Histotripsy is an extracorporeal ablative technology that utilizes microsecond pulses of intense ultrasound (< 1% duty cycle) to produce nonthermal, mechanical fractionation of targeted tissue. We have previously demonstrated the feasibility of histotripsy prostate ablation. In this study we sought to assess the chronic tissue response, tolerability and safety of histotripsy in a chronic in vivo canine model. Five acute and thirteen chronic canine subjects were anesthetized and treated with histotripsy targeting the prostate. Pulses consisted of 3 cycle bursts of 750 kHz ultrasound at a repetition rate of 300 Hz delivered transabdominally from a highly focused 15 cm aperture array. Transrectal ultrasound imaging provided accurate targeting and real-time monitoring of histotripsy treatment. Prostates were harvested at 0, 7, 28, or 56 days after treatment. Consistent mechanical tissue fractionation and debulking of prostate tissue was seen acutely and at delayed time points without collateral injury. Urothelialization of the treatment cavity was apparent 28 days after treatment. Canine subjects tolerated histotripsy with minimal hematuria or discomfort. Only mild transient lab abnormalities were noted. Histotripsy is a promising non-invasive therapy for prostate tissue fractionation and debulking that appears safe and well tolerated without systemic side effects in the canine model.

Date Published: 23 February 2009
PDF: 8 pages
Proc. SPIE 7161, Photonic Therapeutics and Diagnostics V, 71611N (23 February 2009); doi: 10.1117/12.808516

Published in SPIE Proceedings Vol. 7161:
Photonic Therapeutics and Diagnostics V
Henry Hirschberg M.D.; Brian Jet-Fei Wong M.D.; Kenton W. Gregory M.D.; Reza S. Malek; Nikiforos Kollias; Bernard Choi; Guillermo J. Tearney; Justus F. R. Ilgner; Steen J. Madsen; Laura Marcu; Haishan Zeng, Editor(s)