In addition to the therapies applied in our center established forms of therapy with reliable long-term results from international studies, other clinics also use treatments - including cryotherapy - whose efficacy has not been proven or is not yet sufficiently proven, or whose long-term side effects are unknown.

Cryotherapy is the controlled destruction of tissue (e.g. the prostate) by repeated freezing and thawing. In this process, two different cell-destroying processes are triggered. One is cell dehydration caused by extracellular freezing with accompanying increase in intracellular concentration of salts, and the other is intracellular freezing. Nowadays, cryotherapy is performed by means of argon and helium gases mediated cold and heat cycles. Similar to brachytherapy, cryoprobes (needles 1.47 mm in diameter) are positioned transperineally in the prostate using a perforated template. Argon and helium can then circulate alternately in the probes, with icing caused by gas expansion (the so-called Joule-Thomson effect; pressure drop causes heat loss; as an example, consider the balloon that is allowed to deflate quickly) leading to the formation of ice specifically at the needle tips. The use of many of these very thin needles, the temperature sensors, the good controllability of the cold and heat supply as well as the ultrasound monitoring of the frostbite allow a largely uniform temperature distribution within the prostate with fairly good demarcation from the surrounding tissue.

Like radical surgery and brachytherapy, cryotherapy is a so-called local therapy and is therefore only suitable for localized prostate carcinomas. Some studies show therapeutic success in the short follow-up period similar to or worse than that of surgery and radiotherapy (1,2). The disadvantage of cryotherapy is the relative incidence of urinary incontinence (up to 4.8%) and the absolute incidence of impotence (erectile dysfunction 80% after 18 and 76% after 24 months) (3,4). Because of this side effect profile, we currently believe that cryotherapy is only suitable for secondary treatment in recurrent prostate cancer.

1. Pisters LL et al. Salvage cryoablation: initial results from the cryo on-line data registry. J Urol. 2008 Aug;180(2):559-63
2. Ng CK et al. Salvage cryoablation of the prostate: follow-up and analysis of predictive factors for outcome. J Urol. 2007 Oct;178(4 Pt 1): 1253-7
3. Jones JS et al. Whole gland primary prostate cryoablation: initial results from the cryo on-line data registry. J Urol. 2008 Aug;180(2):554-8
4. Asterling S et al. Prospective evaluation of sexual function in patients receiving cryosurgery as a primary radical treatment for localized prostate cancer. BJU Int. 2008 Sep 12 (Epub ahead of print).