HIFU Treatment with Ablatherm®

General Description

This therapy is available as a therapeutic option and has the advantages of a non-invasive treatment, precise local treatment in one session, repeatable if necessary with a short period of hospitalization and a low complication rate. Unlike some other minimally invasive treatments other options are still open after HIFU therapy, if needed.

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 condition or a concomitant disease) and patients who want an alternative to radical surgery.

Additionally, this treatment can be used for patients who have local recurrence after external radiotherapy ( “salvage” treatment).

The treatment is performed transrectally under general or spinal anesthesia. A probe is placed in the rectum. This probe emits a beam of high intensity focused ultrasound. At the point where the ultrasound is focused (focal point) the sudden and intense absorption of the ultrasound beam creates a sudden temperature increase (85 to 100 °C) which destroys the cells in the targeted zone.

The targeted prostatic volume is localised with the biplanar ultrasound imaging probe.	High-energy ultrasound waves are focused through the rectal wall to the targeted prostate area.

The targeted zone destroyed by each shot is shaped like a grain of rice and measures 19 to 24 mm in height by 2 mm in diameter. By repeating the shots, and moving the focal point between each shot, it is possible to destroy a volume that includes the whole prostate.

 

History

In 1989, INSERM unit U556 (National Institute for Health and Medical Research), The Urology Department of the Edouard Herriot Hospital (Lyon, France) and EDAP united their efforts and initiated a research project. This project was to develop an efficient and minimally invasive treatment for localized prostate cancer.

After ten years of development, the Ablatherm® was CE marked in 2000 (market approval for Europe). By July 2005, more than 7500 patients have been treated in several European centres.

It was NICE approved (National Institute for Clinical Excellence) in summer of 2005 for the treatment of localised prostate cancer in the UK.

 

Equipment

The Ablatherm® device is a combination of various components:

• A specially designed bed for the patient to lie on during the treatment.
• An ultrasound generator.
• An integrated ultrasound imaging system, which allows the visualization of the prostate by the surgeon.
• An endorectal head consisting of the imaging probe and the treatment transducer which emits the focused ultrasound. These two elements are placed in a latex balloon filled with a cooled liquid.
• A computer which controls and aims the shots according to the treatment plan established by the surgeon.

Numerous safety features are integrated into the equipment to guarantee the patient safety and optimal effectiveness of treatment:

• A continuous control of the treatment probe’s position in relation to the rectal wall.
• A patient movement detector.
• A cooling system, providing constant control of rectal temperature.

These systems stop the shots automatically if an abnormality is detected during the procedure (displacement of the prostate and/or of the patient), thus guaranteeing the treatment safety.

 

Treatment

Preparation

The patient is admitted to hospital the evening before or the day of treatment and given an enema for colorectal preparation.

Procedure

The treatment is generally performed under general or spinal anesthesia. The treatment is executed with the patient lying on the right side.

The physician introduces the probe in the patient’s rectum after coating the probe with gel and filling the latex balloon with anti-cavitation coupling liquid, which keeps a constant temperature in the rectal wall during treatment. The surgeon locates the limits of the prostate and defines the zone to be treated on the control screen. The treatment can then start (400 to 600 shots are generally given to treat the whole prostate).

The treatment lasts for 1 to 3 hours depending on the prostate volume. The prostate swells after treatment and compresses the urethra so a catheter is usually necessary for 3 to 8 days depending on each patient.

To reduce the length of post treatment catheterisation it is often useful to clear a small amount of prostate to widen the channel through which urine is passed. This is performed at the same time as the HIFU under the same anaesthetic and avoids unnecessary difficulty passing urine on discharge. It is achieved by a telescope passed through the penis and involves no incisions or additional discomfort.

In patients with a very large prostate gland it is sometimes necessary to shrink the prostate with hormone treatment for some months prior to treatment as occurs with radiotherapy.