Caren van Roekel

264 Chapter 10 Currently, radioembolization is indicated in the salvage setting. Studies on radioembolization in this stage of disease found median overall survival rates ranging from 5.7-12.8 months, with a median overall survival of 10 months (44, 52, 53). As median overall survival in chemotherapy-refractory, unresectable patients was reported to be around 6 months, radioembolization seems to offer a meaningful survival benefit (53). The most common toxicity after radioembolization is the so-called post-embolization syndrome, which consists of nausea, fatigue, abdominal pain and fever and occurs within 4-6 weeks after treatment, but is usually mild (51, 54). The most severe, possibly lethal complication is radioembolization-induced liver disease (REILD). REILD occurs in <5% of patients and is characterized by hyperbilirubinemia, ascites, hypoalbuminemia and liver failure (55). Other complications may result from extrahepatic activity deposition, such as radiation cholecystitis or radiation pneumonitis. In the MORE study, the safety and overall survival associated with 90 Y-radioembolization (resin microspheres) was assessed in colorectal cancer patients with liver-dominant, unresectable metastases who were chemorefractory or not suitable for systemic therapy (56). A total of 606 patients were included. The most common CTCAE grade 3 or higher adverse events were abdominal pain (6.1%), fatigue (5.5%), hyperbilirubinemia (5.4%) and there were five patients (0.8%) with hepatic failure. Overall survival was 10 months (95%CI 9.2-11.8 months). Prognostic factors for survival included performance status, a large tumor burden, liver function, presence of anemia at baseline, lung shunt fraction and number of previous chemotherapy lines (45, 56). This study showed that even after disease progression after several lines of systemic therapy, 90 Y-radioembolization can offer a survival benefit (compared to patients treated with systemic therapy or best supportive care in similar settings), with limited side effects. Outside the palliative setting, radioembolization is more and more used as a bridge to surgery. In patients with unilobar hepatic metastases, hemihepatectomy can be performed. However, in many cases, the function of the future liver remnant is not good enough to allow for surgery. Currently, portal vein embolization is often performed to induce hypertrophy of the future liver remnant. However, radioembolization of one liver lobe can also induce sufficient hypertrophy of the untreated lobe, albeit not as fast as portal vein embolization (PVE). An advantage of using radioembolization is that it not