Histotripsy of the Prostate: Dose Effects in a Chronic Canine Model

Abstract

Objectives-This work aims to develop the technique of histotripsy ultrasound therapy as a noninvasive treatment for benign prostatic hyperplasia (BPH). We have previously demonstrated the feasibility of prostate histotripsy fractionation in a canine model. The purpose of this paper is to examine the histotripsy dose -tissue response effect over time to provide insight for treatment optimization.Methods-Various doses of histotripsy were applied trans-abdominally to the prostates of 20 canine subjects. Treated prostates were then harvested at interval time points from zero to 28 days and assessed for histologic treatment response.

Histotripsy Homogenization of the Prostate: Thresholds for Cavitation Damage of Periprostatic Structures

“…4 It has also been established that a greater histotripsy dose is needed to fractionate prostate urethra and periurethral stroma than prostate glandular tissue. 12 These findings have led to the hypothesis that the extent of damage from histotripsy is inversely related to the collagen and connective tissue content of the targeted structures. The architectural structure may also play a role in how resistant a tissue is to histotripsy damage.…”

Endoscopic Assessment and Prediction of Prostate Urethral Disintegration After Histotripsy Treatment in a Canine Model

“…As the tissue is converted to homogenate, the US appearance becomes progressively hypoechoic. [8][9][10][11] Transabdominal histotripsy of the prostate is safe and effective in an in vivo canine BPH model, 12 producing dosedependent tissue debulking of the adenomatous BPH tissue 13 with minimal hematuria, even in an anticoagulated model. 14 The strategy for the development of histotripsy therapy for BPH is to produce a TURP-like defect.…”

Ultrasound-guided tissue fractionation by high intensity focused ultrasound in an in vivo porcine liver model

“…We term the approach described above as "boiling histotripsy," in contrast to the previously reported HIFU procedure called "histotripsy," in which much shorter (microsecond-as opposed to millisecond-duration) pulses are used to generate a cavitation cloud in tissue and the activity of the cloud (as opposed to a boiling bubble) is used for tissue erosion (15). Cavitation-cloud histotripsy has been recently demonstrated in vivo for the fragmentation of rabbit kidney (16), canine prostate (17), and porcine liver (18). The treatment was shown to be well tolerated; however, to achieve the focal peak negative pressures sufficient for cavitation cloud formation, very large and highly focused (f-number 0.8) transducers are required, as well as the amplifiers capable of providing extremely high instantaneous power (on the order of several kilowatts).…”