Variation of patient imaging doses with scanning parameters for linac-integrated kilovoltage cone beam CT
To evaluate the Elekta kilovoltage CBCT doses and the associated technical protocols with patient dosimetry estimation.Image guidance technique with cone-beam CT (CBCT) in radiation oncology on a daily basis can deliver a significant dose to the patient.To evaluate the patient dose from LINAC-integrated kV cone beam CT imaging in image-guided radiotherapy.CT dose index (CTDI) were measured with PTW TM30009 CT ion chamber in air, in head phantom and body phantom, respectively;with different combinations of tube voltage, current, exposure time per frame, collimator and gantry rotation range.Dose length products (DLP) were subsequently calculated to account for volume integration effects.The CTDI and DLP were also compared to AcQSimTM simulator CT for routine clinical protocols.Both CTDIair and CTDIw depended quadratically on the voltage, while linearly on milliampere x seconds (mAs) settings.It was shown that CTDIw and DLP had very close relationship with the collimator settings and the gantry rotation ranges.Normalized CTDIw for Elekta XVITM CBCT was lower than that of ACQSim simulator CT owing to its pulsed radiation output characteristics.CTDIw can be used to assess the patient dose in CBCT due to its simplicity for measurement and reproducibility.Regular measurement should be performed in QA & QC program.Optimal image parameters should be chosen to reduce patient dose during CBCT.
Cone-beam CT CT dose index dose-length product image-guided radiotherapy
Xiongfei Liao Yunlai Wang Jinyi Lang Pei Wang Jie Li Ruigang Ge Jack Yang
Department of Radiation Oncology,Sichuan Cancer Hospital,55 4th Section Renmin South Road,Chengdu,61 Department of Radiation Oncology,Chinese PLA General Hospital,28 Fuxing Avenue,Beijing,100853,China Department of Radiation Oncology,Monmouth Medical Center,Long Branch,NJ 07740,USA
国内会议
北京
英文
773-781
2016-01-09（万方平台首次上网日期，不代表论文的发表时间）