Caren van Roekel

268 Chapter 10 catheter position and to assess the activity distribution. The latter is necessary to rule out extrahepatic deposition, determine the lung shunt fraction and determine treatment volumes for ordering activity. Usually, the preparatory angiography and scout dose administration precede treatment by 1-2 weeks. However, the question was raised if this can be done in a single day. Possible advantages include time- and cost savings: it saves time for patients, which is especially favorable in patients with rapidly progressive disease or in patients with highly symptomatic disease, for example in patients with hepatic metastases from an insulinoma. A one-day treatment approach can save costs for both patients and hospitals: patients don’t have to travel twice (which is especially convenient for patients who have to travel a long distance) and hospitals have less admission costs. Studies in the three available types of microspheres showed that radioembolization as a single-day procedure is feasible and safe (69-71). In our study on one-day treatment, a disadvantage of this approach was the increased incidence of back pain. As patients have to lie down for many hours (in our study, a median of more than 10 hours), back pain easily occurs. The most important disadvantage however, is that a single-day procedure implies that only predefined dosimetric approaches, such as the body surface area (BSA) and MIRD method, can be used, because activity needs to be pre-ordered and can therefore not be adjusted based on scout dose distribution (72). With the increasing use of personalized treatment strategies, based on the results of the preparatory angiography and scout dose distribution, a one-day treatment strategy may not be preferred to allow for careful treatment planning. Which types of microspheres are available for radioemboliza- tion? Currently, three different types of radioactive microspheres are commercially available: 90 Y resin (SIR-Spheres®, SIRTeX Medical Ltd., Australia), 90 Y glass (TheraSphere®, Boston Scientific, US) and holmium-166 ( 166 Ho) microspheres (Quiremspheres®, Quirem Medical, The Netherlands). The characteristics of these three types of microspheres are listed in Table 1.