Related Experiment Video
Updated: May 15, 2026
11:38
Voluntary Breath-hold Technique for Reducing Heart Dose in Left Breast Radiotherapy
Published on: July 3, 2014
Technical note: contrast solution density and cross section errors in inhomogeneity-corrected dose calculation for
Leonard H Kim1, Miao Zhang, Roger W Howell
1Department of Radiation Oncology, University of Medicine and Dentistry of New Jersey, NJ, USA. kimlh@umdnj.edu
Medical Physics
|January 10, 2013
Summary
Accurate breast brachytherapy requires precise material properties. This study found contrast solution density errors in treatment planning systems, which can be corrected by overriding density values to improve dose calculation accuracy.
Area of Science:
- Medical Physics
- Radiotherapy
- Brachytherapy
Background:
- American Association of Physicists in Medicine Task Group 186 highlights the need for accurate material property data in brachytherapy.
- Radiographic contrast is commonly used in breast brachytherapy balloons.
Purpose of the Study:
- To independently estimate the properties of radiographic contrast solution used in breast brachytherapy.
- To identify potential inaccuracies in commercial brachytherapy dose calculation algorithms regarding contrast material properties.
Main Methods:
- Determined mass density and atomic weight fractions of contrast solution using manufacturer data.
- Verified mass density via measurement and compared it to CT calibration data.
- Calculated photon interaction cross section for a high-dose-rate (HDR) brachytherapy source and compared it to muscle.
Main Results:
- Contrast solution density was 10% lower than CT calibration values.
- Contrast solution's photon interaction cross section was 1.2% higher than muscle's.
- Density overrides in treatment planning systems can correct these discrepancies.
Conclusions:
- Estimated errors in mass density and cross-section parameters for contrast used in breast brachytherapy.
- The methodology is adaptable for other clinics to assess dose calculation errors.
- Implementing density overrides can enhance dose calculation accuracy in clinical practice.
