1. Department of Radiation Oncology, Peking Union Medical College Hospital, Beijing 100730, China丨
2. OUR United Corporation, Xi’an Shaanxi 710016, China丨
3. Varian Medical System (China) Co., Ltd, Beijing 100176, China
Abstract:Objective To verify the representative beam data (RBD) of Halcyon v2.0 accelerator by using three-dimensional water
tank and analyze the differences, so as to verify the accuracy of RBD of Halcyon v2.0 accelerator. Methods The measurement was
based on Blue Phantom2 three-dimensional water tank and Accept (v7.2) software. CC13 ionization chamber was used to measure
the percentile depth curve. PFD and SFD were used to measure the off-axis ratio curve, and CC13 and SFD were used to measure the
output factors of large and small fields respectively, which were connected by daisy-chain method. The deviation between RBD and
actual measurement data (MeasData)丨 between MeasData and calculated data (CalcData) of treatment planning system were compared
by Python and MATLAB self-designed program. Results For the percentage depth dose between RBD and MeasData, as well as
MeasData and CalcData, the gamma pass rates under the standard of 1 mm/1%, 2 mm/2%, 3 mm/3% were all over 99%. For the offaxis
ratio, the average pass rate between RBD and MeasData was 93.54%±5.42% at 1 mm/1%, 99.43%±1.16% at 2 mm/2%, 100% at
3 mm/3%, 99.07%±1.35% at 1 mm/1%, 100% at 2 mm/2% and 3 mm/3%. For the field output factor, the deviation of the field output
factor data was between 1% and 3% when the field size was less than 2 cm×2 cm, and the deviation of the field output factor data was
less than 1% when the field size was greater than or equal to 2 cm×2 cm. Conclusion The RBD can be verified completely by using
three-dimensional water tank and suitable detector. The measurement results obtained in this study meet the requirements of clinical
use. This method can be used as a reference for data verification of other accelerators.