Quantification of Activity Lost to Delivery-System Residual and Decay in Yttrium-90 Radioembolization

Abstract

Purpose: To measure the decay activity loss and delivery system residual activity loss of yttrium-90 (Y 90 ) radioembolization treatments across resin and glass microsphere activities. Materials and Methods: For Y 90 administrations between December 2009 and June 2017 at the study institution, the prescribed activity, prepared activity, and delivered activity were recorded. Six hundred sixty-two administrations were reviewed—345 glass (0.21–8.52 GBq) and 317 resin (0.18–3.28 GBq). Twenty-five patients (all resin) were excluded for arterial stasis or catheter clogging. The percentage and actual losses of activity lost to decay and to delivery system residual were calculated for glass and resin microspheres. Results: The median time between activity premeasurement and administration was 2.20 hours, resulting in a median activity lost to decay of 0.030 GBq or 2.35%, with no significant difference observed between glass and resin despite differences in preparation (P =.0697). Resin showed significantly higher activity lost to delivery system residual than glass (0.039 GBq vs 0.010 GBq, 3.01% vs 0.61%, P