Glass vs Resin Microspheres for Intrahepatic Cholangiocarcinoma
Patients with intrahepatic cholangiocarcinoma (ICC) may receive a higher dose to the targeted tumors if Y90 glass microspheres are used rather than resin-based microspheres, researchers reported.
In this retrospective study, researchers evaluated the dose of radiation delivered through glass compared with resin-based Y90-RE in ICC. The study included 10 patients with ICC who underwent Y90-RE. Five patients were treated with glass and 5 with resin microspheres. Two weeks prior to Y90-RE, patients underwent Technetium-99m macro-aggregated albumin (Tc-99m MAA) shunt study.
After Y-90 was administered, Bremsstrahlung SPECT/CT was obtained, and regions of interest (ROIs) were segmented around the targeted tumor and the liver. Tumor and liver volumes, corresponding radioactive counts, and tumor to liver count ratio were calculated and comparisons were made between the glass and resin groups.
Results indicated that the glass group had a mean hepatopulmonary shunt fraction of 7.1%, while the resin group was 6.2%, with no extrahepatic activity in either group. Neither group showed a difference in the activity and tumor uptake of administered Tc-99m MAA.
In the glass group, there was a higher mean administered activity of Y90 than in the resin group. Additionally, the tumor Y90 uptake was significantly higher in the glass group (41.3%) than in the resin group (33.5%). These differences corresponded with the mean tumor doses in each group. Patients in the glass group also had a significantly higher tumor to normal liver parenchyma Y90 dose ratio than those in the resin group.
The researchers concluded that both glass and resin microsphere are feasible and safe for ICC treatment. However, “difference in dose of Y90 delivered to the targeted tumors should be clinically considered while choosing the microsphere type,” they stated.
Nezami N, Kokabi N, Camacho JC, Schuster DM, Xing M, Kim HS. Y90 radioembolization dosimetry using a simple semi-quantitative method in intrahepatic cholangiocarcinoma: Glass versus resin microspheres. Nucl Med Biol. 2018 Jan 16;59:22-28. doi: 10.1016/j.nucmedbio.2018.01.001. [Epub ahead of print]