Caren van Roekel

41 Radioembolization dose reductions of 20%, 40% and 100% if the LSF exceeds 10%, 15% or 20% (79). A maximum tolerated dose of 30 Gy in one treatment or 50 Gy in sequential treatments to the lungs is widely used, but due to the very low incidence of radiation pneumonitis, it is difficult to establish an endorsed threshold. Sangro et al. propose to refrain from treatment with radioembolization if the LSF is ≥15%, rather than adjusting the amount of injected activity. However, since lung shunt doses are often overestimated, this would result in withholding patients from what can be their last treatment option. Radiation pneumonitis is characterized by bilateral symmetric ill-defined patchy opacities and ground- glass nodularities on CT (Figure 7a-d). Treatment consists of steroids and supportive measures (79). FIGURE 7A-D. Figure 7a: cone-beam CT of 65-year old woman with HCC, with arteriovenous shunt (arrow). Figure 7b shows the lung shunt on 90 Y-PET. Figure 7c-d show high-resolution CT images of the lungs with ground-glass nodularities and fibrosis. Other complications that may arise are portal hypertension and biliary tree damage. Portal hypertension can develop months to years after 2