Rajesh Kumar1, H I Amols2, M Lovelock3, S D Sharma1, D Datta1. 1. Radiological Physics and Advisory Division, Bhabha Atomic Research Centre, CTCRS, Mumbai, Maharashtra, India. 2. Department of Medical Physics, Ex-Memorial Sloan Kettering Cancer Centre, New York, USA. 3. Department of Medical Physics, Memorial Sloan Kettering Cancer Centre, New York, USA.
Abstract
AIM: The aim of work is to explore a quick, efficient, and effective patient-specific intensity-modulated radiation therapy (IMRT) quality assurance (QA). MATERIALS AND METHODS: Software tools were developed to extract and analyze the multi-leaf collimator (MLC) leaf positions (LPs) from electronic portal imaging device (EPID) images for Varian C-series machine and TrueBeam, to extract useful data from MLC log file of C-series linear accelerator (LINAC), to extract useful information from the trajectory log binary file of TrueBeam LINAC, to compare LPs derived from EPID images with log file/trajectory log data, and to analyze IMRT treatment files using the MATLAB programming language. The difference in LP determined from the trajectory log and EPID images was proposed for patient-specific QA. RESULTS: It was found that the differences in LP for regular radiation fields generated using stationary leaves are <0.5 mm for all the field sizes while for regular radiation fields generated using the moving leaves are more but <2 mm. The differences in LPs for IMRT field were also determined and found to be <2 mm. CONCLUSIONS: The methodology demonstrated can be used for establishing the accuracy of trajectory log data and for independent routine IMRT QA by generating single number like gamma index to indicate pass or fail of an IMRT treatment plan. The QA indices such as numbers of occurrences of ≥2 mm error in LPS are found more than 5% of total number of occurrences; the dosimetric review of planned treatment is advisable.
AIM: The aim of work is to explore a quick, efficient, and effective patient-specific intensity-modulated radiation therapy (IMRT) quality assurance (QA). MATERIALS AND METHODS: Software tools were developed to extract and analyze the multi-leaf collimator (MLC) leaf positions (LPs) from electronic portal imaging device (EPID) images for Varian C-series machine and TrueBeam, to extract useful data from MLC log file of C-series linear accelerator (LINAC), to extract useful information from the trajectory log binary file of TrueBeam LINAC, to compare LPs derived from EPID images with log file/trajectory log data, and to analyze IMRT treatment files using the MATLAB programming language. The difference in LP determined from the trajectory log and EPID images was proposed for patient-specific QA. RESULTS: It was found that the differences in LP for regular radiation fields generated using stationary leaves are <0.5 mm for all the field sizes while for regular radiation fields generated using the moving leaves are more but <2 mm. The differences in LPs for IMRT field were also determined and found to be <2 mm. CONCLUSIONS: The methodology demonstrated can be used for establishing the accuracy of trajectory log data and for independent routine IMRT QA by generating single number like gamma index to indicate pass or fail of an IMRT treatment plan. The QA indices such as numbers of occurrences of ≥2 mm error in LPS are found more than 5% of total number of occurrences; the dosimetric review of planned treatment is advisable.
Authors: Wui Ann Woon; Paul B Ravindran; Piyasiri Ekayanake; Subramani Vikraman; Siti Amirah; Yivonne Y F Lim; Christopher H S Vun; Jamsari Khalid Journal: Rep Pract Oncol Radiother Date: 2018-08-13
Authors: Michael Barnes; Dennis Pomare; Marcus Doebrich; Therese S Standen; Joshua Wolf; Peter Greer; John Simpson Journal: J Appl Clin Med Phys Date: 2022-06-09 Impact factor: 2.243