Acoustic Cavitation Enhances Focused Ultrasound Ablation with Phase-Shift Inorganic Perfluorohexane Nanoemulsions: An In Vitro Study Using a Clinical Device

الملخص EN

Purpose.

To investigate whether acoustic cavitation could increase the evaporation of a phase-shift inorganic perfluorohexane (PFH) nanoemulsion and enhance high intensity focused ultrasound (HIFU) ablation.

Materials and Methods.

PFH was encapsulated by mesoporous silica nanocapsule (MSNC) to form a nanometer-sized droplet (MSNC-PFH).

It was added to a tissue-mimicking phantom, whereas phosphate buffered saline (PBS) was added as a control (PBS-control).

HIFU ( P a c = 15 0 W, t = 5 / 10 s) exposures were performed in both phantoms with various duty cycles (DC).

US images, temperature, and cavitation emissions were recorded during HIFU exposure.

HIFU-induced lesions were measured and calculated.

Results.

Compared to PBS-control, MSNC-PFH nanoemulsion could significantly increase the volume of HIFU-induced lesion ( P < 0.01 ).

Peak temperatures were 78.16 ± 5.64°C at a DC of 100%, 70.17 ± 6.43°C at 10%, 53.17 ± 4.54°C at 5%, and 42.00 ± 5.55°C at 2%, respectively.

Inertial cavitation was much stronger in the pulsed-HIFU than that in the continuous-wave HIFU exposure.

Compared to 100%-DC exposure, the mean volume of lesion induced by 5 s exposure at 10%-DC was significantly larger, but smaller at 2%-DC.

Conclusions.

MSNC-PFH nanoemulsion can significantly enhance HIFU ablation.

Appropriate pulsed-HIFU exposure could significantly increase the volume of lesion and reduce total US energy required for HIFU ablation.