Irreversible electroporation (IRE, NanoKnife®) is a type of focal therapy which has been suggested as an alternative to radical treatment. It typically uses 3 to 5 electrodes which deliver short repetitive electrical pulses to destroy the cancer cells. Stereotactic radiotherapy (stereotactic body radiation therapy or SBRT) is a type of external radiation in which a higher radiation dose is delivered in a reduced number of fractions as is the case with conventional or moderately fractionated radiation therapy. Proton therapy (PT) is a further type of external radiation therapy which uses high doses of ionising rays directed at the tumour.

For IRE only one observational study with more than 50 patients could be identified; there were no (R)CTs available for this intervention. Also for SBRT only (25) observational studies and no (R)CTs are available. For PT five RCTs were identified. Due to a lack of comparative studies, no conclusions regarding the effectiveness (overall survival and quality of life) of IRE or SBRT were possible. For PT, there is no evidence that suggests that proton therapy in varying doses and fractions confers any advantage regarding overall survival and quality of life. The safety endpoints showed a high degree of acute side effects, but also late side effects.

The conclusion is accordingly that there is at present inadequate and insufficient evidence to show that IRE, SBRT and PT have either a positive impact on survival and quality of life or the ability to prevent or delay prostatectomy.