HIFU - or High Intensity Focused Ultrasound - is a newer prostate cancer treatment option that is gaining favor with urologists and patients. HIFU treatments have been available in Europe for over 10 years and were approved by Health Canada in 2003. There are 2 types of HIFU devices: Ablatherm and Sonablate. If you are considering treating your prostate cancer with HIFU, then it is important to understand the 2 options available to select the one that is right for you.
Ablatherm vs. Sonablate HIFU devices
There are two medical devices that perform the high intensity ultrasound procedure. One is the Ablatherm device which is manufactured in France. The other is Sonablate, manufactured by a U.S. company. Both devices are used to treat prostate cancer using computer imaging and targeted infrared waves to heat and destroy cancer cells on the prostate.
The devices, while performing a similar function, do have differences:
The imaging is better on the Ablatherm device with dual ultrasound transducers on the probe delivering 7.5 megahertz imaging vs. 4 megahertz single image with the Sonablate.The firing device on the probe is computer controlled on both models to target tumors on the prostate. High precision is necessary to prevent rectal injury and to preserve neurovascular bundle which controls erectile function. The Sonablate technology requires multiple probes to complete the treatment due to short focal length. Each probe head must be manually placed and manipulated, making the procedure very operator dependent. The Ablatherm device is positioned by the physician and then robotically controlled via extremely precise software. The variable lesion height in the probe allows energy to be delivered in a pattern that conforms to the anatomy of the prostate. The energy is delivered to the target within a 1/10thof a millimeter precision.
The onus for safety is on the operator with the Sonablate device. They are required to monitor the safety parameters and adjust the energy output to prevent rectal injury or injury to surrounding tissue. The Ablatherm device will automatically disengage if any of the parameters of the 4 safety features are violated. The Ablatherm device has 4 sensors that monitor rectal wall temperature, rectal wall thickness, distance to target and an external motion detector. The safety features are checked before each discharge of energy and the device will not fire if any of the 4 parameters are violated. There are 600-700 discharges during each treatment, and the safety parameters are checked before each and can disable the device to prevent injury.
Treatment time. Treatment time with the Ablatherm device is generally 2-2.5 hours. With the Sonablate device, treatment can last between 3.5-5 hours, due to the manual requirement of probe changes and small treatment field. However, larger prostates can be treated with the Sonablate device, but frequently require a TURP post treatment or prolonged catheterization.
The overwhelming published literature and clinical results are all Ablatherm based. The only North American clinic that offers the Ablatherm option is Maple Leaf HIFU in Toronto, which also happens to be the first North American clinic to offer HIFU after it was approved by Health Canada. The HIFU option has been available in Europe for over a decade, but HIFU is not yet available in the United States. Patients are generally willing to travel to Toronto or elsewhere to get the procedure, since it is non-surgical and non-invasive, with similar or better success rates to surgery or radiation. There is also less down time and fewer side effects, like incontinence or impotency, making it a better option for younger men (50-80) with prostate cancer. If you are diagnosed with prostate cancer, consider HIFU as an option, and compare Sonablate vs. Ablatherm HIFU devices when doing your prostate cancer treatment options research.
Nancy Stonecutter is a nurse who writes about family and health care. Visit her blog at http://www.nancythenurse.wordpress.com/ for more information.
