Fig. 1: In vitro and in vivo evaluation of MTPA.

a In a gelatin tissue phantom, various concentrations of ICG were illuminated with an 808 nm NIR laser at 2 W. A thermocouple adjacent to the ICG was used to acquire continuous temperature data. ICG-specific temperature generation upon illumination by NIR light was achievable even at low ICG concentrations. b Time course study of ICG localization in an orthotopic, syngeneic rat model of HCC revealed improved TBRs at late timepoints, with a TBR of ~4:1 when imaged at 96 hours post i.v. injection. N = 4 animals per group. c In vivo illumination of orthotopic HCC tumors with a 785 nm laser at 450 mW in animals injected with i.v. ICG 96 hours prior generated ablative temperatures within the tumor but not in the adjacent liver parenchyma, thus highlighting the tumor specificity of MTPA. N = 4 animals. d MRI images prior to ablation (pre, T2-weighted image) demonstrates a small focal HCC. Following MTPA, a zone of ablation completely surrounds the lesion (post, T1-weighted post-contrast fat-saturated image). Histologic examination following MTPA of an animal with two focal orthotopic HCC tumors, one of which was targeted with MTPA, shows a zone of ablation encompassing the entire treated lesion.