Home » Patient Care & Information » Smilow Comprehrensive Prostate Cancer Center

Minimally Invasive Ablative Treatment for Prostate Cancer at the Smilow Center

Below you will find answers to frequently asked questions about minimally invasive therapies for prostate cancer.

What minimally invasive ablative options exist for treating prostate cancer? Which of these are currently available in the US?

Minimally invasive ablative therapies for prostate cancer destroy cancerous tissue within the body using intense heat, cold or light energy rather than removing or irradiating the gland. There is increasing interest in applying ablative technology to treating prostate cancer in order to minimize complications of treatment. Smilow Center surgeons offer an array of minimally invasive ablation options and are among the most experienced in the world with these approaches for the treatment of prostate cancer.

Cryotherapy

Cryotherapy involves controlled freezing of prostate tissue using ultrasound guidance. Approved in the US since 1989, cryotherapy has evolved technologically over the past decade and is now considered an effective option for localized prostate cancer. Today, multiple small freezing probes are inserted into the prostate in order to more precisely freeze and ablate the gland (Babaian RJ et al. J. Urol. 180:1993-2004 (2008)).

Cryotherapy is the only minimally invasive ablative therapy currently available outside of a clinical trial in the US. The Smilow Center is recognized as a center of excellence for prostatic cryotherapy. Smilow Center surgeons have successfully offered cryotherapy for over 10 years and have trained hundreds of urologists in this procedure. At the Smilow Center, cryotherapy is considered an effective alternative to radiation therapy for the treatment of localized prostate cancer.

HIFU

HIFU (high-intensity focused ultrasound) is truly a noninvasive treatment that uses precision-focused ultrasound waves to create very high temperatures in the prostate, resulting in ablation or destruction of the prostate. The probes that generate the ultrasound waves are inserted into the rectum rather than directly into the prostate.

Although HIFU has been widely used in Europe and Asia for over 10 years, it is not yet approved by the US Food and Drug Administration (FDA). Therefore, until this new technology is approved by the FDA, the only way to receive HIFU treatment in the US is by participating in a clinical trial. Two different devices (the Sonablate 500 and the Ablatherm) are currently being studied in several clinical trials. Smilow Center surgeons are currently participating in a Phase 3 clinical trial evaluating the effectiveness of the Sonablate 500 in men who have recurrent prostate cancer after initial treatment with external beam radiation therapy. The Smilow Center will also participate in planned clinical trials of the Sonablate 500 for total gland and focal ablation in men with localized prostate cancer.

Photodynamic therapy

Photodynamic therapy is a promising new technology in which prostate tissue can be destroyed directly by light energy. A drug that is sensitive to light (called a photosensitizer) is injected into the bloodstream. Depending upon the type of photosensitizer, it may be absorbed all cells in the body or remain only in the bloodstream. The photosensitizer is excited and causes tissue destruction when exposed to a particular wavelength of light.

Until recently, photodynamic therapy was not embraced by the urology community because it was a very cumbersome procedure for the urologist and the patient. The old photosensitizers were taken up by both normal and cancerous tissue. About 24 to 72 hours after injection of the photosensitizer, the prostate was exposed to light through fibers inserted into the prostate. The photosensitizer absorbed the light and produced a form of oxygen that destroyed both the normal and cancerous prostate tissue. Because the photosensitizer took weeks to clear from the body, men were restricted from sunlight exposure for several weeks.

A novel and more advanced type of photodynamic therapy called vascular-targeted photodynamic therapy has been developed as part of a collaborative venture between Steba Biotech and the Weizmann Institute in Israel. The photosensitizing agent WST-11 is injected intravenously and remains trapped in the blood vessels. Immediately after injecting the photosensitizer, multiple small probes generating a specific wavelength of light are inserted into the region of the prostate where cancer is known to exist. When the region of the prostate containing the tumor is exposed to light, the blood vessels feeding the tumor are destroyed. Since this novel photosensitizer is cleared from the blood stream within 1 hour, there are no restrictions as far as exposure to sunlight after the procedure. (Lepor H, Rev. Urol. 10(4): 254-261 (2008)). Smilow Center oncologic surgeons are currently one of five centers in the United States investigating vascular-targeted photodynamic therapy in a Phase 1 clinical trial.

Laser ablation of the prostate

Lasers have been used to ablate benign prostatic tissue for decades as a substitute to the surgical resection of the prostate (transurethral prostatectomy). Lasers are now being coupled with image-guided technology to ablate prostate cancer. The Smilow Center is one of the first centers in the country to pilot investigations of the Visualase system, a novel laser technology applied for the targeted treatment of prostate cancer.

What are the potential advantages and disadvantages for these minimally invasive ablative therapies?

