Abstract：Objective To investigate and compare the effects of dose attenuation of four different treatment couches on VitalBeam
accelerator. Methods The center of the solid water phantom was aligned with the VitalBeam accelerator iso center. Two kinds of
couch from CIVCO and Qfix were placed on the solid water phantom respectively. The longitudinal center axis of the couch was
aligned with the middle laser line. A thimble chamber was utilized to measure the absolute dose in the phantom. Under VitalBeam’s
6 MV, 10 MV, 6 FFF and 10 FFF four-level photon beam energy, 10 cm×10 cm and 5 cm×5 cm emission fields were selected,
and the frame angle was 0°~80° (measured at an interval of 10°). The dose with couch and without couch were measured and the
attenuation coefficients of each couch at different gantry angles were compared. Results Under the four different photon energies
modes and 10 cm×10 cm and 5 cm×5 cm field sizes of VitalBeam accelerator, the attenuation coefficients of CIVCO carbon couch
were 2.10%~8.19%. The attenuation coefficients of CIVCO Kevlar couch were 2.73%~8.97%. The attenuation coefficients of Qfix
Calypso couch was 1.49%~6.92%. The attenuation factor of Qfix KUTI couch were 1.92%~7.79%, and all attenuation values were
between 0°~70° and increase with the increase of incident angle. Conclusion The attenuation coefficients of most of the incident
angles of the four couches were more than 2%, and all the couch plates reach their maximum attenuations at oblique incidence of 70°.
The effect of accelerator treatment couch on dose attenuation should be considered in the design of clinical treatment plan, and the
corresponding couch model should be established for different treatment couch.
蓝茂英，杨波，许文伟，吴朱峰，钟振东，伍锐，刘香林，范颖天，孙建聪. VitalBeam加速器四种不同治疗床板的剂量衰减特性测量与分析[J]. 中国医疗设备, 2022, 37(4): 51-54.
LAN Maoying, YANG Bo, XU Wenwei, WU Zhufeng, ZHONG Zhendong, WU Rui, LIU Xianglin,
FAN Yingtian, SUN Jiancong. Measurement and Analysis of Dose Attenuation Characteristics of
Four Different Treatment Couch for VitalBeam Accelerator. China Medical Devices, 2022, 37(4): 51-54.
