Isocenter
|
|
This article needs additional citations for verification. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed. (March 2007) |
Isocenter in aerial photography: A point where a line meets at 90-angle of tier/2. It is the point on the aerial photo platform that falls on a line half-way between the Principal point and the Nadir point. In imaging physics and radiation oncology, the isocenter is the point in space through which the central ray of the radiation beams pass.
In radiation oncology there is typically talk of two isocenters:
- radiation isocenter and
- mechanical isocenter.
Radiation isocenter is the point in space through which the central beam of radiation passes whereas mechanical isocenter is the point where optical beams intersect.
The placement of the radiation isocenter plays an important role in treatment planning because ideally the isocenter should be placed in the center of the target volume, usually a tumor. Patient positioning, usually via 3D imaging methods, is thus essential for the successful irradiation of cancerous tissue and - consequently - the treatment outcome.[1]
The source to isocenter distance (SIsoD) can be an important parameter to control in determining patient exposure and image quality in diagnostic computed tomography and fluoroscopy.
[edit] References
- ^ Quantification Of Shift In Isocenter For 2-Dimensional And 3-Dimensional Radiotherapy Plans For Various Common Treatment Sites, The Internet Journal of Oncology