Anatomy-corresponding method of IMRT verification
Janusz Winiecki1, Zbigniew Zurawski1, Barbara Drzewiecka1
1Medical Physics Department, Oncology Center, ul. I. Romanowskiej 2, 85-796 Bydgoszcz, Poland.
Summary
This study introduces a new method for verifying dynamic intensity-modulated radiation therapy (IMRT) plans, improving the accuracy of dose distribution analysis. The technique helps pinpoint dose anomalies for better treatment quality assurance.
Area of Science:
- Medical Physics
- Radiation Oncology
- Dosimetry
Background:
- Conventional quality assurance (QA) for intensity-modulated radiation therapy (IMRT) often fails to detect significant local dose discrepancies.
- Existing methods provide limited information, focusing on overall detector area rather than irradiated tissue volume.
Purpose of the Study:
- To develop and validate a novel verification procedure for dynamic IMRT plans.
- To enable visualization and precise localization of dose distribution anomalies in specific tissues.
Main Methods:
- The study utilized a Gamma Evaluation concept for plan verification.
- A custom software, GammaEval, was developed for calculations and generating 2D gamma (γ) images and histograms.
- Portal and film dosimetry data were used to register dose distributions.
Main Results:
- Over 150 dose distribution maps were analyzed using the developed method.
- Cross-examination of gamma images with digitally reconstructed radiographs (DRRs) was performed to validate findings.
Conclusions:
- The developed method allows for accurate localization of deviations between planned and delivered doses.
- Complex treatment monitoring is feasible through cross-examination of gamma images and DRRs, enhancing IMRT plan verification.
