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.