Caren van Roekel

127 One-day treatment in 166 Ho-radioembolization Radioembolization was cancelled in 15 patients due to various reasons: extrahepatic deposition (n=8), suboptimal tumor targeting (n=1), unanticipated vascular anatomy (n=5) and dissection (n=1) (Figure 3). Unanticipated vascular anatomy led to more injection positions needed than anticipated because of arterial branches that were either not identified on the baseline contrast- enhanced CT or that could not be coil-embolized. In 14 patients, the treatment plan was adjusted. Reasons for adjustment were extrahepatic deposition (n=4), suboptimal tumor targeting (n=9), and unanticipated vascular anatomy (n=1). In most cases, adjustment of the therapy plan meant a lobar treatment instead of a whole-liver approach and one of the two ordered vials was discarded. In one case with suboptimal tumor targeting, it was decided to only inject part of the ordered activity (which was done by splitting the activity in our radionuclide laboratory). FIGURE 3. Flowchart of patients who were excluded from one-day 166 Ho- radioembolization and patients whose treatment plans were adjusted. 4