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Title: Accuracy evaluation of the optical surface monitoring system on EDGE linear accelerator in a phantom study

Abstract

Frameless stereotactic radiosurgery (SRS) requires dedicated systems to monitor the patient position during the treatment to avoid target underdosage due to involuntary shift. The optical surface monitoring system (OSMS) is here evaluated in a phantom-based study. The new EDGE linear accelerator from Varian (Varian, Palo Alto, CA) integrates, for cranial lesions, the common cone beam computed tomography (CBCT) and kV-MV portal images to the optical surface monitoring system (OSMS), a device able to detect real-time patient's face movements in all 6 couch axes (vertical, longitudinal, lateral, rotation along the vertical axis, pitch, and roll). We have evaluated the OSMS imaging capability in checking the phantoms' position and monitoring its motion. With this aim, a home-made cranial phantom was developed to evaluate the OSMS accuracy in 4 different experiments: (1) comparison with CBCT in isocenter location, (2) capability to recognize predefined shifts up to 2° or 3 cm, (3) evaluation at different couch angles, (4) ability to properly reconstruct the surface when the linac gantry visually block one of the cameras. The OSMS system showed, with a phantom, to be accurate for positioning in respect to the CBCT imaging system with differences of 0.6 ± 0.3 mm for linear vector displacement,more » with a maximum rotational inaccuracy of 0.3°. OSMS presented an accuracy of 0.3 mm for displacement up to 1 cm and 1°, and 0.5 mm for larger displacements. Different couch angles (45° and 90°) induced a mean vector uncertainty < 0.4 mm. Coverage of 1 camera produced an uncertainty < 0.5 mm. Translations and rotations of a phantom can be accurately detect with the optical surface detector system.« less

Authors:
; ; ; ; ;
Publication Date:
OSTI Identifier:
22577880
Resource Type:
Journal Article
Resource Relation:
Journal Name: Medical Dosimetry; Journal Volume: 41; Journal Issue: 2; Other Information: Copyright (c) 2016 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
61 RADIATION PROTECTION AND DOSIMETRY; 62 RADIOLOGY AND NUCLEAR MEDICINE; ACCURACY; BEAM MONITORS; BEAM POSITION; BIOMEDICAL RADIOGRAPHY; CAMERAS; COMPUTERIZED TOMOGRAPHY; LINEAR ACCELERATORS; PATIENTS; PHANTOMS; RADIOTHERAPY; SURGERY

Citation Formats

Mancosu, Pietro, Fogliata, Antonella, E-mail: Antonella.Fogliata@humanitas.it, Stravato, Antonella, Tomatis, Stefano, Cozzi, Luca, and Scorsetti, Marta. Accuracy evaluation of the optical surface monitoring system on EDGE linear accelerator in a phantom study. United States: N. p., 2016. Web. doi:10.1016/J.MEDDOS.2015.12.003.
Mancosu, Pietro, Fogliata, Antonella, E-mail: Antonella.Fogliata@humanitas.it, Stravato, Antonella, Tomatis, Stefano, Cozzi, Luca, & Scorsetti, Marta. Accuracy evaluation of the optical surface monitoring system on EDGE linear accelerator in a phantom study. United States. doi:10.1016/J.MEDDOS.2015.12.003.
Mancosu, Pietro, Fogliata, Antonella, E-mail: Antonella.Fogliata@humanitas.it, Stravato, Antonella, Tomatis, Stefano, Cozzi, Luca, and Scorsetti, Marta. Fri . "Accuracy evaluation of the optical surface monitoring system on EDGE linear accelerator in a phantom study". United States. doi:10.1016/J.MEDDOS.2015.12.003.
@article{osti_22577880,
title = {Accuracy evaluation of the optical surface monitoring system on EDGE linear accelerator in a phantom study},
author = {Mancosu, Pietro and Fogliata, Antonella, E-mail: Antonella.Fogliata@humanitas.it and Stravato, Antonella and Tomatis, Stefano and Cozzi, Luca and Scorsetti, Marta},
abstractNote = {Frameless stereotactic radiosurgery (SRS) requires dedicated systems to monitor the patient position during the treatment to avoid target underdosage due to involuntary shift. The optical surface monitoring system (OSMS) is here evaluated in a phantom-based study. The new EDGE linear accelerator from Varian (Varian, Palo Alto, CA) integrates, for cranial lesions, the common cone beam computed tomography (CBCT) and kV-MV portal images to the optical surface monitoring system (OSMS), a device able to detect real-time patient's face movements in all 6 couch axes (vertical, longitudinal, lateral, rotation along the vertical axis, pitch, and roll). We have evaluated the OSMS imaging capability in checking the phantoms' position and monitoring its motion. With this aim, a home-made cranial phantom was developed to evaluate the OSMS accuracy in 4 different experiments: (1) comparison with CBCT in isocenter location, (2) capability to recognize predefined shifts up to 2° or 3 cm, (3) evaluation at different couch angles, (4) ability to properly reconstruct the surface when the linac gantry visually block one of the cameras. The OSMS system showed, with a phantom, to be accurate for positioning in respect to the CBCT imaging system with differences of 0.6 ± 0.3 mm for linear vector displacement, with a maximum rotational inaccuracy of 0.3°. OSMS presented an accuracy of 0.3 mm for displacement up to 1 cm and 1°, and 0.5 mm for larger displacements. Different couch angles (45° and 90°) induced a mean vector uncertainty < 0.4 mm. Coverage of 1 camera produced an uncertainty < 0.5 mm. Translations and rotations of a phantom can be accurately detect with the optical surface detector system.},
doi = {10.1016/J.MEDDOS.2015.12.003},
journal = {Medical Dosimetry},
number = 2,
volume = 41,
place = {United States},
year = {Fri Jul 01 00:00:00 EDT 2016},
month = {Fri Jul 01 00:00:00 EDT 2016}
}