Prostatic cryotherapy utilizes cold temperatures to treat prostate diseases. This concept is not new but has been explored in various forms over the last few decades. Cryotherapy has more recently been revisited for the treatment of prostate cancer with the introduction of new cryotherapy techniques and technology.
Modern prostatic cryotherapy is performed in the operating room with the patient under anesthesia. An ultrasound probe is placed in the patient's rectum, allowing the surgeon to see the prostate on the ultrasound screen throughout the treatment. Using ultrasound guidance, several needles are first placed directly through the patient's skin ("percutaneously"), behind his scrotum and in front of the rectum (anatomically, this small area is called the "perineum"). The surgeon can see each needle entering the prostate with the transrectal ultrasound and can guide its exact placement. Through the resulting needle tracks, which are gradually enlarged or dilated by the surgeon, larger metal probes are eventually placed into the substance of the prostate gland.
These metal "cryoprobes" are hollow, and once in place in the prostate, liquid nitrogen is circulated through each probe to become extremely cold. The prostate tissue immediately around each cryoprobe is frozen, and nearby prostate regions undergo differing degrees of cold thermal injury. In theory, all prostate cancer is intended to be frozen and killed due to cryotherapy. After the cryotherapy operation, the cryoprobes are removed from the patient, who has several tiny incisions in the skin behind his scrotum, which the surgeon closes with a few individual stitches. A urinary catheter or drainage tube is typically left in the bladder for one or two weeks following cryotherapy since patients cannot urinate immediately after the operation.
Most patients undergoing prostatic cryotherapy will spend one or two nights in the hospital. Patients with very large prostates are generally not considered good candidates for treatment with cryotherapy for prostate cancer. In some cases, hormonal therapies can shrink the prostate before cryotherapy. Early attempts to perform cryotherapy for prostatic disease were abandoned mainly because of relatively severe and frequent complications. Over the last few years, newer technology, including transrectal ultrasound imaging and tiny temperature probes to guide treatment, has made prostatic cryotherapy much safer and easier, leading to renewed interest in this approach. Nonetheless, severe complications, including urinary incontinence, sloughing of the urethra, and damage to the rectum, still can occur even with modern prostatic cryotherapy techniques.
New techniques are still being developed and studied to limit further the complications associated with prostatic cryotherapy.At this point, very few urologists at very few medical centres have an extensive experience with cryotherapy for prostate cancer, and prostatic cryotherapy using modern technology has been practised for too few years to be able to judge its long-term effectiveness as a treatment for prostate cancer. For these reasons, most prostate cancer experts still consider this an investigational or experimental therapy. Thus, most urologists do not offer prostatic cryotherapy as a standard treatment option for patients with localized prostate cancer.
Clinical studies are currently being performed to examine the use of prostatic cryotherapy in highly selected patients, including those whose prostate cancer has grown back after failure of radiation therapy or with locally advanced prostate cancer extending outside of the anatomic confines of the prostate gland. Interested patients who feel they might be candidates for treatment with prostatic cryotherapy may seek a referral to the specialized cancer centres where such studies are being performed.