Resin Versus Glass Microspheres for ⁹⁰Y Transarterial Radioembolization: Comparing Survival in Unresectable Hepatocellular Carcinoma Using Pretreatment Partition Model Dosimetry

The aim of this study was to compare survival of patients treated for unresectable hepatocellular carcinoma (uHCC) with ⁹⁰Y transarterial radioembolization (TARE) using pretreatment partition model dosimetry (PMD). Methods: We performed a retrospective analysis of prospectively collected data on 77 patients consecutively treated (mean age ± SD, 66.4 ± 12.2 y) for uHCC (36 uninodular, 5 multinodular, 36 diffuse) with ⁹⁰Y TARE (41 resin, 36 glass) using pretreatment PMD. Study endpoints were progression-free survival (PFS) and overall survival (OS) assessed by Kaplan–Meier estimates. Several variables including Barcelona Clinic Liver Cancer (BCLC) staging system, tumor size, and serum α-fetoprotein (AFP) level were investigated using Cox proportional hazards regression. Results: The characteristics of 2 groups were comparable with regard to demographic data, comorbidities, Child–Pugh score, BCLC, serum AFP level, and ⁹⁰Y global administered activity. The median follow-up time was 7.7 mo (range, 0.4–50.1 mo). Relapse occurred in 44 patients (57%) at a median of 6 mo (range, 0.4–27.9 mo) after ⁹⁰Y TARE, and 41 patients (53%) died from tumor progression. Comparison between resin and glass microspheres revealed higher but not statistically significantly PFS and OS rates in the ⁹⁰Y resin group than the ⁹⁰Y glass group (resin PFS 6.1 mo [95% confidence interval CI, 4.7–7.4] and glass PFS 5 mo [95% CI, 0.9–9.2], P = 0.53; resin OS 7.7 mo [95% CI, 7.2–8.2] and glass OS 7 mo [95% CI 1.6–12.4], P = 0.77). No significant survival difference between both types of ⁹⁰Y microspheres was observed in any subgroups of patients with early/intermediate or advanced BCLC stages. Among the variables investigated, Cox analyses showed that only in the glass group, the BCLC staging system and the serum AFP level were associated with PFS (P = 0.04) and OS (P = 0.04). Tumor size was a prognostic factor without significant influence on PFS and OS after ⁹⁰Y TARE. Conclusion: Comparison between resin and glass microspheres revealed no significant survival difference in patients treated for uHCC with ⁹⁰Y TARE using pretreatment PMD. Further, larger prospective studies are warranted to confirm these findings.