What is Cryotherapy?
Cryotherapy or cryoblation for prostate cancer is the controlled freezing of the prostate gland. The freezing destroys cancer cells. Cryotherapy is done under general or spinal anesthesia. The prostate is imaged and measured. An aiming program projects images on a screen.
Special needles called "cryoprobes" are placed in the prostate under the skin, guided by ultrasound. Argon gas creates an "ice ball" that kills cells in the area. Monitoring lowers the risk of injury to the nearby normal tissues. The procedure is usually done in 2 hours.
Cryotherapy is not cancer specific. The treatment will affect all cells in the targeted area. Freezing can damage molecular, cellular and whole tissue. Cryotherapy causes immediate cell death, delayed death from lack of oxygen, and programmed cell death. The immune system may be able to better fight cancer once cancer cells are killed.
The cells are not the only structures damaged during freezing. Connective tissue and the smallest blood vessels (capillaries) are damaged. They will then lose blood supply. That is also believed to kill the cancer cells.
Each type of cryotherapy has different probes and placement. All aim to freeze the prostate, tumor(s) and nearby tissue-except the urethral area. A urethral warming catheter keeps the urethra warm. It is kept active for about 20 minutes after the final thaw cycle. This prevents the urethra from freezing. Small temperature probes are placed in and around the prostate. They monitor the rectal wall and urinary sphincter temperatures. This helps lower side effects like incontinence and rectal fistula.
Freezing starts at the front of the prostate by activating the probes. Then the middle and finally the back parts are frozen. This allows monitoring by ultrasound and sculpting of the ice balls. The health care provider knows when to stop freezing.
There are usually two freezing cycles. Between them, the prostate is allowed to thaw passively or actively using helium or argon gas. If the prostate is longer than the probe, a pullback move freezes the top of the prostate. Double freezing is performed again.
After the final thaw, a catheter (a drainage tube in the bladder through the lower belly) is inserted. Your health care provider will remove it in a few days, when you are able to urinate.
A PSA test is usually done at three months. A biopsy may be done later. This will check to make sure your prostate was destroyed and all cancer cells are dead. This is done especially if the PSA level keeps climbing. Once the PSA level is stable, the PSA may be checked every 6 months or yearly. If the PSA level keeps changing, your health care provider will monitor it closely.
What Are The Benefits, Risks and Side Effects of Cryotherapy?
You may be pleasantly surprised to find there is little to no pain after treatment. Recovery is usually in the first week. Cryotherapy offers:
- A minimally invasive, outpatient procedure
- Favorable success rate
- Low toxicity profile (complication rate)
- High quality of life
- A short recovery
- No blood transfusions
- Minimal anesthesia
- Effective use for high grade cancers
- Good margins by extending the ice beyond the confines of the prostate
- Trauma to prostate cancer that resists radiation, hormones or chemotherapy
- Primary treatment or treatment for those who have failed radiation treatment
- The possibility of repeating the procedure if the first treatment did not completely kill the cancer
- The choice to use radiation therapy, radical prostatectomy, or hormonal therapy if the procedure fails
- Less than half the cost of the traditional treatment
The biggest risk of treatment is a fistula. A fistula is a channel between the urethra and the rectum. This may cause diarrhea from urine in the rectum. It may cause sever infection from bacteria in the bladder. This is rarely seen with today's technology. A recent study of over 1000 patients in the COLD registry (Cryo On Line Database) showed a rectal fistula rate of only 0.4%.
There is a high risk of erectile dysfunction when freezing the entire prostate Your health care provider will have ways to better preserve erections if you are a candidate for a nerve-preserving procedure.
When you leave the hospital you will have a catheter in place for drainage. This treatment procedure will cause your prostate to swell. The catheter is removed when the swelling goes down.
You must be able to urinate on your own. The catheter may need to be reinserted if there is still swelling. Most men can urinate in about 5 to 15 days. But some may take longer. You may need oral antibiotics or other medicines to help urination or reduce catheter irritation. Your health care provider decides this.
Other rare side effects include long-term incontinence and urinary retention. Permanent, sever incontinence is rare (about 1%). Abscess and permanent numbness of the penis are also rare. Scrotal swelling, passage of flecks of tissue, pain or burning when urinating, and increased urinary frequency or urgency are other rare side effects. The most common symptoms are from the catheter: urinary urgency and blood in the urine.
The new technology has fewer side effects. A new urethral warming device has lowered urethral complications. Better spacing of the probes makes the procedure safer and effective. Improved ultrasound monitoring of the freezing and temperature can help your doctor control the size and shape of the ice balls.
Who Are Good Candidates for Cryotherapy?
This is a good treatment if you have just had radiation therapy and your prostate cancer comes back. This is also good if you have organ-confined prostate cancer or little spread beyond the prostate (up to T3a). you may receive this treatment if you are having prostate cancer treatment for the first time. You may also get this treatment if your cancer returned after radiation treatment (external beam or brachytherapy). Cryotherapy is effective removing cancers of any Gleason grade.
Smaller needles may be able to destroy the area of the prostate with cancer rather than the entire prostate. This new form of cryotherapy may change the way prostate cancer is treated in the future.