liver edge to measure total liver standard uptake value (SUV) on axial images covering the entire liver for comparing pre- and post-treatment total liver SUV change. Results: There was a significant decrement in total liver SUV after treatment by either glass- or resin-based microspheres (p = 0.0013 and 0.028, respectively). There was no significant difference in the amplitudes of the mean percentage reduction of tumor metabolism between these two agents (20% ± 25% vs. 10% ± 30% for glass- vs. resin-based microspheres; p = 0.38). None of the patients in the glass-based group developed complications, whereas 3 patients had complications related to hyperbilirubinemia (1 transient and 2 permanent) in the resinbased group. Conclusions: Results suggest that there is significant mean reduction of hepatic metastatic tu-mor load (metabolism), as evaluated objectively by PET after Y-90 microsphere, for the treatment of unresectable metastatic disease to the liver. The Y-90 therapy provides encouraging and safe results by arresting the progression of metastatic cancer to the liver with decreasing tumor metabolism.