Radiosurgery is a technique used in oncology with the aim of offering patients a wider spectrum of intervention for the treatment of the disease, alongside the already consolidated surgical, farmacological and and radiotherapy practices.
With this technology it is possible to send a high dose of ionizing radiation, coming from an external source, to a target (solid tumor) inside the body whose position, shape and size is known. Unlike traditional radiation therapy which is much less precise and uses radiation at lower doses, the radiation dose emitted with radiosurgery is such as to destroy the diseased tissue with surgery precision (hence the name radio-surgery) therefore without going to damage nearby tissues as in the case of radiation therapy.
With radiosurgery, solid tumor lesions can be destroyed or functional disorders such as epilepsy, Parkinson’s disease, chronic drug-refractory pain (for example, trigeminal neuralgia) and many other disorders can be treated.
The most used radiosurgery is stereotaxic which allows to deliver in a few sessions, from 1 to 5, of 1 hour each, the radiation on a small target, thus limiting the damage on the surrounding healthy tissues. With traditional radiotherapy several sessions are necessary (even 30).
Radiosurgery is performed using two radiation accelerating tools called Gammaknife and Cyberknife which represent a valid alternative to surgery especially in two circumstances:
- in patients with localized but inoperable cancer due to the infiltration of the disease into adjacent organs
- in patients with disease recurrence in sites previously irradiated with traditional radiotherapy.
The system is completely non-invasive and can be performed in day-hospital or on a purely outpatient basis. This aspect is not to be underestimated: radiosurgery, and especially cyberknife, eliminates the long hospitalization times typical of surgery.
Does cyberknife have any advantages over gammaknife?
- the gamma knife can only treat the area of the skull while the cyberknife, given its mobility (6 degrees of freedom and about 1200 different positions), can treat any other body district. The trend of patients treated with cybernkife in extracranial districts is increasing significantly *. It is a limit to think today of radiosurgery as a technique suitable only for the brain or applicable only to this, especially after considering that the most frequent tumors, in women and men, are extracranial **.
- the gamma knife, for the immobilization of the patient, uses helmets that are fixed to the patient’s skull (under local anesthesia). The cyber knife, instead, uses thermoplastic masks that are adapted to the skin surface of the area to be treated.
- with the gamma knife, unlike cyberknife, the treatment cannot be split because of the use of fixed helmets.
- Cyber knife is the only system in the world that allows treatments with an accuracy of 1.5 mm on lesions that move with the breath.
- with the gamma knife a radioactive substance (radioactive cobalt) is used as the source of radiation, not used with cyberknife.
The main limitation of the two methods is represented by the size of the tumor: lesions greater than 2.5 – 3 cm cannot be treated with radiosurgery.
Cyberknife, for all these reasons, represents an absolute innovation in the field of radiosurgery, differentiating itself from any other equipment on the market today.
* trend of patients treated with radiosurgery by means of the cyberknife system for the various body areas
** image i number of cancer in Italy 2018