Isocenter
Pronunciation: EYE-so-sen-ter
The point in space where radiation beams from different gantry angles converge, typically placed within or near the target volume.
Full Definition
The isocenter is a fundamental concept in radiation therapy representing the mechanical and dosimetric center of the treatment machine where beams from all gantry angles intersect. This point serves as the reference for dose calculations and beam geometry, and is typically positioned within or near the center of the target volume during treatment planning. Accurate isocenter placement and verification are critical for precise dose delivery, and modern systems include sophisticated imaging and positioning technologies to ensure reproducible isocenter alignment for each treatment fraction.
Usage
Usage note: Sometimes abbreviated as 'ISO' in clinical notes, but should be written fully in formal reports.
In Context
- "The isocenter was positioned at the geometric center of the planning target volume." — Treatment planning summary
- "Daily imaging verification ensures accurate patient alignment to the planned isocenter." — Quality assurance protocol