Ablatherm HIFU for prostate cancer

Description:

• HIFU : Transrectal High Intensity Focused Ultrasound (Ablatherm)
The ABLATHERM HIFU is a medical device piloted by a computer, designed to treat localized prostate cancer using high intensity focused ultrasound (HIFU). The energy is delivered through an endorectal probe. The ultrasound waves travel through the rectal wall and are focused in the prostate. This focusing produces intense heat and provokes the destruction of the tissue inside the targeted zone without damaging surrounding tissues. The treatment (1 to 3 hours) can be performed under spinal anesthesia.

This therapy is now widely available as an alternative therapeutic option for prostate cancer which presents 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.

This treatment is recommended for patients with localized prostate 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 for patients who have local recurrence after external radiotherapy ("salvage" treatment).

The treatment is performed transrectally, generally under spinal anesthesia. A probe is placed in the rectum. This probe emits a beam of high intensity convergent ultrasound. In the point where the ultrasounds are focused (focal point) the sudden and intense absorption of the ultrasound beam creates a sudden elevation of the temperature (from 85 to 100°C) which destroys the cells located in the targeted zone.

In 1989, INSERM unit U281(French National Institute for Health and Medical Research), the Urology service of the Edouard Herriot Hospital Lyon, France and EDAP Technomed joined efforts and initiated a research project in France. This project was to develop an efficient and minimally invasive treatment for localized prostate cancer (stages T1-T2). After ten years of development, the Ablatherm HIFU was CE marked (European approval) and the FDA gave approval for the United States to conduct a clinical study.
Today thousands of patients have been treated in several centers throughout the world.

The Ablatherm is a combination of various components:

• A table for the patient to lie on during the treatment.
• An ultrasound high resolution imaging system, which allows the visualization of the prostate by the surgeon.
• An endorectal probe consisting of an integrated echographic transducer for a real time high resolution imaging and the treatment transducer, which emits the focused ultrasounds. This probe is placed in a latex balloon filled with cooled liquid.
• A computer which controls the robotic arm and aims the shots according to the firing plan established by the surgeon.

Many safety devices are connected to the equipment to guarantee the patient’s security and the optimal effectiveness of the treatment:

• A continuous control of the treatment probe’s position in relation with the rectum wall.
• A detector of patient’s movements.
• A constant control of the rectal temperature.
• A constant control of the power delivered to the patient.

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

   Preparation
The patient is generally hospitalized the day of treatment. He is given an enema for colorectal preparation the night before and two hours before treatment, as well as oral antibiotics.

   Procedure
The treatment is generally performed under spinal anesthesia. The treatment is executed with the patient lying in a right lateral position. Strict immobility is necessary during the treatment, which explains the administration of a sedative.

The treatment is performed transrectally. A probe is placed in the rectum. This probe emits a beam of high intensity convergent ultrasound. In the point where the ultrasounds are focused (focal point) the sudden and intense absorption of the ultrasound beam creates a sudden elevation of the temperature (from 85 to 100°C) which destroys the cells located in the targeted zone.

The targeted prostatic volume is localized with the ultrasound imaging transducer.

High-energy ultrasound waves are focused through the rectal wall to the targeted prostate area.

The targeted zone destroyed by each shot is oval-shaped and measures up to 24 mm in height by less than 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 tumor (400 to 600 shots are generally done to treat the volume previously defined).

The treatment duration varies according to prostate volume (1 to 2 hours). Swelling of the prostate appears immediately after the treatment and compresses the urethra. A temporary urine catheter is inserted. This allows the elimination of urine until the edema recedes (which takes generally from 3 to 8 days depending on the case).

A transurethral resection of the prostate(TURP) is done before  the treatment with HIFU. This is to prevent obstruction to flow after treatment, to reduce the size of the prostate, remove any irregularities, calcifications, which would interfere with Ultrasound imaging. Prior TURP has been shown to improve results and reduce complications with Ablatherm HIFU treatment.

Team:

The South African Ablatherm HIFU team consists of Dr Stephen Eppel Urologist, Mr Sean Parker Application Specialist, Dr Gary Kantor Anaesthetist and several theatre sisters trained in the technology. 

Dr Eppel completed his Urology training at the University of the Witwatersrand in 1986 and thereafter spent approximately 20 years in the United States in both academic and private practice.  He is American Board Certified and Fellowship trained.  Dr Eppel has spent the last 3 years intensively evaluating and using HIFU as a treatment option for prostate cancer.  He has received training and is certified to use both the Ablatherm and Sonoblate devices.  His preference is the Ablatherm because of its longer track record supported by significantly more data as well as the fact that it is a fully robotic and therefore less user-depended treatment.  It is therefore considered safer with more predictable outcomes.

Both Dr Eppel and Mr Parker have spent time in France and Germany training with the Ablatherm device.  International expert, Professor Stefan Thuroff  supervised their first treatments in Cape Town. All patients treated so far have done well, leaving the hospital the same day or 1 day after and have had no major complications. There are approximately a 148 Ablatherm treatment sites across the world to date, with more than 16,000 patients treated over the last 11 years. Although the FDA has not yet approved HIFU for general use in the USA as it is undergoing phase three clinical trials, there is Regulatory Body approval in Canada, Central America, the United Kingdom, Europe, Japan and Australia.  More than 20 peer reviewed publications and more than a 100 abstracts on Ablatherm HIFU have been presented at international scientific meetings. 

The treatment consists of an initial transurethral resection of the prostate (TURP) followed by the HIFU treatment about 6 weeks later.  The reasons for TURP are as follows:  to prevent the destroyed prostatic tissue causing obstruction to urinary flow, to decrease the size of the prostate and remove any irregularities(prostate middle lobe) or calcifications, which would interfere with ultrasound imaging.  It has also been shown that the side effects are lower, and the results generally better with TURP being performed prior to HIFU, especially with large glands. However, patients with very small prostates need not undergo TURP prior to HIFU. The HIFU treatment takes place at The Broad Road Clinic in Cape Town. It is performed under combination spinal/epidural anaesthesia, lasts between 2 – 3 hours, is very well tolerated and the patient leaves the facility the same day. A catheter drains the bladder for about 7 days, after which the patient resumes normal activity.