David S. Lu, MD (he/him/his)
Professor of Radiology, and Surgery
David Geffen School of Medicine at UCLA
Steven Raman, MD, FSAR, FSIR
Professor of Radiology, Urology and Surgery
David Geffen School of Medicine At UCLA
Liver tumors were induced at an 83.3% (20/24) success rate. Treated tumors decreased by an average 7% in volume across all treatment modalities on 1-week follow-up imaging. Off-target tumors increased by volume by 71.7% with IRE, 13.6% with MWA and 1.4% with cryoablation. On 1-week blood samples, IRE treated pigs demonstrated lower circulating concentrations of pro-inflammatory IL-2 cytokines when compared to cryoablation (10.9 vs 40.7 pg/mL; p=0.051). There was no difference in IL-2 levels between MWA and cryoablation-treated pigs (40.7 vs 42.4 pg/mL; p=0.97).
The pro- and anti-tumor immune response is dependent on the type of ablation modality. IRE had the lowest levels of inflammatory marker IL-2 and the lowest degree of tumor control in off target tumors at the one-week time point. Modulating inflammatory pathways via these cytokines after IRE may potentially play a role in amplifying the abscopal effect in liver tumors.