title: Implementation and validation of a commercial portal dosimetry software for intensity-modulated radiation therapy pre-treatment verification.
abstract: Electronic portal imaging devices (EPIDs) are extensively used for obtaining dosimetric information of pre-treatment field verification and in-vivo dosimetry for intensity-modulated radiotherapy (IMRT). In the present study, we have implemented the newly developed portal dosimetry software using independent dose prediction algorithm EPIDose(™) and evaluated this new tool for the pre-treatment IMRT plan quality assurance of Whole Pelvis with Simultaneous Integrated Boost (WP-SIB-IMRT) of prostate cases by comparing with routine two-dimensional (2D) array detector system (MapCHECK(™)). We have investigated 104 split fields using γ -distributions in terms of predefined γ frequency parameters. The mean γ values are found to be 0.42 (SD: 0.06) and 0.44 (SD: 0.06) for the EPIDose and MapCHECK(™), respectively. The average γ∆ for EPIDose and MapCHECK(™) are found as 0.51 (SD: 0.06) and 0.53 (SD: 0.07), respectively. Furthermore, the percentage of points with γ < 1, γ < 1.5, and γ > 2 are 97.4%, 99.3%, and 0.56%, respectively for EPIDose and 96.4%, 99.0% and 0.62% for MapCHECK(™). Based on our results obtained with EPIDose and strong agreement with MapCHECK(™), we may conclude that the EPIDose portal dosimetry system has been successfully implemented and validated with our routine 2D array detector.
authors.affiliation: Department of Medical Physics, University Hospital, Udine - 33100, India.
authors.forename: C
authors.initials: C
authors.lastname: Varatharaj
authors.forename: Eugenia
authors.initials: E
authors.lastname: Moretti
authors.forename: M
authors.initials: M
authors.lastname: Ravikumar
authors.forename: Maria Rosa
authors.initials: MR
authors.lastname: Malisan
authors.forename: Sanjay S
authors.initials: SS
authors.lastname: Supe
authors.forename: Renato
authors.initials: R
authors.lastname: Padovani