This is a medical technology that is in its early stages and is used worldwide to treat many conditions. The mechanism of this technique is similar to focusing light using optical lenses. In High intensity focused ultrasound uses an acoustic lens (a lens that focuses sound waves) and concentrate the waves on the target tissue. As the sound wave travels through the body tissues there will be no effects but the focus point where the sound waves converge will have thermal and mechanical effects.
This is used in prostate cancer treatment, uterine fibrosis, neurological disorders, other types of cancers, and cosmetic medicine. In the treatment of prostate cancer, the highly focused sound beam is guided using an MRI (magnetic resonant image). The sound waves used in HIFU is having lower frequencies than diagnostic ultra sounds but significantly higher energies.
In the year 2015, United States Food and Drug Administration (FDA) approved the use of HIFU to treat prostate cancer in men. “For men with conditions like prostate cancer, the option of a non-invasive procedure that can selectively target and treat diseased tissue is very appealing,” explained Neal Kassell, MD, chairman of the Focused Ultrasound Foundation, in a statement. “American men have been traveling overseas for focused ultrasound treatment for prostate diseases for years, and we are pleased that they will now have access to this innovative treatment at leading centers in the United States.”
Before the procedure:
If you are diagnosed with prostate cancer you will be treated medically first. If you decide to go for HIFU, first you will be screened, then you will have to do an MRI scan to get a detailed look on your prostate gland. Sometimes a prostate biopsy will also need to be done to detect the type of cancer and the involvement of the prostate. Based on these results your surgeon will determine exactly where the high-intensity ultrasound is to be focused.
Source: HIFU. (2017). Retrieved from http://hitconsultant.net/2015/12/04/fda-clears-non-invasive-hifu-treatment-for-prostate-cancer/
During the procedure:
On the morning of the procedure, you will be given an enema (liquid entered into your rectum to induce bowel movement) to empty your bowels and you will have to fast for about 6 hours prior to HIFU.
During the procedure, you will be unconscious and you will be given a general anesthetic. (Spinal anesthesia is given to numb you below your lower back if you have any contraindications for general anesthesia).
During your treatment, you will either lie on your back with your legs apart or on your side with your knees bought up towards your chest. Then a catheter is inserted into your urinary tract to drain urine out of your bladder. The surgeon will enter a probe through your rectum which emits a beam of high-intensity ultrasound energy that will travel through your tissues into the prostate targeting small area at a time. The area of the focus of the beam will be roughly the size of a grain of rice. The probe sound waves also use ultrasounds to create an image of the prostate for the surgeon to guide the high-intensity ultrasound beam. The highly focused beam, therefore, targets cancer cells and spares healthy cells.
This procedure usually lasts 1-3 hours. If the treatment is done as a whole HIFU, where the entire prostate is treated it can take about 3 hours. Focal HIFU where only a part of the prostate is treated takes only about 2 hours. This is done as an outpatient procedure and you can go home after this is done.
After the treatment and possible side effects:
Following the treatment, your fitness will be assessed to go home and you can go home on the same day. You will be given pain killers for pain and possible discomfort as well as antibiotics to prevent the risk of possible urinary tract infections. The treatment can cause swelling in your prostate and it will cause difficulties in urination, therefore, a urinary catheter will be placed for you to pass urine for about a week. (You will be educated on how to look after the catheter and a date will be given for the removal of the catheter)
As with every treatment you can have side effects they can be short term or long term. Short term side effects include the blood and tissue particles in urine, erectile dysfunction, urinary tract infections, difficulty in urination and emptying the bladder.
Long term side effects are associated with the sexual function, even though erectile function may increase with time some may not, you will be able to climax after HIFU but the fertility may be affected. Sometimes you may have long term urinary problems such as incontinence (leaking of urine), Increase the urge and frequency of urination. Very rarely in less than 1% of the cases, you may get a rectal fistula a hole that connects the urinary tract and the rectum after HIFU.
Advantages of HIFU:
- It is an outpatient procedure.
- Short recovery time (1-2 weeks)
- This is not an invasive procedure involving surgery and the surgical complications are avoided.
- If cancer reoccurs HFU can be repeated. This is not possible with all the cancer treatment. Even other treatment options such as chemotherapy and surgery are possible if cancer comes back.
Disadvantages of HIFU:
- Since the FDA approval has been given 2015 there are no long term studies that have been done on its efficacy, comparisons with other treatment options, risks and side effects over a long period of time (for over ten years).
- The side effects mentioned above are possible.
You will have to follow up with your GP or the initial surgeon who did the HIFU to:
- Check how your cancer has responded to treatment
- Deal with any side effects of treatment.
You will have blood tests called prostate specific antigen (PSA test) done every 3-6 months in the first few years to check if the HIFU has worked. Prostate biopsy or an MRI study will also be done to see if the treatment has worked.