With anything new, there are always questions. The same holds true for HIFU for prostate cancer. In addition to questions being common about what the procedure is and how it works, some of the most common questions about HIFU come from the fact that it was available outside the United States for nearly 10 years before it was approved by the FDA for prostate ablation in the US.
This article addresses some of those common questions about HIFU and hopefully will answer questions that you may asking yourself right now as you explore prostate cancer treatment options.
What is HIFU?
HIFU, which stands for high intensity focused ultrasound, is the focusing of sound waves to create heat at a specific point; this is called the focal point. This heat effectively destroys the targeted tissue. HIFU was cleared by the FDA for prostate ablation in October 2015 although it has been available outside the United States for more than 10 years for the treatment of localized prostate cancer and benign prostatic hyperplasia (BPH) or prostate enlargement.
What is the Sonablate®?
The Sonablate® is a non-invasive medical device manufactured by SonaCare Medical, which uses HIFU to ablate tissue which trained physicians can use for treating prostate cancer and BPH. The Sonablate® uses a single transducer to obtain real-time images of the prostate during treatment and provides treatment in zones from top to bottom and from side to side. Sonablate® software allows the surgeon to customize each of the treatment zones to safely ablate the entire gland.
What are the outcomes of the Sonablate HIFU treatment?
An international study published by Toyaki Uchida, MD (Japan) reported that 94% of patients (low risk) were disease-free after four years. Additionally, 92% of men treated with HIFU had a PSA of .2ng/ML or lower 3 months after HIFU as reported in a study by Dr. Mark Emberton of London.
Does HIFU only treat the cancerous cells?
Sonablate® HIFU will ablate any tissue that the physician targets with the device during treatment planning. After the physician reviews your diagnosis, he or she will make a recommendation on the best course of treatment. This recommendation, based on your pathology report, will include how much of the prostate should be treated. In most cases, the entire prostate will be targeted, which would include the tumor as well as any other tissue in the prostate. Think of it as having the prostate removed, without a single incision. However, some physicians, who work with advanced, MRI- guided imaging for diagnosis, can determine the exact location of the tumor in the prostate and may use HIFU to only treat the tumor leaving other tissue in the prostate intact; this is referred to as focal therapy.
What is the history of HIFU and how long has it been around?
HIFU research began as far back as the 1950s at Indiana University. However, the first human prostate cancer study was conducted in 1994 by Dr. Marberger and Dr. Madersbacher at the University of Vienna in Austria using the Sonablate® 200, treating 29 human prostates in vivo shortly before performing a radical prostatectomy. The goal was to see if the energy delivered was enough to destroy the desired tissue. The study found that treatment could be performed safely and could be repeated.
In 1995, a different study, done at Indiana University showed that the entire prostate could be treated without damaging the prostate capsule or the rectal wall. In 1999, Dr. Toyaki Uchida began treating patients using the Sonablate in Japan. The device received approval for use in Europe with the CE Mark in 2001 and in 2004, treatment became available at hospital and treatment centers in Mexico, Costa Rica, South Africa and the Caribbean. Health Canada approved the Sonablate 500 in June 2005 and the first Sonablate HIFU procedures were performed in Toronto in March 2006.
Currently, there are approximately 300 physicians using the Sonablate worldwide and over 15,000 total procedures have been completed. SonaCare Medical is the manufacturer of the Sonablate and received cleared from the FDA for prostate cancer ablation in October 2015.
How does Sonablate HIFU compare to HIFU with the Ablatherm?
The Sonablate device allows for a more precise and customized treatment than the Ablatherm. Sonablate software allows for smaller treatment zones and adjustable energy delivery, which allow for focal treatments and less risk in damaging important structures such as the urinary sphincter and nerves that are important for erections. Additionally, it is possible to treat larger prostate glands with the Sonablate. Read a detailed comparison of the devices here.
Which features are unique to the Sonablate that are focused on patient safety?
