Radiological and pathological assessment with EOB-MRI after Y90 radiation lobectomy prior to liver resection for hepatocellular carcinoma

Background Radiation lobectomy (RL) utilizes Yttrium-90 (Y90) radioembolization for achieving tumor control and inducing contralateral lobe hypertrophy. Our objective was to evaluate the chronological changes occurring radiologically and histopathologically after Y90 RL. Methods We retrospectively reviewed 22 patients with chronic liver disease who underwent Y90 RL prior to planned liver resection for hepatocellular carcinoma. Gadolinium ethoxybenzyl diethylenetriamine penta-acetic acid (Gd–EOB-DTPA) enhanced magnetic resonance imaging (EOB-MRI) was performed every 3 months. Results Future liver remnant volume (FLRV) significantly increased up to 9 months after Y90 RL. Gd–EOB-DTPA uptake in the treated lobe experienced a 40% reduction in enhancement ratio (ER) during ensuing first 3 months, and never recovered. The reduced ER in the non-tumoral parenchyma was significantly correlated with increased FLRV and FLR (r = 0.41 and r = 0.35, respectively; both p < 0.01). Histopathological evaluation of non-tumor liver tissue found features of sinusoidal obstruction syndrome as an early change after Y90 RL (median 5.7 months) and parenchymal collapse as a late change (mean 11 months). Discussion The reduced uptake of Gd-EOB-DTPA at 3 months post Y90 RL correlates with a significant increase in FLRV prior to liver resection. EOB-MRI evaluation at 3 months can guide future plan of action after Y90 RL.