title: An institutional experience of quality assurance of a treatment planning system on photon beam.
abstract: OBJECTIVE
  The purpose of the present study is to show the application of the IAEA TRS-430 QA procedures of Eclipse™v7.5 TPS for photon energies. In addition, the trends of the deviations found in the conducted tests were determined.
  
  
  BACKGROUND
  In the past, the lack of complete TPS QA procedures led to some serious accidents. So, QA in the radiotherapy treatment planning process is essential for determination of accuracy in the radiotherapy process and avoidance of treatment errors.
  
  
  METHODS
  The calculations of TPS and measurements of irradiations of the treatment device were compared in the study. As a result, the local dose deviation values (δ 1: central beam axis, δ 2: penumbra and build up region, δ 3: inside field, δ 4: outside beam edges, δ 50-90: beam fringe, RW50: radiological width) and their confidence limit values (including systematic and random errors) were obtained.
  
  
  RESULTS
  The confidence limit values of δ 4 were detected to increase with expanding field size. The values of δ 1 and δ 3 of hard wedge were larger than open fields. The values of δ 2 and δ 50-90 of the inhomogeneity effect test were larger, especially than other tests of this study. The average deviation was showed to increase with the rise of the wedge angle. The values of δ 3 and δ 4 of lung irradiation were outside tolerance.
  
  
  CONCLUSIONS
  The QA of TPS was done and it was found that there were no reservations in its use in patient treatment. The trend of the deviations is shown.
authors.affiliation: Department of Radiation Oncology, Cumhuriyet University, Faculty of Medicine, TR-58140 Sivas, Turkey.
authors.forename: Yıldıray
authors.initials: Y
authors.lastname: Ozgüven
authors.affiliation: Department of Radiation Oncology, Erciyes University, Faculty of Medicine, TR-38039 Kayseri, Turkey.
authors.forename: Kadir
authors.initials: K
authors.lastname: Yaray
authors.affiliation: Department of Radiation Oncology, Medicana Hospital, TR-34520 Istanbul, Turkey.
authors.forename: Fadime
authors.initials: F
authors.lastname: Alkaya
authors.affiliation: Department of Radiation Oncology, Cumhuriyet University, Faculty of Medicine, TR-58140 Sivas, Turkey.
authors.forename: Birsen
authors.initials: B
authors.lastname: Yücel
authors.affiliation: Department of Radiation Oncology, Erciyes University, Faculty of Medicine, TR-38039 Kayseri, Turkey.
authors.forename: Serdar
authors.initials: S
authors.lastname: Soyuer
keywords: Confidence limit; Local dose deviation; Photon beam; Quality assurance; Treatment planning system