ИСТИНА

Aimed at developing boiling histotripsy (BH) as a non-invasive option for mechanical disruption of kidney tumors, this work quantitatively investigated BH dose (BHD) concept in porcine and canine renal tissues in vivo and ex vivo, considering tissue stiffness. Volumetric BH lesions were produced in kidneys using 1.5-MHz 256-element array with tp=1–10ms pulses, 1–15 pulses per point (ppp). Two BHD metrics were assessed: BHD1=ppp, BHD2=tpppp. Young’s modulus of renal compartments (cortex, medulla, sinus) was measured via shear wave elastography (SWE) in vivo vs ex vivo, and before vs after BH. Histology-based disruption scores were assigned to each renal compartment. Results showed in vivo tissue required lower doses than ex vivo to achieve identical disruption. Cortex (homogeneous, low in collagen), though the same or stiffer than medulla (anisotropic, collagenous), required lower doses, while sinus (fatty, irregular, with abundant collagenous structures) was softer ex vivo but resistant to BH, suggesting that tissue response depends not only on stiffness but also on tissue composition, structural arrangement, and perfusion. BHD1 was relevant for cortex treatment while no tested dose fully disrupted medulla or sinus. SWE-based stiffness reduction post-treatment ex vivo, correlating with BHD, and complete shear wave absence in vivo, demonstrated SWE potential for post-treatment confirmation of BH lesion completeness.