The dose delivery effect of the different Beam ON interval in FFF SBRT: TrueBEAM

13th South-East Asian Congress of Medical Physics 2015

物理学;医药卫生

Tawonwong, T.^1 ; Suriyapee, S.^2 ; Oonsiri, S.^1 ; Sanghangthum, T.^1 ; Oonsiri, P.^1

Department of Radiology, King Chulalongkom Memorial Hospital, BKK, Thailand^1

Department of Radiology, Faculty of Medicine, Chulalongkom University, BKK, Thailand^2

关键词: Breath-hold treatments;    Dose measurement;    Flattening filter free;    Free breathing;    Gamma analysis;    Plan verifications;    Stereotactic body radiation therapy;    Treatment planning;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/694/1/012026/pdf
DOI  :  10.1088/1742-6596/694/1/012026

学科分类：卫生学

来源: IOP

【 摘 要 】

The purpose of this study is to determine the dose delivery effect of the different Beam ON interval in Flattening Filter Free Stereotactic Body Radiation Therapy (FFF-SBRT). The three 10MV-FFF SBRT plans (2 half rotating Rapid Arc, 9 to10 Gray/Fraction) were selected and irradiated in three different intervals (100%, 50% and 25%) using the RPM gating system. The plan verification was performed by the ArcCHECK for gamma analysis and the ionization chamber for point dose measurement. The dose delivery time of each interval were observed. For gamma analysis (2%&2mm criteria), the average percent pass of all plans for 100%, 50% and 25% intervals were 86.1±3.3%, 86.0±3.0% and 86.1±3.3%, respectively. For point dose measurement, the average ratios of each interval to the treatment planning were 1.012±0.015, 1.011±0.014 and 1.011±0.013 for 100%, 50% and 25% interval, respectively. The average dose delivery time was increasing from 74.3±5.0 second for 100% interval to 154.3±12.6 and 347.9±20.3 second for 50% and 25% interval, respectively. The same quality of the dose delivery from different Beam ON intervals in FFF-SBRT by TrueBEAM was illustrated. While the 100% interval represents the breath-hold treatment technique, the differences for the free-breathing using RPM gating system can be treated confidently.