A study on investigating the delivery parameter error effect on the variation of patient quality assurance during RapidArc treatment. Issue 3 (8th February 2013)

• Record Type: Journal Article
• Authors: Peng, Jiayuan; Zhang, Zhen; Zhou, Lijun; Zhao, Jinfang; Wang, Jiazhou; Kong, Lin; Hu, Weigang
• Is Part Of: Medical physics. Volume 40:Issue 3(2013)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2013-02-08
• Subjects: Quality assurance in radiotherapy -- Cancer -- Dose‐volume analysis; cancer -- dosimetry -- radiation therapy -- tumours; RapidArc -- delivery parameter error (DPE) -- quality assurance (QA) -- head‐and‐neck cancer -- dynalog files; Radiation therapy; Multileaf collimators -- Dosimetry -- Cancer -- Error analysis -- Quality assurance -- Intensity modulated radiation therapy -- Linear accelerators -- Medical treatment planning -- Anatomy -- Medical accelerators; Medical physics -- Periodicals; Medical physics; Geneeskunde; Natuurkunde; Toepassingen; Biophysics; Periodicals; Periodicals; Electronic journals; 610.153
• DOI: 10.1118/1.4789631
• Languages: English
• ISSNs: 0094-2405

Abstract

Abstract : Purpose: : The purpose of this study is to evaluate delivery parameter errors (DPEs) and their impact on clinical dose variation with the Varian RapidArc technique. Methods: : The dynalog files of 16 head‐and‐neck patients were retrospectively analyzed to characterize three RapidArc DPEs: dose MU, gantry angle, and MLC gap errors. A total of 64 reconstructed plans were created by creating four variants of each of the original 16 plans (three with the DPEs applied individually and one with the three DPEs combined). These reconstructed plans were compared to the original plans to evaluate the impact of the DPEs on the clinical dose distribution. Results: : The mean dose MU, gantry angle, and MLC gap error for all patients were 0.00 ± 0.00 MU, −0.36 ± 0.03°, and 0.00 ± 0.01 mm, respectively. The DPEs had no obvious dosimetric impact on any of the studied dosimetric endpoints except the parotid dose. The gantry angle error, MLC gap error, and combined DPEs changed the parotid Dmean (mean dose) and parotid V30 (volume receiving at least 30 Gy) by 1%–2%. Conclusions: : It is feasible to use dose distributions reconstructed from dynalog file data as a quality assurance tool. The dose MU, gantry angle, and MLC errors have only minor effects on the accuracy of the delivered dose.