central axis dose
The radiation dose delivered along the central beam axis, serving as a reference point for dose calculations and field arrangement.
Full Definition
Central axis dose refers to the radiation dose measured or calculated along the geometric center line of a radiation beam, extending from the radiation source through the patient to the exit point. This measurement serves as a fundamental reference for dose calculations, beam commissioning, and treatment plan verification. The central axis dose profile varies with depth due to beam attenuation, scatter radiation, and other physical factors that must be accurately modeled in treatment planning systems. Understanding central axis dose characteristics is essential for medical physics quality assurance and for medical editors reviewing dosimetric studies where beam characteristics and dose distributions are analyzed.
Usage
Usage note: Fundamental reference for dosimetric measurements and calculations. Often abbreviated as CAX in technical contexts.
In Context
- "The central axis dose measurements validated the treatment planning system calculations." — Quality assurance report
- "Beam commissioning required central axis dose profiles at multiple depths and field sizes." — Medical physics procedure