title: Quality Assurance Results for a Commercial Radiosurgery System: A Communication.
abstract: The purpose of this communication is to inform the radiosurgery community of quality assurance (QA) results requiring attention in a commercial FDA-approved linac-based cone stereo-tactic radiosurgery (SRS) system. Standard published QA guidelines as per the American Association of Physics in Medicine (AAPM) were followed during the SRS system's commissioning process including end-to-end testing, cone concentricity testing, image transfer verification, and documentation. Several software and hardware deficiencies that were deemed risky were uncovered during the process and QA processes were put in place to mitigate these risks during clinical practice. In particular, the present work focuses on daily cone concentricity testing and commissioning-related findings associated with the software. Cone concentricity/alignment is measured daily using both optical light field inspection, as well as quantitative radiation field tests with the electronic portal imager. In 10 out of 36 clini-cal treatments, adjustments to the cone position had to be made to align the cone with the collimator axis to less than 0.5 mm and on two occasions the pre-adjustment measured offset was 1.0 mm. Software-related errors discovered during commissioning included incorrect transfer of the isocentre in DICOM coordinates, improper handling of non-axial image sets, and complex handling of beam data, especially for multi-target treatments. QA processes were established to mitigate the occurrence of the software errors. With proper QA processes, the reported SRS system complies with tolerances set out in established guidelines. Discussions with the vendor are ongoing to address some of the hardware issues related to cone alignment.
authors.affiliation: Department of Medical Physics, Sunnybrook Odette Cancer Centre, Toronto, ON, Canada Department of Radiation Oncology, University of Toronto, Toronto, ON, Canada Mark.Ruschin@sunnybrook.ca.
authors.forename: Mark
authors.initials: M
authors.lastname: Ruschin
authors.affiliation: Department of Medical Physics, Sunnybrook Odette Cancer Centre, Toronto, ON, Canada Department of Radiation Oncology, University of Toronto, Toronto, ON, Canada.
authors.forename: Alexander
authors.initials: A
authors.lastname: Lightstone
authors.affiliation: Department of Medical Physics, Sunnybrook Odette Cancer Centre, Toronto, ON, Canada Department of Radiation Oncology, University of Toronto, Toronto, ON, Canada.
authors.forename: David
authors.initials: D
authors.lastname: Beachey
authors.affiliation: Department of Medical Physics, Sunnybrook Odette Cancer Centre, Toronto, ON, Canada.
authors.forename: Matt
authors.initials: M
authors.lastname: Wronski
authors.affiliation: Department of Medical Physics, Sunnybrook Odette Cancer Centre, Toronto, ON, Canada.
authors.forename: Steven
authors.initials: S
authors.lastname: Babic
authors.affiliation: Department of Medical Physics, Sunnybrook Odette Cancer Centre, Toronto, ON, Canada Department of Radiation Oncology, University of Toronto, Toronto, ON, Canada.
authors.forename: Collins
authors.initials: C
authors.lastname: Yeboah
authors.affiliation: Department of Medical Physics, Sunnybrook Odette Cancer Centre, Toronto, ON, Canada.
authors.forename: Young
authors.initials: Y
authors.lastname: Lee
authors.affiliation: Department of Radiation Oncology, University of Toronto, Toronto, ON, Canada Department of Radiation Oncology, Sunnybrook Odette Cancer Centre, Toronto, ON, Canada.
authors.forename: Hany
authors.initials: H
authors.lastname: Soliman
authors.affiliation: Department of Radiation Oncology, University of Toronto, Toronto, ON, Canada Department of Radiation Oncology, Sunnybrook Odette Cancer Centre, Toronto, ON, Canada.
authors.forename: Arjun
authors.initials: A
authors.lastname: Sahgal
mesh_terms: D004867:Equipment Design; D006801:Humans; D011785:Quality Assurance, Health Care; D016634:Radiosurgery / Q000379:methods*; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods*; D061106:Radiotherapy Setup Errors; D061089:Radiotherapy, Image-Guided / Q000379:methods*; D012984:Software
keywords: Image-guidance; Radiosurgery; Stereotactic; Stereotactic cones.