Histotripsy of the prostate: dose effects in a chronic canine model.
OBJECTIVE
To develop the technique of histotripsy ultrasound therapy as a noninvasive treatment for benign prostatic hyperplasia and to examine the histotripsy dose-tissue response effect over time to provide an insight for treatment optimization. We have previously demonstrated the feasibility of prostate histotripsy fractionation in a canine model.


METHODS
Various doses of histotripsy were applied transabdominally to the prostates of 20 canine subjects. Treated prostates were then harvested at interval time points from 0 to 28 days and assessed for histologic treatment response.


RESULTS
The lowest dose applied was found to produce only scattered cellular disruption and necrosis, whereas higher doses produced more significant regions of tissue effect that resulted in sufficient fractionation of tissue so the material could be voided with urination. Urethral tissue was more resistant to the lower histotripsy doses than was parenchymal tissue. Treatment of the urethra at the lowest doses appeared to heal, with minimal long-term sequelae.


CONCLUSIONS
Histotripsy was effective at fractionating parenchymal and urethral tissue in the prostate, in the presence of a sufficient dose. Further development of this technique could lead to a noninvasive method for debulking the prostate to relieve symptoms associated with benign prostatic hyperplasia.
Hall
Timothy L
TL
Department of Urology, University of Michigan, Ann Arbor, Michigan, 4432 Med Sci 1, 1301 Catherine St, Ann Arbor, MI 48109, USA. hallt@umich.edu
Hempel
Christopher R
CR
Wojno
Kirk
K
Xu
Zhen
Z
Cain
Charles A
CA
Roberts
William W
WW
D000818:Animals; D004195:Disease Models, Animal; D004285:Dogs; D008297:Male; D011467:Prostate / Q000473:pathology; D011470:Prostatic Hyperplasia / Q000628:therapy*; D014464:Ultrasonic Therapy / Q000379:methods*