title: Time-dependent change of blood flow in the prostate treated with high-intensity focused ultrasound.
abstract: Avascular areas on contrast-enhanced magnetic resonance imaging have been considered to be areas of localized prostate cancer successfully treated by high-intensity focused ultrasound. However, the optimal timing of magnetic resonance imaging has not been discussed. The thermal effect of high-intensity focused ultrasound is degraded by regional prostatic blood flow. Conversely, the mechanical effect of high-intensity focused ultrasound (cavitation) is not affected by blood flow, and can induce vessel damage. In this series, the longitudinal change of blood flow on contrast-enhanced magnetic resonance imaging was observed from postoperative day 1 to postoperative day 14 in 10 patients treated with high-intensity focused ultrasound. The median rates of increase in the non-enhanced volume of the whole gland, transition zone and peripheral zone from postoperative day 1 to postoperative day 14 were 36%, 39%, and 34%, respectively. In another pathological analysis of the prostate tissue of 17 patients immediately after high-intensity focused ultrasound without neoadjuvant hormonal therapy, we observed diffuse coagulative degeneration and partial non-coagulative prostate tissue around arteries with vascular endothelial cell detachment. These observations on contrast-enhanced magnetic resonance imaging support a time-dependent change of the blood flow in the prostate treated with high-intensity focused ultrasound. Additionally, our pathological findings support the longitudinal changes of these magnetic resonance imaging findings. Further large-scale studies will investigate the most appropriate timing of contrast-enhanced magnetic resonance imaging for evaluation of the effectiveness of high-intensity focused ultrasound for localized prostate cancer.
authors: Department of Urology, Tokai University Hachioji Hospital, Hachioji, Tokyo.
authors: Sunao
authors: S
authors: Shoji
authors: Akiko
authors: A
authors: Tonooka
authors: Akio
authors: A
authors: Hashimoto
authors: Masahiko
authors: M
authors: Nakamoto
authors: Tetsuro
authors: T
authors: Tomonaga
authors: Mayura
authors: M
authors: Nakano
authors: Haruhiro
authors: H
authors: Sato
authors: Toshiro
authors: T
authors: Terachi
authors: Junki
authors: J
authors: Koike
authors: Toyoaki
authors: T
authors: Uchida
mesh_terms: D057086:High-Intensity Focused Ultrasound Ablation; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D011471:Prostatic Neoplasms / Q000098:blood supply* / Q000000981:diagnostic imaging*; D012039:Regional Blood Flow; D012189:Retrospective Studies; D013997:Time Factors; D014463:Ultrasonography
keywords: blood flow; high-intensity focused ultrasound; magnetic resonance imaging; pathology; prostate cancer