By Dr. Elie Haddad
Oncologist Radiothérapeuthe – HARTMANN Centre
Prostate cancer is the most common cancer in men over 50 years, and there was little to three main treatment options: surgery, brachytherapy and external beam radiotherapy. In recent years, appeared the CyberKnife treatment, such as brachytherapy, uses targeted radiation precisely and at very high doses, but without the invasive side of this technology.
Presentation and advantages of the CyberKnife
The robotic stereotactic radiosurgery system CyberKnife allows treating tumors (in particular of the prostate) by targeting with high accuracy to deliver high doses of 150 to 200 ray beams.
– The system includes a particle accelerator mounted on a robotic arm moving in all directions. It delivers radiation for hundreds of angles (for less than ten in conventional systems) and is therefore capable of targeting the prostate with high accuracy.
– An imaging device associated with it which makes it suitable to avoid irradiating non-tumor areas, following continuous and real-time frequent and permanent random movements of the prostate, and by automatically correcting the orientation of radiation administered.
– Its accuracy is thus less than a millimeter: it allows to target hard to reach areas, this sparing healthy tissue adjacent to the tumor area and consequently increasing the radiation dose administered to each session
In order to view the prostate imaging, it is necessary to implant the gold grains in the prostate (trustees) to the number of three or four according to very specific criteria. This possible increase doses enables destruction of the tumor in 80% of cases.
– The number of sessions bound to the necessary splitting radiation is thereby reduced to a few (5-6), compared to more than thirty several weeks for a conventional radiation therapy system, that, with an efficiency similar (see next paragraph). However, the biological impacts generated by high radiation doses impose a time limit for assessing results between 4 and 6 months.
– The treatment is very specific (including avoiding irradiating needlessly and dangerously rectum and bladder), low total duration and without invasive procedure has few side effects on the quality of life of patients because of its lower impact , including urinary incontinence, erectile function, rectal or bowel.
And it also allows the prostate re-irradiation in case of local recurrence after conventional external beam with excellent tolerance and high efficiency. In these cases restatement of the establishment of an inter-prostato rectal gel provides additional protection of the rectal wall.
– This technique greatly limits the duration of work stoppages and the number of transports home – radiological center.
Effectiveness of treatment with the CyberKnife System
The survival rate at 5 years after use of the CyberKnife are of the order of 90%, which is similar to those of other radiation treatments.
A satisfaction survey conducted in 2011 by the company selling the system on the 300 patients who used, provided the following results: over 90% of people are satisfied with the results of their treatment (to the point to make the same choice if applicable) and its low impact on their daily lives, and would recommend around them.
An independent international study called “PACE” (Prostate Advances in Comparative Evidence), was launched in early 2012 and several years to objectively compare the various options for CyberKnife treatments.
Presentation of the CyberKnife (French)
Emis par le distributeur de CyberKnife (English)
The CyberKnife among treatment options (French)
Effectiveness of the CyberKnife