Segmental Pneumonitis after Radioembolization

Abstract

Radiation pneumonitis, although infrequent, is a dreaded complication of radioembolization (RE) with yttrium-90 ( 90 Y) microspheres (1). Only 6 cases have been reported so far (1,2). It develops when 90 Y microspheres reach the lung filter owing to circumvention of the liver sinusoidal network through the tumor or arteriovenous channels. Risk of pneumonitis increases when the lung shunt frac- tion is > 20% or when the estimated absorbed dose by the lungs is > 30 Gy (3). During 90 Y RE, occlusion of extrahepatic arterial branches that feed the tumor from the systemic vasculature is commonly performed with the aim to redistribute tumor afferents and administer the treatment through the hepatic arteries.