Related Experiment Video
Updated: May 5, 2026
08:34
Proton Therapy Delivery and Its Clinical Application in Select Solid Tumor Malignancies
Published on: February 6, 2019
20.6K
Improving spot-scanning proton therapy patient specific quality assurance with HPlusQA, a second-check dose
Dennis Mackin1, Yupeng Li, Michael B Taylor
1Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030.
Medical Physics
|December 11, 2013
Summary
HPlusQA software effectively validates spot-scanning proton therapy dose calculations, reducing patient-specific quality assurance needs by 64%. This enhances the efficiency and effectiveness of the proton therapy quality assurance process.
Area of Science:
- Medical Physics
- Radiation Oncology
- Computational Dosimetry
Background:
- Patient-specific quality assurance (PSQA) is crucial for verifying proton therapy treatment plans.
- Accurate dose calculation software is essential for reliable PSQA.
- Current PSQA workflows can be time-consuming and resource-intensive.
Purpose of the Study:
- To validate HPlusQA, a spot-scanning proton therapy (SSPT) dose calculation software, as a second-check tool for PSQA.
- To assess HPlusQA's utility within existing PSQA frameworks.
- To evaluate HPlusQA's ability to predict discrepancies between treatment planning system calculations and measured doses.
Main Methods:
- Compared HPlusQA and Eclipse treatment planning system dose calculations against 106 planar dose measurements from PSQA.
- Analyzed calculated versus measured point doses to determine correlation and relative performance.
- Utilized gamma index scores to compare HPlusQA and Eclipse predictions against measured dose tolerances.
- Introduced the alpha-beta-gamma (αβγ) transformation for simplified gamma score comparison.
Main Results:
- Both HPlusQA and Eclipse calculations agreed within 2 cGy of measurements for relative depths <80%, falling to 4 cGy for depths >80%.
- HPlusQA correctly predicted Eclipse's adherence to tolerance levels 92% of the time for dose calculation and 79% of the time for predicting when tolerance levels were exceeded.
- A positive correlation (up to 0.6) was observed between dose discrepancies, except for relative depths <10% where a negative correlation (-0.21) was noted.
Conclusions:
- HPlusQA demonstrated reasonable effectiveness (79% ± 10%) in identifying when Eclipse calculations exceeded acceptable dose and distance-to-agreement tolerances.
- Implementing HPlusQA as a second-check tool can potentially reduce the need for PSQA measurements by 64%.
- HPlusQA integration can improve the overall efficiency and effectiveness of proton therapy quality assurance processes.
