Abstract:Two devices are currently available for the treatment of prostate cancer with HIFU: Sonablate® and Ablatherm®. The outcomes achieved for primary-care patient are very promissing with mid- and long-term progression-free survival rates around 70%, negative postoperative prostate biopsies almost 85%, and an excellent morbidity profile. Moreover, HIFU has a considerable potential for local recurrence after radiation failure. Recently, some early experiences on focal therapy suggest that HIFU could be an excellent … Show more
“…Other investigations have demonstrated the capability of highintensity ultrasound energy for treating prostate tissues using transrectal, interstitial or transurethral devices [13][14][15][16][17]. Long-term clinical follow-up of ultrasound-guided transrectal HIFU confirms that this treatment of localised prostate cancer is feasible, and can achieve acceptable local control of disease with the potential for a reduced impact on quality of life [7,8,[18][19][20].…”
Transurethral ultrasound therapy uses real-time magnetic resonance (MR) temperature feedback to enable the 3D control of thermal therapy accurately in a region within the prostate. Previous canine studies showed the feasibility of this method in vivo. The aim of this study was to reduce the procedure time, while maintaining targeting accuracy, by investigating new combinations of treatment parameters. Simulations and validation experiments in gel phantoms were used, with a collection of nine 3D realistic target prostate boundaries obtained from previous preclinical studies, where multi-slice MR images were acquired with the transurethral device in place. Acoustic power and rotation rate were varied based on temperature feedback at the prostate boundary. Maximum acoustic power and rotation rate were optimised interdependently, as a function of prostate radius and transducer operating frequency. The concept of dual frequency transducers was studied, using the fundamental frequency or the third harmonic component depending on the prostate radius. Numerical modelling enabled assessment of the effects of several acoustic parameters on treatment outcomes. The range of treatable prostate radii extended with increasing power, and tended to narrow with decreasing frequency. Reducing the frequency from 8 MHz to 4 MHz or increasing the surface acoustic power from 10 to 20 W/cm(2) led to treatment times shorter by up to 50% under appropriate conditions. A dual frequency configuration of 4/12 MHz with 20 W/cm(2) ultrasound intensity exposure can treat entire prostates up to 40 cm(3) in volume within 30 min. The interdependence between power and frequency may, however, require integrating multi-parametric functions in the controller for future optimisations.
“…Other investigations have demonstrated the capability of highintensity ultrasound energy for treating prostate tissues using transrectal, interstitial or transurethral devices [13][14][15][16][17]. Long-term clinical follow-up of ultrasound-guided transrectal HIFU confirms that this treatment of localised prostate cancer is feasible, and can achieve acceptable local control of disease with the potential for a reduced impact on quality of life [7,8,[18][19][20].…”
Transurethral ultrasound therapy uses real-time magnetic resonance (MR) temperature feedback to enable the 3D control of thermal therapy accurately in a region within the prostate. Previous canine studies showed the feasibility of this method in vivo. The aim of this study was to reduce the procedure time, while maintaining targeting accuracy, by investigating new combinations of treatment parameters. Simulations and validation experiments in gel phantoms were used, with a collection of nine 3D realistic target prostate boundaries obtained from previous preclinical studies, where multi-slice MR images were acquired with the transurethral device in place. Acoustic power and rotation rate were varied based on temperature feedback at the prostate boundary. Maximum acoustic power and rotation rate were optimised interdependently, as a function of prostate radius and transducer operating frequency. The concept of dual frequency transducers was studied, using the fundamental frequency or the third harmonic component depending on the prostate radius. Numerical modelling enabled assessment of the effects of several acoustic parameters on treatment outcomes. The range of treatable prostate radii extended with increasing power, and tended to narrow with decreasing frequency. Reducing the frequency from 8 MHz to 4 MHz or increasing the surface acoustic power from 10 to 20 W/cm(2) led to treatment times shorter by up to 50% under appropriate conditions. A dual frequency configuration of 4/12 MHz with 20 W/cm(2) ultrasound intensity exposure can treat entire prostates up to 40 cm(3) in volume within 30 min. The interdependence between power and frequency may, however, require integrating multi-parametric functions in the controller for future optimisations.
“…The documented complications of HIFU, according to the European Multicentre Study (Thuroff et al 2003), include impotence (of patients potent preoperatively, 35%), mild-moderate incontinence (14%), UTIs (13.8%), prolonged retention (9%), urethral stenosis (3.6%), severe incontinence (1.5%) and rarely rectourethral fistula (1.2%) [2,5,][6]. Our patient experienced several of these complications including urinary retention from prostatic slough, urethral stricture, severe stress incontinence and multiple UTIs.…”
Section: Discussionmentioning
confidence: 99%
“…Although the American Urologic Association guidelines do not formally recommend HIFU for the treatment of prostate cancer, many patients have been treated with this modality, and identifying adverse effects is important. The principle mechanism of HIFU involves the generation of ultrasound waves directed transrectally to the prostatic bed, resulting in focal destruction of prostatic tissue through coagulative necrosis [1,2]. Known complications from HIFU include urinary retention, urethral stenosis, impotence, stress incontinence, urinary tract infections (UTIs), and rarely, rectourethral or rectovesicular fistula [3,4,5].…”
High-intensity focused ultrasound can be used for the primary treatment of prostate cancer and biochemical recurrence after radical prostatectomy or radiation. Complications of high-intensity focused ultrasound include urinary retention, urethral stenosis, stress incontinence, urinary tract infections, dysuria, impotence, and rarely, rectourethral or rectovesicular fistula. We describe a patient presenting with urinary retention, urinary tract infections and intermittent stress incontinence, later found to be associated with pubic bone osteomyelitis stemming from a prostatopubic fistula.
“…High intensity focused ultrasound (HIFU) is being developed for use in the clinic, with the aim of enabling thermal ablation of tumours [1][2][3][4][5], drug delivery [6][7][8], and a number of other applications. As its use becomes more widespread, there is an ever increasing need to standardise the way in which the delivery of HIFU therapy is described and reported.…”
As the use of HIFU in the clinic becomes more widespread there is an ever increasing need to standardise quality assurance protocols, an important step in facilitating the wider acceptance of HIFU as a therapeutic modality. This article reviews pertinent aspects of HIFU treatment delivery, encompassing the closely related aspects of quality assurance and calibration. Particular attention is given to the description and characterisation of relevant acoustic field parameters and the measurement of acoustic power. Where appropriate, recommendations are made.
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