Feasibility and Efficacy 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 (Y90) radioembolization in 8 rabbits, focusing on delivery accuracy, dosimetry, and pathological outcomes. Y90 was successfully delivered angiographically targeted via the pulmonary lower basal segmental arteries to all rabbits, with confirmation via PET/CT imaging and a lung target median of the mean dose 132.1Gy (range, 11.2-262.3Gy). Pathological analysis in all surviving subjects revealed complete necrosis of the irradiated segments, with associated inflammation in adjacent non-irradiated tissue. Radiological follow-up with CT-Scan showed triangular fibrosis in six rabbits at one month, progressing to fibrosis at three months. Dosimetry analysis confirmed dose distribution to the targeted lung regions. Out of eight rabbits, one died intra-procedurally, and another died 1.5 weeks post-procedure for unknown reasons. The remaining rabbits had no complications, with one case of pleural effusion resolving with no intervention at 3 months. The study demonstrated the feasibility of Y90 delivery to the lungs.