Online dose reconstruction for tracked volumetric arc therapy: Real-time implementation and offline quality assurance for prostate SBRT
File(s)
Published version
Author(s)
Type
Journal Article
Abstract
Purpose
Firstly, this study provides a real‐time implementation of online dose reconstruction for tracked volumetric arc therapy (VMAT). Secondly, this study describes a novel offline quality assurance tool, based on commercial dose calculation algorithms.
Methods
Online dose reconstruction for VMAT is a computationally challenging task in terms of computer memory usage and calculation speed. To potentially reduce the amount of memory used, we analyzed the impact of beam angle sampling for dose calculation on the accuracy of the dose distribution. To establish the performance of the method, we planned two single‐arc VMAT prostate stereotactic body radiation therapy cases for delivery with dynamic MLC tracking. For quality assurance of our online dose reconstruction method we have also developed a stand‐alone offline dose reconstruction tool, which utilizes the RayStation treatment planning system to calculate dose.
Results
For the online reconstructed dose distributions of the tracked deliveries, we could establish strong resemblance for 72 and 36 beam co‐planar equidistant beam samples with less than 1.2% deviation for the assessed dose‐volume indicators (clinical target volume D98 and D2, and rectum D2). We could achieve average runtimes of 28–31 ms per reported MLC aperture for both dose computation and accumulation, meeting our real‐time requirement. To cross‐validate the offline tool, we have compared the planned dose to the offline reconstructed dose for static deliveries and found excellent agreement (3%/3 mm global gamma passing rates of 99.8%–100%).
Conclusion
Being able to reconstruct dose during delivery enables online quality assurance and online replanning strategies for VMAT. The offline quality assurance tool provides the means to validate novel online dose reconstruction applications using a commercial dose calculation engine.
Firstly, this study provides a real‐time implementation of online dose reconstruction for tracked volumetric arc therapy (VMAT). Secondly, this study describes a novel offline quality assurance tool, based on commercial dose calculation algorithms.
Methods
Online dose reconstruction for VMAT is a computationally challenging task in terms of computer memory usage and calculation speed. To potentially reduce the amount of memory used, we analyzed the impact of beam angle sampling for dose calculation on the accuracy of the dose distribution. To establish the performance of the method, we planned two single‐arc VMAT prostate stereotactic body radiation therapy cases for delivery with dynamic MLC tracking. For quality assurance of our online dose reconstruction method we have also developed a stand‐alone offline dose reconstruction tool, which utilizes the RayStation treatment planning system to calculate dose.
Results
For the online reconstructed dose distributions of the tracked deliveries, we could establish strong resemblance for 72 and 36 beam co‐planar equidistant beam samples with less than 1.2% deviation for the assessed dose‐volume indicators (clinical target volume D98 and D2, and rectum D2). We could achieve average runtimes of 28–31 ms per reported MLC aperture for both dose computation and accumulation, meeting our real‐time requirement. To cross‐validate the offline tool, we have compared the planned dose to the offline reconstructed dose for static deliveries and found excellent agreement (3%/3 mm global gamma passing rates of 99.8%–100%).
Conclusion
Being able to reconstruct dose during delivery enables online quality assurance and online replanning strategies for VMAT. The offline quality assurance tool provides the means to validate novel online dose reconstruction applications using a commercial dose calculation engine.
Date Issued
2017-11-01
Date Acceptance
2017-08-10
Citation
Medical Physics, 2017, 44 (11), pp.5997-6007
ISSN
0094-2405
Publisher
Wiley
Start Page
5997
End Page
6007
Journal / Book Title
Medical Physics
Volume
44
Issue
11
Copyright Statement
© 2017 The Authors. Medical Physics published by Wiley Periodicals, Inc. on behalf of American Association of Physicists in Medicine.
This is an open access article under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
This is an open access article under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
Identifier
http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000414970800042&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=1ba7043ffcc86c417c072aa74d649202
Subjects
Science & Technology
Life Sciences & Biomedicine
Radiology, Nuclear Medicine & Medical Imaging
MLC tracking
online dose reconstruction
online quality assurance
volumetric arc therapy
MLC TRACKING
MODULATED ARC
VMAT QA
MOTION
IMRT
PERFORMANCE
Publication Status
Published
Date Publish Online
2017-08-20