A comprehensive investigation of the accuracy and reproducibility of a multitarget single isocenter VMAT radiosurgery technique Andrew Thomas, Michael Niebanck, Titania Juang, Zhiheng Wang, and Mark Oldham Citation: Medical Physics 40, 121725 (2013); doi: 10.1118/1.4829518 View online: http://dx.doi.org/10.1118/1.4829518 View Table of Contents: http://scitation.aip.org/content/aapm/journal/medphys/40/12?ver=pdfcov Published by the American Association of Physicists in Medicine Articles you may be interested in Investigating the accuracy of microstereotactic-body-radiotherapy utilizing anatomically accurate 3D printed rodent-morphic dosimeters Med. Phys. 42, 846 (2015); 10.1118/1.4905489 Effect of dosimeter type for commissioning small photon beams on calculated dose distribution in stereotactic radiosurgery Med. Phys. 41, 092101 (2014); 10.1118/1.4892176 Increasing dose gradient and uniformity in small fields using modulation: Theory and prototypes for cone-based stereotactic radiosurgery Med. Phys. 41, 051706 (2014); 10.1118/1.4870380 Verification of Gamma Knife extend system based fractionated treatment planning using EBT2 film Med. Phys. 40, 122104 (2013); 10.1118/1.4832138 On the implementation of a recently proposed dosimetric formalism to a robotic radiosurgery system Med. Phys. 37, 2369 (2010); 10.1118/1.3404289
A comprehensive investigation of the accuracy and reproducibility of a multitarget single isocenter VMAT radiosurgery technique Andrew Thomas, Michael Niebanck, Titania Juang, Zhiheng Wang, and Mark Oldhama) Duke University Medical Center, Durham, North Carolina 27710
(Received 25 May 2013; revised 24 October 2013; accepted for publication 26 October 2013; published 26 November 2013) Purpose: Recent trends in stereotactic radiosurgery use multifocal volumetric modulated arc therapy (VMAT) plans to simultaneously treat several distinct targets. Conventional verification often involves low resolution measurements in a single plane, a cylinder, or intersecting planes of diodes or ion chambers. This work presents an investigation into the consistency and reproducibility of this new treatment technique using a comprehensive commissioned high-resolution 3D dosimetry system R /Optical-CT). (PRESAGE Methods: A complex VMAT plan consisting of a single isocenter but five separate targets was R dosimetry insert of created in Eclipse for a head phantom containing a cylindrical PRESAGE 11 cm diameter and height. The plan contained five VMAT arcs delivering target doses from 12 to 20 Gy. The treatment was delivered to four dosimeters positioned in the head phantom and repeated four times, yielding four separate 3D dosimetry verifications. Each delivery was completely independent and was given after image guided radiation therapy (IGRT) positioning using Brainlab ExacTrac and cone beam computed tomography. A final delivery was given R to a modified insert containing a pin-point ion chamber enabling calibration of PRESAGE 3D data to dose. Dosimetric data were read out in an optical-CT scanner. Consistency and reproducibility of the treatment technique (including IGRT setup) was investigated by comparing the dose distributions in the four inserts, and with the predicted treatment planning system distribution. Results: Dose distributions from the four dosimeters were registered and analyzed to determine the mean and standard deviation at all points throughout the dosimeters. A dose standard deviation of
A comprehensive investigation of the accuracy and reproducibility of a multitarget single isocenter VMAT radiosurgery technique Andrew Thomas, Michael Niebanck, Titania Juang, Zhiheng Wang, and Mark Oldhama) Duke University Medical Center, Durham, North Carolina 27710
(Received 25 May 2013; revised 24 October 2013; accepted for publication 26 October 2013; published 26 November 2013) Purpose: Recent trends in stereotactic radiosurgery use multifocal volumetric modulated arc therapy (VMAT) plans to simultaneously treat several distinct targets. Conventional verification often involves low resolution measurements in a single plane, a cylinder, or intersecting planes of diodes or ion chambers. This work presents an investigation into the consistency and reproducibility of this new treatment technique using a comprehensive commissioned high-resolution 3D dosimetry system R /Optical-CT). (PRESAGE Methods: A complex VMAT plan consisting of a single isocenter but five separate targets was R dosimetry insert of created in Eclipse for a head phantom containing a cylindrical PRESAGE 11 cm diameter and height. The plan contained five VMAT arcs delivering target doses from 12 to 20 Gy. The treatment was delivered to four dosimeters positioned in the head phantom and repeated four times, yielding four separate 3D dosimetry verifications. Each delivery was completely independent and was given after image guided radiation therapy (IGRT) positioning using Brainlab ExacTrac and cone beam computed tomography. A final delivery was given R to a modified insert containing a pin-point ion chamber enabling calibration of PRESAGE 3D data to dose. Dosimetric data were read out in an optical-CT scanner. Consistency and reproducibility of the treatment technique (including IGRT setup) was investigated by comparing the dose distributions in the four inserts, and with the predicted treatment planning system distribution. Results: Dose distributions from the four dosimeters were registered and analyzed to determine the mean and standard deviation at all points throughout the dosimeters. A dose standard deviation of
