title: Passive breath gating equipment for cone beam CT-guided RapidArc gastric cancer treatments.
abstract: OBJECTIVE
  To report preliminary results of passive breath gating (PBG) equipment for cone-beam CT image-guided gated RapidArc gastric cancer treatments.
  
  
  METHODS
  Home-developed PBG equipment integrated with the real-time position management system (RPM) for passive patient breath hold was used in CT simulation, online partial breath hold (PBH) CBCT acquisition, and breath-hold gating (BHG) RapidArc delivery. The treatment was discontinuously delivered with beam on during BH and beam off for free breathing (FB). Pretreatment verification PBH CBCT was obtained with the PBG-RPM system. Additionally, the reproducibility of the gating accuracy was evaluated.
  
  
  RESULTS
  A total of 375 fractions of breath-hold gating RapidArc treatments were successfully delivered and 233 PBH CBCTs were available for analysis. The PBH CBCT images were acquired with 2-3 breath holds and 1-2 FB breaks. The imaging time was the same for PBH CBCT and conventional FB CBCT (60s). Compared to FB CBCT, the motion artifacts seen in PBH CBCT images were remarkably reduced. The average BHG RapidArc delivery time was 103 s for one 270-degree arc and 269 s for two full arcs.
  
  
  CONCLUSIONS
  The PBG-RPM based PBH CBCT verification and BHG RapidArc delivery was successfully implemented clinically. The BHG RapidArc treatment was accomplished using a conventional RapidArc machine with high delivery efficiency.
authors.affiliation: Department of Radiation Oncology, Fudan University Shanghai Cancer Center, China; Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, China.
authors.forename: Weigang
authors.initials: W
authors.lastname: Hu
authors.affiliation: Department of Radiation Oncology, Fudan University Shanghai Cancer Center, China; Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, China.
authors.forename: Guichao
authors.initials: G
authors.lastname: Li
authors.affiliation: Department of Radiation Oncology, Swedish Cancer Institute, Seattle, USA.
authors.forename: Jinsong
authors.initials: J
authors.lastname: Ye
authors.affiliation: Department of Radiation Oncology, Fudan University Shanghai Cancer Center, China; Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, China.
authors.forename: Jiazhou
authors.initials: J
authors.lastname: Wang
authors.affiliation: Department of Radiation Oncology, Fudan University Shanghai Cancer Center, China; Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, China.
authors.forename: Jiayuan
authors.initials: J
authors.lastname: Peng
authors.affiliation: Department of Radiation Oncology, Fudan University Shanghai Cancer Center, China; Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, China.
authors.forename: Min
authors.initials: M
authors.lastname: Gong
authors.affiliation: Department of Radiation Oncology, Fudan University Shanghai Cancer Center, China; Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, China.
authors.forename: Xiaoli
authors.initials: X
authors.lastname: Yu
authors.affiliation: Department of Radiation Oncology, University of Miami - Miller School of Medicine, Miami, USA.
authors.forename: Matthew T
authors.initials: MT
authors.lastname: Studentski
authors.affiliation: Department of Radiation Oncology, Thomas Jefferson University, Philadelphia, USA.
authors.forename: Ying
authors.initials: Y
authors.lastname: Xiao
authors.affiliation: Department of Radiation Oncology, Fudan University Shanghai Cancer Center, China; Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, China. Electronic address: zhenzhang6@gmail.com.
authors.forename: Zhen
authors.initials: Z
authors.lastname: Zhang
mesh_terms: D062485:Breath Holding; D054893:Cone-Beam Computed Tomography / Q000295:instrumentation* / Q000379:methods; D006801:Humans; D019047:Phantoms, Imaging; D061089:Radiotherapy, Image-Guided / Q000379:methods; D015203:Reproducibility of Results; D013274:Stomach Neoplasms / Q000532:radiotherapy*
keywords: Breath-hold gated treatment; CBCT; RapidArc