13th Annual Global Embolization Symposium & Technologies
Purpose : Y-90 transarterial radioembolization (TARE) is a widely accepted treatment for primary and metastatic liver cancer. Conformality of TARE can be increased with selective administration, but may necessitate smaller lumen or longer microcatheters. Consistent with the Poiseuille equation, increased microcatheter resistance may conceptually result in an increased delivery system residual activity. This study evaluated whether post TARE residual activity is associated with variable microcatheter dimensions.
Material and Methods : Institutional Review Board approval was obtained for this analysis. All patients who underwent glass TARE from January 2017 to July 2018 at a single institution were evaluated. Patients were included if data was available for catheter type, calibration dose vial, day of decay, administration kit and microcatheter residual activity. Post Y90 activity was categorized into positive residual (% > 0) vs no residual (% = 0), >2% and <2% residual, and analyzed for association to catheter type (Cantata, Progreat, Renegade, Prowler), French size(1.9,2.0, 2.4,2.5, 2.8,2.9), end-hole(0.0165, 0.021, 0.022, 0.027in), length (135,150cm), estimated number of particles (0-3, 4-7,8-10 and >10 million) and operators (1-6).
Results : 395 administrations were included. Residuals of 2-5%, 5-10%, 10-15% and >20% were seen in 6%, 1%, 2% and 0%, respectively. A French size of 1.9 (p= 0.003) and 2.9 (p=0.03) had statistically significant associations with positive residual activity. Correlatively, end-hole sizes 0.0165 (p=0.01) and 0.027 (p=0.007) inches were significantly associated with positive residual. Catheter length and number of particles administered were not associated with positive residual activity in the 0% vs non 0% comparison, but 8-10 million of particles were significantly associated with positive residual (p= 0.07) in the <2% vs >2% group. Operators 3 and 6 were associated with a statistically significant residual activity (p = 0.04 and 0.005 respectively).
Conclusions : Residual glass microsphere Y-90 activity is low across all catheter types. Catheter dimensions affect TARE residual, but there are likely contributing factors other than resistance. Infusions via ≤0.021 in. end-hole catheters are feasible without clinically significant residual (>20%) and should be considered in practice.