Kinetic analysis of contralateral liver hypertrophy after radioembolization of primary and metastatic liver tumors.

BACKGROUND: Radioembolization induces liver hypertrophy, although the extent and rate of hypertrophy are unknown. Our goal was to examine the kinetics of contralateral liver hypertrophy after transarterial radioembolization.

METHODS: A retrospective study (2010-2014) of treatment-naïve patients with primary/secondary liver malignancies undergoing right lobe radioembolization was performed. Computed tomography volumetry was performed before and 1, 3, and 6 months after radioembolization. Outcomes of interest were left lobe (standardized future liver remnant) degree of hypertrophy, kinetic growth rate, and ability to reach goal standardized future liver remnant ≥40%. Medians were compared with the Kruskall-Wallis test. Time to event analysis was used to estimate time to reach goal standardized future liver remnant.

RESULTS: In the study, 25 patients were included. At 1, 3, and 6 months, median degree of hypertrophy was 4%, 8%, and 12% (P < .001), degree of hypertrophy relative to baseline future liver remnants was 11%, 17%, and 31% (P = .015), and kinetic growth rate was 0.8%, 0.5%, and 0.4%/week (P = .002). In patients with baseline standardized future liver remnant <40% (N= 16), median time to reach standardized future liver remnant ≥40% was 7.3 months, with 75% accomplishing standardized future liver remnant ≥40% at 8.2 months.

CONCLUSION: Radioembolization induces hypertrophy of the contralateral lobe to a similar extent as existing methods, although at a lower rate. The role of radioembolization as a dual therapy (neoadjuvant and hypetrophy-inducing) for selected patients needs to be studied. (Surgery 2017;160:XXX-XXX.).