Caren van Roekel

130 Chapter 4 was delivered in a predetermined number of vials and could not be changed after the simulation procedure. Unexpected findings in activity distribution and vascular anatomy led to exclusion from treatment or adjustment of the treatment plan. Other disadvantages of a one-day treatment protocol include back pain. Fortunately, this pain resolved the next day in all cases and was probably caused by the long time that the patients had to lie supine, partly on uncomfortable angio- or SPECT-tables. Gates et al. and Gabr et al. described the feasibility of single-session glass 90 Y-microspheres radioembolization. In their studies, a total of 78 patients were treated in one day. In all patients selected for this procedure, treatment was successful. The authors ordered multiple vials per patient without additional costs, allowing for some flexibility (5, 6). Recently, Li et al. described a same-day treatment approach with resin 90 Y-microspheres radioembolization. Twenty-six patients were treated and all planned cases were technically successful. Based on pretreatment angiography, the planned resin 90 Y-microspheres treatment activity was changed in only one case. This was feasible because with resin 90 Y-microspheres, the patient-specific activity always needs to be drawn from a shipping vial containing approximately 3.0 GBq (4). In these three studies on one-day 90 Y-radioembolization, clinical adverse events during treatment day were not reported. Furthermore, most patients received either selective lobar treatment or superselective segmental treatment, lowering the chance of treatment adjustments (4, 5, 12). This is in contrast to our patient population who mostly received bilobar treatment from multiple injection sites. A one-day treatment approach implies that only pretreatment dosimetric approaches, such as the body surface area (BSA) and MIRD method, are feasible (13). These predefined dosimetric approaches have many caveats and commonly lead to under- or overdosage (14-18). Compared with standard dosimetric approaches, a fully personalized treatment approach can lead to a better outcome, as was shown in a recent study in HCC patients (19).