title: Initial experience with TrueBeam trajectory log files for radiation therapy delivery verification.
abstract: OBJECTIVE
  Traditionally, initial and weekly chart checks involve checking various parameters in the treatment management system against the expected treatment parameters and machine settings. This process is time-consuming and labor intensive. We explore utilizing the Varian TrueBeam log files (Varian Medical System, Palo Alto, CA), which contain the complete delivery parameters for an end-to-end verification of daily patient treatments.
  
  
  METHODS
  An in-house software tool for 3-dimensional (3D) conformal therapy, enhanced dynamic wedge delivery, intensity modulated radiation therapy (IMRT), volumetric modulated radiation therapy, flattening filter-free mode, and electron therapy treatment verification was developed. The software reads the Varian TrueBeam log files, extracts the delivered parameters, and compares them against the original treatment planning data. In addition to providing an end-to-end data transfer integrity check, the tool also verifies the accuracy of treatment deliveries. This is performed as part of the initial chart check for IMRT plans and after first fraction for the 3D plans. The software was validated for consistency and accuracy for IMRT and 3D fields.
  
  
  RESULTS
  Based on the validation results the accuracy of MLC, jaw and gantry positions were well within the expected values. The patient quality assurance results for 127 IMRT patients and 51 conventional fields were within 0.25 mm for multileaf collimator positions, 0.3 degree for gantry angles, 0.13 monitor units for monitor unit delivery accuracy, and 1 mm for jaw positions. The delivered dose rates for the flattening filter-free modes were within 1% of the planned dose rates.
  
  
  CONCLUSIONS
  The end-to-end data transfer check using TrueBeam log files and the treatment delivery parameter accuracy check provides an efficient, reliable beam parameter check process for various radiation delivery techniques.
authors.affiliation: Department of Radiation Oncology, Washington University School of Medicine, 4921 Parkview Place, St Louis, Missouri.
authors.forename: Baozhou
authors.initials: B
authors.lastname: Sun
authors.affiliation: Department of Radiation Oncology, Scott and White Clinic, Temple, Texas.
authors.forename: Dharanipathy
authors.initials: D
authors.lastname: Rangaraj
authors.affiliation: Department of Radiation Oncology, Scott and White Clinic, Temple, Texas.
authors.forename: Geethpriya
authors.initials: G
authors.lastname: Palaniswaamy
authors.affiliation: Department of Radiation Oncology, Washington University School of Medicine, 4921 Parkview Place, St Louis, Missouri.
authors.forename: Sridhar
authors.initials: S
authors.lastname: Yaddanapudi
authors.affiliation: Department of Radiation Oncology, Washington University School of Medicine, 4921 Parkview Place, St Louis, Missouri.
authors.forename: Omar
authors.initials: O
authors.lastname: Wooten
authors.affiliation: Department of Radiation Oncology, Washington University School of Medicine, 4921 Parkview Place, St Louis, Missouri.
authors.forename: Deshan
authors.initials: D
authors.lastname: Yang
authors.affiliation: Department of Radiation Oncology, Washington University School of Medicine, 4921 Parkview Place, St Louis, Missouri.
authors.forename: Sasa
authors.initials: S
authors.lastname: Mutic
authors.affiliation: Department of Radiation Oncology, Washington University School of Medicine, 4921 Parkview Place, St Louis, Missouri. Electronic address: lsantanam@radonc.wustl.edu.
authors.forename: Lakshmi
authors.initials: L
authors.lastname: Santanam