An alternative to gamma histograms for ROI-based quantitative dose comparisons.

Area of Science:

• Medical Physics
• Radiation Oncology
• Image Analysis

Background:

• Quantitative comparison of radiation dose distributions is crucial for treatment planning.
• Gamma analysis is a standard tool, but gamma histograms have limitations.
• Region of Interest (ROI)-based analysis requires robust quantitative metrics.

Purpose of the Study:

• To propose an alternative to standard gamma histograms for ROI-based gamma analysis.
• To provide a method that yields more informative quantitative comparisons of dose distributions.
• To enhance decision-making in treatment plan acceptance or rejection.

Main Methods:

• Developed a method to find minimum dose difference and distance-to-agreement thresholds for gamma analysis.
• Ensured a pre-set fraction of the Region of Interest (ROI) passes the gamma test.
• Calculated pass rates per gamma calculation for quantitative comparison.

Main Results:

• The proposed method provides more information than standard gamma histograms regarding pass rates.
• Achieved these results with negligible additional computational cost.
• Demonstrated no loss of accuracy compared to existing methods.

Conclusions:

• The new method is a valuable and complementary alternative to standard gamma histograms.
• It increases both the quantity and quality of information for evaluating dose distributions.
• Facilitates more informed acceptance or rejection decisions in radiation therapy.