tissue phantom ratio
Dosimetric parameter comparing radiation dose in tissue to dose in a reference phantom condition.
Full Definition
Tissue phantom ratio (TPR) is a fundamental dosimetric concept used in radiation therapy to characterize how radiation dose varies with depth in tissue-equivalent materials. TPR measurements compare the dose at a specific depth in a phantom to the dose at a reference depth under identical beam conditions, providing essential data for accurate dose calculations in treatment planning systems. These ratios account for beam attenuation, scatter contributions, and energy spectrum changes as radiation traverses tissue, forming the basis for percentage depth dose calculations in clinical practice.
Usage
Usage note: Often abbreviated as TPR in clinical contexts; spell out in patient-facing documentation.
In Context
- "The tissue phantom ratio data was essential for accurate depth dose calculations." — Physics commissioning report
- "TPR measurements validated the beam model implementation in the treatment planning system." — Quality assurance protocol