treatment isocenter
The geometric point in space where radiation beams intersect during treatment delivery, serving as the reference for dose calculations.
Full Definition
The treatment isocenter is the precisely defined three-dimensional coordinate point where all radiation therapy beams converge during treatment delivery. This geometric reference point serves as the origin for dose calculations and beam geometry in treatment planning systems. The isocenter is typically positioned within or near the target volume and remains fixed while the linear accelerator gantry, collimator, and treatment couch rotate around it. Accurate isocenter positioning is critical for treatment delivery precision, with setup tolerances typically maintained within 1-3mm of planned coordinates through image guidance and verification procedures.
Usage
Usage note: May be shortened to 'isocenter' in radiation therapy contexts
In Context
- "The treatment isocenter was positioned 2cm superior to the surgical clips." — Treatment planning documentation
- "CBCT verification confirmed isocenter accuracy within 1mm of planned coordinates." — Treatment verification record