Minimally invasive ablative therapies offer the possibility of destroying all or part of the prostate gland while minimizing the risks of post-treatment urinary incontinence and erectile dysfunction. All of the ablative therapies can be performed on an outpatient basis, do not require major incisions and offer rapid recovery. Ablative therapies are unique in that they can be repeated if recurrent or residual cancer is found in the prostate in the years after treatment. This is not the case with radiation therapy. The primary disadvantage of minimally invasive ablative approaches is that if the goal is to totally ablate the entire prostate, then incontinence and erectile dysfunction will likely ensue in some cases. Another concern is deferring radical prostatectomy in cases that were understaged and possibly losing the window of opportunity to cure the cancer.

How effective is cryotherapy for whole-gland ablation?

Cryotherapy has been used as a primary treatment for prostate cancer since the early 1990s. In the past several years, long-term data have become available that suggest that cryotherapy is effective (Babaian RJ et al. J. Urol. 180:1993-2004 (2008); Jones JS et al. J. Urol. 180:554-558 (2009)).

One measure of the effectiveness of any treatment for prostate cancer is the residual PSA that can be detected after treatment. As with radiation therapy, a measurable PSA is often seen after cryotherapy, since there is often a very small amount of PSA-producing prostate tissue refractory to ablation. This small amount of PSA does not necessarily indicate a cancer recurrence. Most cryosurgeons employ the Phoenix ASTRO definition of PSA failure (nadir (lowest) point + 2.0). Recent studies have shown that a PSA of <0.6 at 3 months predicts a good outcome after cryotherapy (Levy DA et al. J. Urol. 182:931-7 (2009)). If the PSA rises above this level after cryotherapy, a repeat prostate biopsy is necessary to search for residual or recurrent cancer. Unlike after radiation therapy, a salvage or second cryotherapy procedure may be pursued. Alternatively, one may proceed to a radical prostatectomy.

What are the potential side effects of whole-gland cryotherapy?

All patients will experience urinary retention for the first 7 to 10 days after cryotherapy. Therefore, a urinary catheter is inserted into the bladder after the procedure and removed 7 to 10 days later. Long-term urinary retention is rare.

Cryotherapy is characterized by very low risks of urinary incontinence (less than 2%) and low risk for rectal injury (less than 0.5%). Most men do not experience a worsening in their urinary patterns.

The major side effect of whole-gland cryotherapy is erectile dysfunction. This occurs in all men immediately after whole-gland cryotherapy. Some men recover erectile function over the ensuing 2 to 3 years after treatment. Penile rehabilitation with a PDE5 inhibitor such as Viagra or Cialis and use of a vacuum erection device will improve the chances of recovering potency (Babaian RJ et al. J. Urol. 180: 1993-2004 (2008); Jones JS et al. J. Urol. 180: 554-558 (2009)).

How effective is HIFU for whole-gland ablation? Is it safe?

HIFU (high-intensity focused ultrasound) has been used in Europe and Asia for more than 10 years. Small studies have demonstrated the effectiveness of HIFU to control localized prostate cancer over a 10-year period. (Uchida T et al. Int. J. Urol. 2006; 13:228-233; and Uchida T et al. J. Urol. 2009; 181(4):228). Another recent study found that of patients with low-risk or intermediate-risk cancers who underwent HIFU with the Ablatherm, 83% were biochemically disease-free at 8 years. Control biopsies were negative between 3 and 6 months post-HIFU in 86% of patients (Blana et al. Eur. Urol. 53(6): 1194-1203 (2008)). One measure of the effectiveness of any treatment for prostate cancer is the residual PSA that can be detected after treatment.

As with radiation and cryotherapy, a measurable PSA may be seen after HIFU, since there is often a very small amount of PSA-producing prostate tissue that is not ablated after HIFU treatment.

Men with low- and intermediate-risk prostate cancer have enjoyed good outcomes with regards to PSA. Studies from Europe and Asia report that up to 90% of men have a negative prostate biopsy after HIFU, suggesting that HIFU is effective in eradicating prostate cancer (Murat FJ, Gelet A. Curr. Urol. Rep. 9(2):113-21 (2008); Murat FJ et al. Urol. Oncol. 26(6):683-4 (2008); Blana et al. Eur. Urol. 53(6): 1194-1203).

Incontinence risks are very low after HIFU. Nerve-sparing HIFU is possible, and 80%–90% of men are able to maintain erections after HIFU.

The major side effect of HIFU has been urethral stricture disease. Smilow Center surgeons have introduced modifications to the HIFU procedure that have reduced the risk of strictures to <5%. Smilow Center doctors are actively studying the effectiveness and side effects of HIFU.

Is it possible to receive HIFU even though it is not FDA approved?

The only way to receive HIFU in the United States is to participate in a clinical trial. The Smilow Center is one of a select group of investigative centers for this new technology.

HIFU is approved in Canada, Europe, Mexico and the Caribbean. Many of these facilities have a high safety record with HIFU procedures. USHIFU has set up treating facilities in Mexico and the Caribbean. One of the Smilow Center surgeons has performed the second highest number of HIFU procedures by an American Board of Urology–certified urologist. Smilow Center surgeons have accompanied hundreds of men with localized prostate cancer to Cancun, Mexico and Nassau, Bahamas to perform HIFU procedures. In many cases, American insurance carriers will reimburse a significant portion of the treatment costs.