Verification and Correction of Positioning Deviation in Radiotherapy with
Cone Beam CT and HexaPOD Treatment Couch
LIU Lingling1,2,3, FEI Zhenle4, CUI Xiangli1,3, SUN Ruixia1,3 LI Jie1,3, WANG Hongzhi1,2,3
1. Institute of Health and Medical Technology (Anhui Province Key Laboratory of Medical Physics and Technology), Hefei Institutes
of Physical Science, Chinese Academy of Sciences, Hefei Anhui 230031, China; 2. Science Island Branch, Graduate School of
USTC, Hefei Anhui 230026, China; 3. Hefei Cancer Hospital, Chinese Academy of Sciences, Hefei Anhui 230031, China; 4. Cancer
Diagnosis and Treatment Center, No.901 Hospital of PLA Joint Logistic Support Force, Hefei Anhui 230031, China
Abstract：Objective To explore how to use cone beam computed tomography (CBCT) to verify the magnitude of position deviation
of radiotherapy technician and the ability and stability of the HexaPOD treatment couch to correct the errors, so as to provide
clinical reference data. Methods In a retrospective analysis of 340 patients with tumors at different sites confirmed by imaging and
pathology in our hospital in the period from June 2018 to June 2019, the position deviation data of each patient after the initial scan
of CBCT were collected to determine the magnitude of position deviation in different parts of the human body. In addition,
18 special cases with more stringent positioning requirements were selected, of which the deviation corresponding to positions
after initial positioning and after correction of HexaPOD treatment couch, and before the second treatment fraction were recorded.
These data were used to assess the capability of CBCT and HexaPOD treatment couch to correct for the position deviation, and to
confirm the need for verification between treatment fractions. Results The position deviation for head and neck were significantly
smaller than other parts (P<0.05). As regards the 18 studied special cases, all initial position deviation were substantially reduced
upon corrections, with statistical significance (P<0.05) in the translational directions of x, y, and z and rotational directions of Rx and
Rz. However, after corrections of initial position deviation, these devotion would become significantly (P<0.05) larger again after
the first treatment fraction due to human errors. The residual translational and rotational after each correction through CBCT were
consistent, in that no statistically significant differences were observed (P>0.05). All translational and rotational position deviation
after corrections were small, which reached the sub-millimeter and sub-degree levels, respectively. Conclusion Position deviation in
all directions were reduced with the help of CBCT and HexaPOD treatment couch. Further corrections through CBCT scans between
treatment fractions are recommended.
刘苓苓1,2,3，费振乐4，崔相利1,3，孙瑞霞1,3，李洁1,3，王宏志1,2,3. 锥形束CT结合六维床HexaPOD验证及纠正放疗中摆位偏差的研究[J]. 中国医疗设备, 2022, 37(4): 19-22.
LIU Lingling1,2,3, FEI Zhenle4, CUI Xiangli1,3, SUN Ruixia1,3 LI Jie1,3, WANG Hongzhi1,2,3. Verification and Correction of Positioning Deviation in Radiotherapy with
Cone Beam CT and HexaPOD Treatment Couch. China Medical Devices, 2022, 37(4): 19-22.
