CIO 2022-26 Outcomes of Radioembolization With Different Y90 Microspheres in the Same Patient With Colorectal Liver Metastases

Purpose: To compare the outcomes of Yttrium-90 glass (GM) versus resin-based microsphere (RM) transarterial radioembolization treatment (TARE) in colorectal cancer liver metastases (CRCLM) in patients who received glass microspheres (GM) in one hepatic lobe and resin microspheres (RM) in the contralateral hepatic lobe.

Methods: Our Institutional Review Board-approved, single-center, retrospective study identified seven patients who underwent GM TARE in one hepatic lobe and RM TARE in the contralateral lobe between 2017 and 2021. Bilobar salvage TARE was the consensus treatment option for all patients after multidisciplinary tumor board discussion. The primary stage of the colorectal cancer was stage III in 2 patients  and stage IV in 5 patients. The mean age was 65.1±8.2 years (female 61.0±9.8, male: 68.2±5.0) at the time of the first TARE. 28.6% (2/7) of the patients were alive at the time of the analysis. All patients underwent clinical and imaging follow up per institutional standard of care. Adverse events were evaluated with Common Terminology Criteria for Adverse Events (CTCAE) grading system and tumor response was analyzed by RECIST.

Results: The technical success rate was 100%. The median overall survival from the first TARE was 10.1 months (95% CI 6.5-18.1 months). There were 7 Grade 1 or 2 adverse events. The delivered dose was significantly higher with GM versus RM (116.3±8.3 Gy versus 35.9±10.0 Gy, p=0.009), however there was no significant difference in the number of delivered spheres per treated liver volume (7823±4289 vs 8734±2605 spheres/ml, respectively, p=0.602). The median liver progression free survival was 88 days (95% CI 46.4-209.9 days) with GM and 99 days (95%CI 67.9-166.6 days) in the RM treated lobes(p=0.769). The best responses with GM were stable disease (SD) in four patients and progressive disease (PD) in three patients compared with two partial response (PR), three SD, and two PD after RM TARE.

Conclusion: TARE is a safe and effective salvage therapy in the treatment of CRCLM independent of the type of microspheres utilized.