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 You are here : Physicians > HIFU - Ablatherm > About Ablatherm > Overview
Ablatherm Device dot This therapy is available as a new therapeutic option for localized prostate cancer which presents the advantages of a non-invasive treatment: precise local treatment in one session, repeatable if necessary low complication rate*, with a short period of hospitalization.

This treatment is recommended for patients with localized cancer (stage T1-T2) who are not candidates for a prostatectomy (because of their age, their general state of being or an associated disease) or patients who want an alternative to surgery. Additionally, this treatment can be used with patients who have local recurrence after external radiotherapy ("salvage" treatment").

The Ablatherm HIFU is approved in Europe, Canada, Russia, Australia and South Korea. An approval process is ongoing in many other countries. The Ablatherm HIFU is not available in the US where a clinical trial is ongoing (for more information on US clinical trial CLICK HERE.)

* Long-term results with HIFU in 140 patients with localized prostate cancer
Blana A (1) , Thuroff S (2) , Murat FJ (3),Walter B (1), Chaussy C (2) and Gelet A (3).
1- Department of Urology, University of Regensburg, St Josef Hospital, Germany.
2- Krankenhaus Munich-Harlaching, Germany.
3- Edouard Herriot Hospital, Urology and Transplantation Department, 69437 Lyon, France
European Association of Urology congress 2007, Berlin
Dot Ablatherm Features
The Ablatherm uses separate crystals for imaging (7.5 MHz) and treatment (3 MHz). Thus, the dependence of image resolution is removed from the equation when ablation is occurring. Imaging probes for prostate applications tend to range from 5.0 MHz to 7.5 MHz with probes creating higher quality images having higher frequencies. The real time 7.5 MHz probe used by the Ablatherm creates a very high quality image throughout the prostate and a 3 MHz treatment probe is the best frequency for treatment. Thus, optimal values are used for both imaging and treatment. Using separate imaging and treatment probes did, however, necessitate the removal of the imaging probe and insertion of a treatment probe prior to the commencement of HIFU. This is no longer an issue with the most recent Ablatherm Integrated Imaging model which has both the imaging and treatment crystals contained within a single probe. This allows not only for optimal operating frequencies for both treatment and imaging but also allows for real time imaging during the procedure.
probe dot The Ablatherm uses separate crystals for imaging (7.5 MHz) and treatment (3 MHz)
Dot Treatment Planning
Ablatherm HIFU allows for the creation of an accurate geometrical ablation volume. Treatments are planned based on the anatomy of the individual patient. Pretreatment ultrasound images are captured and the user defines on them, with computer assistance, the regions to be ablated. The program then controls the ablation probe which treats exactly where the user specifies. The Ablatherm uses three treatment algorithms each designed for specific applications: HIFU as a primary treatment, HIFU following failed radiation therapy and HIFU retreatment. This is critical as the thermal properties of a prostate that has never undergone a treatment is vastly different than one which has. When treating a gland that has been irradiated care must be taken as the dissipation of energy will now be slower due to decreased blood flow throughout the prostate. This is a result of radiation damage to the prostate's blood supply. The same will be true, but to a different extent, for a prostate that has previously been treated with HIFU. The reason this is important is that if not enough time is given for energy to dissipate a build up can occur which could lead to rectal injury and other complications.
Dot Real Time Monitoring
The realtime imaging available with the Ablatherm is used to detect the rectal wall position and compares this position to the one measured during treatment planning. The probe position is automatically adjusted to compensate any difference between these two measurements.
rectal dot Automatic rectal wall detection in real time during treatment. If any micro-movements are detected, the position of the probe is adjusted automatically with the robotic arm.
Dot Ablation Volume Geometry and Transducer Size
Each pulse of a HIFU crystal will induce a discrete and consistent volume of tissue necrosis. The Ablatherm uses a single treatment probe that has a focal point 45 mm from the crystal. The 3.0 MHz probe creates an ablation volume which size is adjustable from 24 mm (anterior to posterior) x 1.7 mm x 1.7 mm (total volume = 36 mm3) down to 19 mm x 1.7mm x 1.7 mm (total volume = 29 mm3). The intent is that a single pulse will result in an ablation that extends the entire anterior to posterior height of the prostate. This strategy has the advantage that only one focus is needed to treat the entire height of the gland.
Dot Safety Features

1. Patient movements

If a patient moves during the procedure the treatment must be stopped immediately and the treatment plan must be re-checked. The strategy used to detect movement with the Ablatherm, relies on an automated infrared detection system to ensure that the patient has not moved. This removes human error from the equation.

2. Patient position

If bubbles are present in the fluid surrounding the treatment crystal or are created during treatment they will rise and end up between the crystal and the prostate. This can compromise the treatment quality (both in terms of ablation and targeting) as air sharply reflects ultrasound. Treatment by the Ablatherm is performed with the patient in a right lateral decubitus position (lying on their right side). This is done as a safety precaution. If there are any bubbles in the fluid surrounding the treatment probe they will rise upwards. With the patient on his side and the treatment aimed laterally bubbles will not end up between the HIFU treatment crystal and the prostate.

a) Ablatherm : patient on his right side : cavitation bubbles doesn't compromise treatment quality

b) other options : patient on his back : cavitation bubbles can compromise treatment quality

 dot bubbles

3. Rectal wall monitoring

During HIFU temperatures increase not only at the zones of ablation created by the deposit of sonographic energy but also throughout and adjacent to the prostate due to thermal conduction. The rectal wall is sensitive to temperature changes, justifying the need for precise rectal monitoring. To maintain acceptable temperatures throughout the rectal wall, Ablatherm use the following strategy:

  1. active cooling of the rectal wall during treatment,
  2. continuous monitoring of the temperature of the rectal wall, and,
  3. continually measuring the distance between the rectal wall and the prostate.

Combined, these measures have reduced the occurrence of rectal fistulas with the Ablatherm to essentially zero. Additionally, the infrared system used by the Ablatherm to monitor patient position will cause the device to shut off instantly if any movement is detected.

 

 
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