The Sonablate is a highly sophisticated device that includes numerous features for patient safety including:
- Neurovascular bundle detection helps the physician to avoid causing harm to sensitive structures surrounding the prostate, like neurovascular bundles. The ability to avoid a neurovascular bundle can have a significant effect on maintaining erectile function and help to preserve a patient’s quality of life.
- Rectal wall monitoring helps determine the temperature of and proximity to the rectal wall. This helps the physician protect the rectal wall tissue during therapy.
- The active cooling system circulates chilled water through the probe during the procedure while monitoring temperature, which helps the physician protect the rectal wall tissue from heat generated during thermal ablation.
- Real-time imaging allows the physician to view and compare the original image to the real-time image being treated, for visual ablation confirmation.
- MRI/Ultrasound fusion integration software allows the physician to merge MRI images into the Sonablate planning software, fusing them with the real-time ultrasound images. The physician can then determine a more precise ablation plan based on the fusion of these two key datasets.
- TCM or Tissue Change Monitoring is a color display that (during tissue ablation) gives the physician enhanced feedback about the change in tissue at each point of HIFU delivery.
How do I know if I qualify for HIFU?
While only a physician can determine if you qualify for HIFU or not, typically men with a prostate gland of less than 40 grams with localized prostate cancer (tumor has not spread outside of the prostate gland) may be candidates for HIFU. The other information that physicians usually look at to determine if you qualify for HIFU is a PSA of 20 or less and a Gleason score of 7 or less. It is best to talk with a HIFU nurse or doctor to determine if you might qualify for HIFU.
How does HIFU compare to traditional treatments for prostate cancer, including surgery and radiation?
Studies show that HIFU has rates of efficacy similar to other treatments for prostate cancer but with less risk for side effects such as incontinence and erectile dysfunction. HIFU also does not exclude you from having any other treatments, should you have a recurrence of prostate cancer, as other treatments such as surgery and radiation will.
Is HIFU a type of radiation, like brachytherapy?
No, HIFU is completely radiation free. Unlike radiation, HIFU is a clean, or non-ionizing, energy source. This means that it can be repeated as necessary, and will not prevent a patient from pursuing any other treatment options after HIFU. During brachytherapy, radioactive seeds are placed inside the prostate and remain in the prostate after the procedure is complete. Often times, these seeds will migrate to other organs, which can cause additional issues for patients.
How long does the HIFU procedure take?
The length of the procedure depends on the size of the prostate gland. Larger glands will take longer to treat completely. A way to estimate time is 1 hour for every 10 grams of tissue to be treated. That works out to an average of 1.5- 4 hours.
What happens to the urethra during HIFU? Since it runs through the center of the prostate, is it destroyed during the procedure?
During HIFU, the entire prostate is ablated, including the prostatic urethra. However, the urethra is derived from a different type of tissue (bladder squamous-type epithelium) rather than prostatic tissue (glandular, fibrotic and muscular). While the urethra is an important anatomical structure, the sphincter and bladder neck are more important to maintaining the urinary function.
Is there pain with HIFU? What should I expect?
During HIFU, patients are given anesthesia to minimize any movement during the procedure and to make the patient as comfortable as possible. There should be no pain associated with the procedure although patients may experience various levels of discomfort afterward.
What type of anesthesia is used for the HIFU treatment?
General anesthesia is the preferred anesthesia during HIFU procedures. It is very important that you and your prostate remain still for the duration of the procedure, and general anesthesia assures that this happens.
Still have questions? Find even more frequently asked questions here or click here to schedule a call with a HIFU nurse today.
1Five years experience of transrectal high-intensity focused ultrasound using the Sonablate device in the treatment of localized prostate cancer. Toyoaki Uchida, et al. Dept. of Urology University of Tokai Hachioji Hospital. International Journal of Urology 2006.
2 Toyaki U., Shiro B., Akira I., et al., Transrectal high-intensity focused ultrasound in the treatment of localized prostate cancer: A multicenter study.Acta Urol. Jpn. Vol. 51, No. 10, 2005.