Ultrasound imaging, or
sonography, is medical procedure that uses low frequency sound waves to map out the body’s organ systems by using sound. Think
of it as a kind of “bio sonar,” where broad sound waves bounce off organs
instead of ships and provide much clearer images. Despite the similarity in
name, high-intensity focused ultrasound works by using focused beams of high
frequency radio waves as a method to eliminate cancerous or otherwise diseased
soft tissues. They are often used together to map a route and provide guidance
for HIFU targeting.
How is HIFU used?
HIFU is classified as a type of
hyperthermia therapy, a type of medical treatment that exposes body tissue to
higher temperatures to kill cancerous cells. HIFU is essentially identical to
radiofrequency ablation, a procedure that uses heat to close problematic veins
such as varicose veins, though it treats a wider spectrum of disease. It is a
non-invasive procedure used to address uterine fibroids and multiple types of
cancer including:
- Renal cancer
- Liver cancer
- Pancreatic cancer
- Bladder cancer
For prostate cancer, a rectal
probe is used (as high-frequency radio waves cannot pass though solid objects
or gases like air) where the sound waves are then focused into prostate to kill
the tumor. In some cases, the entire prostate and prostatic urethra are
collapsed in the process, however the urethra regenerates due to having
epithelial cells. Historically speaking, the earliest usage of HIFU has its
roots in treating prostate cancer.
What are the benefits of HIFU?
Since
HIFU uses focused energy, it allows doctors to pinpoint and destroy specific
tumors or parts of large tumors with the help of ultrasound imaging.
Once a pathway to the tumor is
determined, sonographers target diseased tissue and destroy it with
highly-focused ultrasound energy. Typically, this type of procedure is done
with machines capable of generating high thermal energy, where the sound waves
are emitted directly into the targeted tissues. This raises the temperature of
the affected organ to up to 85 degrees Celsius. Practitioners actively avoid
going above that threshold to prevent any damage to surrounding tissues due to
liquid boiling.
Unlike chemotherapy which uses a
mixture of debilitating chemicals to treat cancer intravenously, HIFU does not
have to run through the body extensively and will not render patients with
nausea or hair loss. It offers patients fast pain relief as well.
Because it is non-surgical, it is
an outpatient procedure (usually completed in one to three hours) and allows
patients to return to their normal routine immediately. As a specialist
treatment option, patients will need a referral from their general physician; it
is an alternative to those who have exhausted other techniques.
What are the risks?
The risks are minimal, though like
any medical operation, it is not devoid of its limitations and risks. Scar
tissue is problematic for this procedure because its density hinders the
pathways for the treatment to take effect in the affected area. HIFU is most
effective on single tumors (or parts of larger tumors), so patients with
metastasized cancer must seek other treatments. Alternatively, HIFU cannot
treat brain or lung cancers as it cannot penetrate solid bone or air.
Though rare, it can cause skin
burns and collateral tissue damage due to the usage of high-frequency radio
waves. This is because the body absorbs higher frequency waves more readily
than it does with those on the lower end of the electromagnetic spectrum. Since
the skin is the first to come into contact with the concentrated radiation, it
is the first to take the intensity of heat.
To find urologists in your area for HIFU
treatment, consult our directory to find a
doctor near you.