Definition of Stereotactic Radiosurgery (SRS)
Stereotactic Radiosurgery (SRS) is a special form of ionizing radiation therapy characterized by maximum accuracy (<1mm), delivering a large dose of radiation to a strictly defined target, in a single session.
In special cases (i.e big size of the target or its proximity to a nerve or sensitive structure) SRS can be performed in 3 or 5 sessions (fractionated Stereotactic Radiosurgery) or in one session which is then repeated after several months or years. (staged Stereotactic Radiosurgery).
SRS definition given by various internationally recognized scientific institutes and associations, as well as health organizations:
• National Cancer Institute – NCI (USA)
A type of external radiation therapy that uses special equipment to position the patient and precisely give a single large dose of radiation to a tumor. It is used to treat brain tumors and other brain disorders that cannot be treated by regular surgery. It is also being studied in the treatment of other types of cancer.
• American Society Therapeutic Radiation Oncology-ASTRΟ (USA)
Stereotactic radiosurgery (SRS) is a distinct discipline that utilizes externally generated ionizing radiation in certain cases to inactivate or eradicate a defined target(s) in the head or spine without the need to make an incision. The target is defined by high-resolution stereotactic imaging.
To assure quality of patient care the procedure involves a multidisciplinary team consisting of a neurosurgeon, radiation oncologist and medical physicist.
Stereotactic radiosurgery typically is performed in a single session, using a rigidly attached stereotactic guiding device, other immobilization technology and/or a stereotactic image-guidance system, but can be performed in a limited number of sessions, up to a maximum of five. Technologies that are used to perform SRS include linear accelerators, particle beam accelerators and multi-source Cobalt 60 units. In order to enhance precision, various devices may incorporate robotics and real time imaging.
• American Association of Neurological Surgeons – AANS (USA)
(Approved by the American Association of Neurological Surgeons, the Congress of Neurological Surgeons, and the American Society for Therapeutic Radiology and Oncology)
Stereotactic Radiosurgery (SRS) is a distinct discipline that utilizes externally generated ionizing radiation in certain cases to inactivate or eradicate (a) defined target(s) in the head and spine without the need to make an incision. The target is defined by high-resolution stereotactic imaging. To assure quality of patient care the procedure involves a multidisciplinary team consisting of a neurosurgeon, radiation oncologist, and medical physicist.
SRS typically is performed in a single session, using a rigidly attached stereotactic guiding device, other immobilization technology and/or a stereotactic image-guidance system, but can be performed in a limited number of sessions, up to a maximum of five.
Technologies that are used to perform SRS include linear accelerators, particle beam accelerators, and multisource Cobalt 60 units. In order to enhance precision, various devices may incorporate robotics and real time imaging.
• American Association of Physicists in Medicine – AAPM (USA)
Stereotactic radiosurgery (SRS) of an intracranial lesion, or radiosurgery, combines the use of a stereotactic apparatus and energetic radiation beams to irradiate the lesion with a single treatment.