Cryosurgery
Cryosurgery in Cancer Treatment
What is cryosurgery?
Cryosurgery (also called cryotherapy) is the use of extreme cold produced by liquid nitrogen (or argon gas) to destroy abnormal tissue. Cryosurgery is used to treat external tumors, such as those on the skin. For external tumors, liquid nitrogen is applied directly to the cancer cells with a cotton swab or spraying device.
Cryosurgery is also used to treat tumors inside the body (internal tumors and tumors in the bone). For internal tumors, liquid nitrogen or argon gas is circulated through a hollow instrument called a cryoprobe, which is placed in contact with the tumor. The doctor uses ultrasound or MRI to guide the cryoprobe and monitor the freezing of the cells, thus limiting damage to nearby healthy tissue. (In ultrasound, sound waves are bounced off organs and other tissues to create a picture called a sonogram.) A ball of ice crystals forms around the probe, freezing nearby cells. Sometimes more than one probe is used to deliver the liquid nitrogen to various parts of the tumor. The probes may be put into the tumor during surgery or through the skin (percutaneously). After cryosurgery, the frozen tissue thaws and is either naturally absorbed by the body (for internal tumors), or it dissolves and forms a scab (for external tumors).
Read the full article on the National Cancer Institute website.
Focal Cryoablation – Prostate cancer
This 2023 study looked at 163-patients who underwent Focal Cryoablation of the prostate at a single clinic by a physician from November 2008 to December 2020.
The patient cohort included 27 patients with low, 115 patients with intermediate, and 23 patients with high-risk prostate cancers. At five years, this cohort yielded biochemical disease-free recurrence rates of 78%, 74%, and 55% for low, intermediate, and high-grade cancers, respectively.
The study concluded: The extent of FC’s efficacy still remains to be established, but our conclusions demonstrate favorable PSA kinetics at five years follow-up. Common complications such as erectile dysfunction and urinary incontinence were minimal but still present in the patient cohort.
The study also included the following on other types of ablation:
Different modalities of targeted focal ablation are available, including HIFU, focal laser ablation, radiofrequency ablation, photodynamic therapy, and cryoablation. The technology for cryoablation has been present for many years; hence, it is a common modality for focal ablation of the prostate. It is, however, valuable to note the efficacy and growing body of literature around alternative focal therapy modalities. Guillaumier S et al. (2018) focused on five-year oncologic outcomes after HIFU and found 88% failure-free survival in treating non-metastatic PCa [prostate cancer] in a 625 multi-center cohort. Musunuru HB et al. (2016) support active surveillance for low and intermediate-risk PCa with 15-year metastasis-free survival rates ranging from 64% to 94%. Azzouzi AR et al. (2017) performed the first randomized clinical trial and assigned a 413 low-risk PCa patient cohort to photodynamic therapy or active surveillance. This study found that at two years of follow-up, there were lower rates of histologic progression from photodynamic therapy (28%) rather than active surveillance (58%). The study additionally found that focal therapy reduced the rate of radical therapy for PCa from 53% to 24% in four years.
Updated 2024