Components in Radiosurgery
What are the components of the radiosurgery system?
Stereotactic radiosurgery requires certain key tools and technologies, such as a computer that uses specialized treatment-planning software, a moveable source of high-energy radiation (medical linear accelerator), devices to shape the radiation beams, and quality-assurance tools, such as an x-ray imager, which is used to check the patient’s position relative to the radiation beam before treatment begins:
Imaging, beam adjustment, and patient positioning all work together for the most advanced radiation treatment.
Computer & software. An onboard computer and sophisticated software helps Aria’s team to analyze three-dimensional images of cancer lesions and surrounding anatomy to determine the optimal way to treat each patient’s condition. The resulting treatment plan – unique to each individual – specifies the number of radiation beams as well as the angles required to deliver the radiation. The system’s software sums the energy of the beams to identify exactly the right amount of treatment, and the correct configuration of radiation, to destroy the tumor.
- Medical linear accelerator. A powerful, specially designed linear accelerator generates the radiation beams for treatment.
- Beam-shaping devices. Radiosurgery systems rely primarily on one of two types of devices to limit and direct radiation beams –
- Aria’s team uses a hollow metal component, referred to as a cone, to treat small tumors or abnormalities. Cones have outlets of various sizes that will correspond to the volume and shape of the targeted tumor.
- Alternatively, the Aria specialists may use a multileaf collimator – a highly engineered, boxed, gridlike structure resembling a multidirectional pin screen – to address larger tumors. The collimator has 120 computer-controlled tungsten metal fingers, or leaves, that the system can individually adjusted to create an aperture of almost any shape, to form to the anatomy of the targeted tumor and its surroundings. The radiation beam passes through this aperture and is shaped by it.
Leaves on collimator shift to accomodate different irradiation angles by the linear accelerator, in order to continuously match beam shape to target tissue.
- X-ray imager. With the radiosugery system shaping the radiation beam so exactly, the treatment team must aim the beam with great precision. The system uses a special x-ray imager or CT imager, built into the radiation therapy unit, to check patient position relative to the radiation beam before treatment begins.
- Treatment table. A highly engineered, remotely controlled table permits the team to make extremely fine adjustments to the treatment couch to position the patient for radiotherapy.