It is estimated that as many as a third of newly-diagnosed men have only one spot of cancer. These patients may be candidates for focal treatment. Focal cryotherapy is defined as the destruction of a section of the prostate gland by freezing. The known tumor site is treated, but the other lobe and surrounding structures are spared, improving the odds that sexual potency and urinary continence will be preserved.
Patient Selection for Focal Cryoablation
To be considered for focal cryoablation the patient must have unilateral prostate cancer, that is, cancer in only one lobe. In general, men with Sky are the preferred candidates for focal treatment, but Teal and even Azure cancers can also be considered. Focal cryotherapy may also be offered as a salvage therapy for Indigo.
The cryoablation procedure uses an extremely cold temperature to destroy the cancer tissue by circulating sub-zero Argon gas through cryoprobes strategically placed in the prostate. The combination of aggressive freezing at targeted locations within the prostate, while maintaining the integrity of the urethra, external sphincter, and contralateral lobe, including the neurovascular bundle, is the premise of focal cryoablation. The results of focal cryotherapy performed at other centers, as well as at ours, show long-term stable PSA levels in 75 to 85 percent of men treated in this fashion.
Three Essential Criteria for Successful Focal Treatment:
- Imaging visibility on scanning is necessary to achieve precise cancer mapping for successful focal therapy. Without clear identification of the tumor, focal therapy will end up being a blind approach, resulting in a suboptimal outcome.
- Unilaterality of the tumor in the prostate. Careful staging is necessary to ensure that focal therapy is appropriate. The risk of incomplete eradication of cancer is likely to be small in carefully screened men.
- A skillful practitioner. Since only a portion of the prostate is targeted, precision targeting of the cancer is paramount. Experience, clinical judgment, and proper training are essential for obtaining consistently satisfactory results.
Assuming all three of these criteria are met, focal treatment offers the potential for excellent cancer control with a relatively lower risk of erectile dysfunction and practically no risk of urinary problems.
Other Types of Focal Technology
There are many other technologies that may turn out to be equally effective for administering focal therapy such as High Intensity Focused Ultrasound (HIFU), Radiofrequency Tumor Ablation (RFTA), Microwave Thermal Ablation (MTA), Photodynamic Therapy (PDT), Focal Brachytherapy, or Nanotech-Laser treatment. Focal therapy, accomplished by these other methodologies, however, is a very new area of prostate cancer therapy. There is relatively little long-term experience at centers offering focal therapy. Our reliance at the Prostate Institute of America on color Doppler, an imaging technology that has existed for over 20 years, has enabled us to hone our cryotherapy skills and build up clinical experience for more than 10 years.
Duke Bahn, MD is the Director of the Prostate Institute of America. Certified by the American Board of Radiology, his special areas of interest are the early detection and staging of prostate cancer using color-Doppler ultrasound with tissue harmonics. He is also a pioneer in using cryotherapy, as both a primary and salvage treatment for prostate cancer. His published data was the impetus for obtaining Medicare approval for cryotherapy as a viable treatment for prostate cancer. Dr. Bahn has held many academic and professional appointments, including clinical professor of urology, Keck School of Medicine, University of Southern California.