The prostate is a gland located around the urinary outlet of the bladder in the male body. About the size of a chestnut, the prostate is composed of two side-by-side lobes connected in the front by a narrowed part of the gland and from behind by a middle lobe that lies above and between the ejaculatory ducts. The gland secretes a milky fluid that is discharged by excretory ducts into the prostatic urethra at the time of emission of semen.
Cryosurgical ablation of the prostate (CSAP), also known as cryosurgery of the prostate gland, reduces the size of the prostate gland by using extremely cold temperatures to destroy abnormal prostate tissue. Cryosurgical ablation of the prostate is performed by inserting a probe through an opening in the perineum to apply a freezing agent, such as liquid nitrogen, to the prostate gland and the probe is guided by transrectal ultrasonography.
The procedure modality involves either complete ablation of the prostate or focal ablation (subtotal cryoablation) only targeting diseased tissue while leaving normal tissue intact. In 2017, the American Urological Association, along with the American Society for Radiation Oncology and the Society for Urologic Oncology updated their joint guidelines on the management of clinically localized prostate cancer which included recommendations on focal treatment for low-risk and intermediate-risk prostate cancer patients stating that focal therapy is not a standard care option because comparative outcome evidence is lacking. In addition, focal therapy for individuals with high-risk localized prostate cancer is not recommended outside of a clinical trial.
For whole gland cryoablation as initial treatment for localized prostate cancer, the evidence includes several systematic reviews, two randomized controlled trials, and many comparative and noncomparative observational studies. Relevant outcomes are overall survival, disease-specific survival, symptoms, functional outcomes, quality of life, and treatment-related morbidity. High-quality data comparing cryoablation with external-beam radiotherapy, radical prostatectomy, or active surveillance are lacking, but available data have suggested similar overall survival and disease-specific survival rates compared with radical prostatectomy and external-beam radiotherapy. The evidence is sufficient to determine that the technology results in a meaningful improvement in the net health outcome.
For whole gland cryoablation as salvage treatment for a recurrence of localized prostate cancer following radiotherapy, the evidence includes primarily noncomparative case series and a few retrospective studies comparing salvage cryoablation with salvage prostatectomy. Relevant outcomes are overall survival, disease-specific survival, symptoms, functional outcomes, quality of life, and treatment-related morbidity. High-quality data comparing cryoablation with prostatectomy was mixed, and evidence comparing cryotherapy with brachytherapy is lacking. Individuals in this group have few options and prostatectomy can be difficult in tissue that has been irradiated. The evidence is sufficient to determine that the technology results in a meaningful improvement in the net health outcome.