Effect of Substituting 50% Isovue for Sterile Water as the Delivery Medium for SIR-Spheres: Improved Dose Delivery and Decreased Incidence of Stasis.

PURPOSE: The objective of this study was to evaluate the effect of substituting 50% Isovue (Bracco Diagnostics Inc, Monroe Township, NJ) for sterile water on the delivery of Y resin microspheres (SIR-Spheres [Sirtex Medical Limited, Sydney, Australia]).

MATERIALS AND METHODS: The authors retrospectively reviewed all SIR-Spheres radioembolizations at the authors' institution from January 1, 2011, to February 10, 2014. From January 1, 2011, to April 30, 2013, all users performed SIR-Spheres radioembolization per the manufacturer's original instructions using sterile water in the B and D lines and intermittently checking the progress of the embolization by injecting contrast via the B line. Beginning May 1, 2013, a modified technique using Isovue diluted 50% with saline in place of sterile water in both the B and D lines of the infusion set. The authors compared the prepared versus administered activity of Y SIR-Spheres, fluoroscopy time, administration time, and frequency of radioembolizations terminated for stasis when using water versus dilute contrast in the B and D lines.

RESULTS: One hundred seventy-five radioembolizations were performed, 132 (75%) with water as the delivery medium and 43 (25%) with 50% contrast as delivery medium. The mean percentage of the Y activity administered was 98% with contrast versus 87% with water (P < 0.01). More than 95% of cases using contrast resulted in 90% or more delivery of the prepared Y activity versus 59% of cases with water (P < 0.01). For cases using water, 17% were terminated for stasis, whereas 2% (1 case) using contrast was terminated for stasis. The mean Y administration time was 7 minutes with contrast versus 22 minutes with water (P = 0.015). Excluding the 37 cases involving coil embolization, the mean fluoroscopy time was 8.3 minutes with contrast versus 11.5 minutes with water (P < 0.05). No complications occurred with the contrast method; however, there were 4 complications with water, including 1 nontarget gastric ulceration.

CONCLUSIONS: Using dilute contrast as the delivery medium for SIR-Spheres resulted in a significantly greater percentage of the prepared activity administered to the patient with substantially shorter administration time. Termination for stasis occurred less often with dilute contrast. No complications were observed when using dilute contrast, which allowed continuous real-time monitoring of the Y microsphere administration.