Differences in Radiation Activity Between Glass and Resin 90Y Microspheres in Treating Unresectable Hepatic Cancer

Abstract

The purpose of this study was to compare the difference in prescribed radiation activity between glass and resin yttrium-90 (Y) microspheres for radioembolization of unresectable hepatocellular carcinoma (HCC) or liver metastases at a tertiary care teaching institution. The authors performed a retrospective analysis on 126 patients with primary HCC and hepatic metastatic disease from extrahepatic primary cancers who underwent radioembolization with glass or resin particles between 2008 and 2013 at their institution. Radiation activity estimates for prescribed treatments, as well as for the alternate embolization particles, were calculated using commonly employed formulae for both glass and resin particles for all treatments. A total of 217 treatments were performed on 126 patients, with 136 (62.7%) using glass particles and 81 (37.3%) using resin particles. Forty-six (36.5%) patients had metastatic colorectal cancer (CRC), 51 (40.5%) had primary HCC, while 11 (8.7%) had neuroendocrine carcinoma, and 18 (14.3%) had metastases from other primary tumors. The average prescribed activity was 2.66 GBq for glass treatments and 1.06 GBq for resin treatments across all cancer types. When the alternative treatment activity was calculated, activities were projected to decrease by an average of 1.52 GBq per treatment if resin microspheres were used instead of glass microspheres (-52.5%), while activities were projected to increase by an average of 1.57 GBq per treatment if glass microspheres were used instead of resin microspheres (148.9%; p < 0.001). Similar results were seen within each malignancy type and all projected changes were statistically significant (p < 0.001). In conclusion, prescribed radiation activity for radioembolization of unresectable hepatic cancer was significantly lower for resin compared to glass microspheres.

Targeted Radionuclide Therapy: An Evolution Toward Precision Cancer Treatment

“…For either microsphere, the therapeutic activity dosage is calculated on the basis of the relevant package insert information. A recent report suggested that the prescribed radiation activity might be significantly lower for resin than for glass microspheres, which may in part result from their different specific activities [31, 32]. However, this difference in activity does not appear to lead to a significant survival difference between the two types of treatment [33].…”

Microspheres Used in Liver Radioembolization: From Conception to Clinical Effects

“…For glass and PLLA microspheres, the activity planning is based on the Medical Internal Radiation Dose principles and aims to reach a non-toxic dose to the liver [ 35 ]. Compared to 90 Y-resin microspheres, the administered activity is usually threefold higher for 166 Ho-PLLA and 2.5-fold higher for glass microspheres [ 34 , 36 ].…”