Related Experiment Video
Updated: Dec 14, 2025
Voluntary Breath-hold Technique for Reducing Heart Dose in Left Breast Radiotherapy
Published on: July 3, 2014
Dosimetric impact of baseline drift in volumetric modulated arc therapy with breath holding
Shunsuke Ono1, Yoshihiro Ueda1, Shoki Inui1
1Department of Radiation Oncology, Osaka International Cancer Institute, 3-1-69 Otemae, Chuou-ku, Osaka, 537-8567, Japan.
Background:
We investigated the change of dose distributions in volumetric modulated arc therapy (VMAT) under baseline drift (BD) during breath holding.
Materials And Methods:
Ten VMAT plans recalculated to a static field at a gantry angle of 0° were prepared for measurement with a 2D array device and five original VMAT plans were prepared for measurement with gafchromic films. These measurement approaches were driven by a waveform reproducing breath holding with BD. We considered breath holding times of 15 and 10 s, and BD at four speeds; specifically, BD0 (0 mm/s), BD0.2 (0.2 mm/s), BD0.3 (0.3 mm/s), and BD0.4 (0.4 mm/s). The BD was periodically reproduced from the isocenter along the craniocaudal direction and the shift during breath holding (ShiftBH) ranged 0-6 mm.The dose distribution of BD0.2, BD0.3 and BD0.4 were compared to that of BD0 using gamma analysis with the criterion of 2%/2 mm.
Results:
The mean pass rates of each ShiftBH were 99.8% and 98.9% at 0 mm, 96.8% and 99.4% at 2 mm, 94.9% and 98.6% at 3 mm, 91.5% and 98.4% at 4 mm, 70.8% and 94.1% at 4.5 mm, and 55.0% and 83.6% at 6 mm for the array and film measurements, respectively.
Conclusion:
We found significant differences in ShiftBH above 4 mm (ρ < 0.05). Hence, it is recommended that breath holding time should be shortened for patients to preserve the reproducibility of dose distributions.
