Caren van Roekel

126 Chapter 4 RESULTS Technical success rate A total of 120 patients were scheduled to undergo treatment with 166 Ho- radioembolization. Sixty-seven patients were included in the HEPAR I and II studies and underwent both a preparatory simulation angiography with administration of 99m Tc-MAA and 166 Ho-scout; the other 53 patients only received 166 Ho-scout. The median interval between the first simulation procedure using 99m Tc-MAA, and the second simulation procedure using 166 Ho-scout was seven days (range 2-21 days). A total of 105 patients completed treatment on the same day (technical success rate 88%). An example case of a successful one-day treatment is shown in Figure 2. FIGURE 2. Example case. A 65-year-old male with neuroendocrine tumor metastases was treated with one-day 166 Ho-radioembolization. Figure a shows the baseline contrast- enhanced CT image with a large hypervascular metastasis in segment 6. Figure b shows the distribution of 166 Ho-scout on SPECT/CT. Figure c shows the contrast-enhanced CT image 3 months after treatment, with evident shrinkage (see annotation) of the metastasis in segment 6. Figure d shows the distribution of the 166 Ho-treatment dose on SPECT/CT.