Caren van Roekel

243 Use of an anti-reflux catheter in 166 Ho-radioembolization 0.03 (range 0.0012-0.37) versus 0.04 (range 0.006-0.17) with the standard microcatheter (p=0.53, 95%CI -0.06-0.17) (Figure S1a-d). At a tumor-level, a significant dose-response relationship was established. The mean tumor-absorbed dose in tumors with complete metabolic response was on average 138% higher than in progressive tumors (222 Gy vs. 103Gy, respectively; 95%CI 8-243%). The mean tumor-absorbed dose was 3.8% higher with the use of the anti-reflux catheter than with the standard microcatheter (170 Gy vs. 145 Gy, respectively; 95%CI -37-71%, p=0.89). The odds ratio for metabolic response (complete or partial response) with the use of the anti- reflux catheter was 0.75 (95%CI 0.25-2.25). Tumor- and patient-level metabolic response is summarized in Table S1 and Figure 5. FIGURE 5. Relationship between mean tumor-absorbed dose per patient and metabolic response to treatment at three-months follow-up. The bullets show the mean tumor- absorbed dose per patient. Black vertical lines are the 95%CIs of the mean doses per response category, with the white dot in the middle indicating the mean tumor- absorbed dose per response category. This figure is based on the linear mixed-effects regression model as described in Table S1. 9