Isocenter definition in Radiotherapy
Radiation therapy
Radiation therapy or radiotherapy, often abbreviated RT, RTx, or XRT, is therapy using ionizing radiation, generally as part of cancer treatment to control or kill malignant cells and normally delivered by a linear accelerator. Radiation therapy may be curative in a number o…
Full Answer
What is a Radiation isocenter?
Diameter of the radiation isocenter Diameter of the radiation isocenter The radiation isocenter (in contrast to the mechanical isocenter) is the point in space where radiation beams intersect when the Gantry is rotated during beam-on.
What is An isocentric technique?
An isocentric technique is where all beams used in a radiation treatment have a common focus point, a.k.a. the isocenter.
What is the mechanical isocenter in a gantry?
The idealized intersection point of the gantry axis of rotation with that of the collimator and treatment table is known as the mechanical isocenter. In practice, due to the heavy weight and mechanical imperfections of the system, the isocenter is not a single point and its location changes with the rotation of the gantry, collimator or couch.
What is the isocenter in Linac?
All of these movements in the modern linac occur around an axis that runs through the isocenter. In this way, if the centre of the target area in the patient's body is moved to coincide with the isocenter, then all motions of the machine will remain centred on the target.
How is a phantom positioned?
The phantom was positioned through the displacement as indicated by the TPS, between the reference marks made during CT with radiopaque markers and the isocentercoordinates of the simulation.
What is convergence of the three axes of rotation in radiation therapy?
The convergence of the three axes of rotation in radiation therapy; the intersecting point of the axis of rotation of the gantry, the collimator, and the treatment couch.
Why is the use of conductive materials in the vicinity of the scanner's isocentermust be limited?
However, the use of any conductive materials in the vicinity of the scanner's isocentermust be limited because of the potential for induced eddy currents to locally deform the magnetic field homogeneity.
What is the encompass used for?
According to Ofix, the Encompass has been used for intracranial radiotherapy treatments for nearly a year and is now cleared to achieve sub-millimeter immobilisation to precisely treat multiple lesions with a single isocenter.
What is the purpose of the previous method?
And it should be also noted that the purpose of the previous method was to enhance MTF at the isocenter, not to make MTF uniform across the FOV.
What is the idealized intersection point of the gantry axis of rotation with that of the collimator?
Definition. The idealized intersection point of the gantry axis of rotation with that of the collimator and treatment table is known as the mechanical isocenter. In practice, due to the heavy weight and mechanical imperfections of the system, the isocenter is not a single point and its location changes with the rotation of the gantry, ...
What is isocentric radiation?
An isocentric technique is where all beams used in a radiation treatment have a common focus point, a.k.a. the isocenter. Isocentric techniques require less patient repositioning as multiple field arrangements can be delivered with gantry and collimator movements, reducing treatment times.
How manyfold are the movements of the linear particle accelerator?
The movements of the linear particle accelerator (or linac) are threefold:
What is the smallest circle in a radiation isocenter circle?
The middle lines ("beams") of the three radiation stripes form a triangle when they intersect in the film center. The smallest circle which fits inside the triangle (all three beams have to intersect the circle or at least touch it) is usually called the radiation isocenter circle.
What is the radiation isocenter?
The radiation isocenter (in contrast to the mechanical isocenter) is the point in space where radiation beams intersect when the Gantry is rotated during beam-on. This statement is a simplification: gravitation has an influence on the mechanical parts inside the treatment head and therefore on beam direction.
