Feasibility and Effectiveness of Yttrium-90 Radioembolization in Normal Lung Parenchyma: A Preclinical Study in Rabbits with Pathological Correlation to Absorbed Dose.

This study investigated the effects of yttrium-90 (90Y) radioembolization in 8 rabbits, focusing on delivery accuracy, dosimetry, and pathological outcomes. 90Y was successfully delivered angiographically targeted via the pulmonary lower basal segmental arteries to all rabbits, with confirmation via positron emission tomography (PET)/computed tomography (CT) imaging and a lung target median of the mean dose of 132.1 Gy (range, 11.2-262.3 Gy). Pathological analysis in all surviving subjects revealed complete necrosis of the irradiated segments, with associated inflammation in adjacent nonirradiated tissue. Radiological follow-up with CT scan showed triangular fibrosis in 6 rabbits at 1 month, progressing to fibrosis at 3 months. Dosimetry analysis confirmed dose distribution to the targeted lung regions. Of 8 rabbits, 1 died intraprocedurally, and another died 1.5 weeks after the procedure for unknown reasons. The remaining rabbits had no severe adverse events, with 1 case of pleural effusion resolving with no intervention at 3 months. The study demonstrated the feasibility of 90Y delivery to the lungs.