4.2. Management

Radioembolization is usually performed in an outpatient setting. Pre-procedural angiogram and nuclear medicine Technetium macro-aggregated albumin (Tc-MAA) scan are necessary prior to treatment.

The angiogram determines anatomy including replaced right or left hepatic arteries. The origin of the right gastric should be identified. Coil embolization of any gastro-intestinal vessels originating from the right or left hepatic artery must be performed. Tc-MAA is needed to assess lung shunt fraction and consequently lung dose as tumor vascularity often have arteriovenous shunts. The lungs dose cannot exceed 30 Gy in one treatment session or 50 Gy cumulative dose [40]. Several strategies have been employed with high lung shunt fraction including no treatment, reduction of SIRsphere dose, bland embolization of the shunt, and balloon occlusion of the hepatic vein during microspheres delivery.

A 7–10 day course of proton pump inhibitors may be given to prevent gastric ulceration.

Post-procedural MRI should be obtained no earlier than 2 months to assess tumor response. In addition, tumor markers and liver function tests are obtained 4–6 weeks post-procedure.

Post-radioembolization syndrome is a constellation of abdominal pain, fatigue, nausea, vomiting, and fever. This is usually managed conservatively with hydration and over the counter medications.

#### 4.3. Complications

Radioembolization induced liver disease (REILD) presents as jaundice, ascites without tumor progression, biliary obstruction, or elevated alkaline phosphatase. Histopathology reveals veno-occlusive disease, sinusoidal congestion, and necrosis. REILD is defined as liver failure within 90 days post-radioembolization or greater than 90 days without tumor progression. Patients with decreased baseline liver function, with whole liver treatments and polychemotherapy are at increased risk [41]. Low-dose steroids and ursodeoxycholic acid can reduce the risk of REILD.

Non-target embolization may also occur with the adverse effects similar to TACE. Gastrointestinal ulceration remains a risk though with careful administration technique and proper coil embolization during work-up, complications are decreased to less than 4% [42]. Radiation pneumonitis if very rare occurring less than 1% and is avoidable with proper work up.

Other rare complications include radiation pancreatitis, dermatitis, cholecystitis or cholangitis. In general, biliary complications occur in less than 10% of cases though patients with polychemotherapy or disrupted ampulla of Vater patients are at increased risk [43].

Vascular complications are also similar to TACE. Patients on bevacizumab (Avastin) and other biologic agents (i.e. cetuximab, aflibercept, etc.) are at increased risk of dissection and rupture so careful technique and use of microcatheters should be employed.

Rarely lymphopenia may occur after glass microsphere radioembolization with greater than 25% decrease in lymphocyte count [43]. Fortunately, no opportunistic infections have been described.
