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Title: Beam commissioning and measurements validating the beam model in a new TPS that converts helical tomotherapy plans to step-and-shoot IMRT plans

Abstract

Purpose: A new type of treatment planning system called SHAREPLAN has been studied, which enables the transfer of treatment plans generated for helical tomotherapy delivery to plans that can be delivered on C-arm linacs. The purpose is to ensure continuous patient treatment during periods of unscheduled downtime for the TomoTherapy unit, particularly in clinics without a backup unit. The purpose of this work was to verify that the plans generated in this novel planning system are deliverable and accurate. The work consists primarily of beam commissioning, verification of the beam model, and measurements verifying that generated plans are deliverable with sufficient accuracy. Methods: The beam commissioning process involves input of general geometric properties of the modeled linac, profiles and depth dose curves for a specific photon nominal energy (6 MV), and the automated modeling of other beam properties. Some manual tuning of the beam model is required. To evaluate its accuracy, the confidence limit concept [J. Venselaar et al., ''Tolerances for the accuracy of photon beam dose calculations of treatment planning systems,'' Radiother. Oncol. 60, 191-201 (2001)] was used, which is a method supported by ESTRO. Measurements were conducted with a 2D diode array at the commissioned linac as amore » final check of the beam model and to evaluate whether the generated plans were deliverable and accurate. Results: The comparison and evaluation of calculated data points and measured data according to the method applied confirmed the accuracy of the beam model. The profiles had a confidence limit of 1.1% and the depth dose curves had a confidence limit of 1.7%, both of which were well below the tolerance limit of 2%. Plan specific QC measurements and evaluation verified that different plans generated in the TPS were deliverable with sufficient accuracy at the commissioned linac, as none of the 160 beams for the 20 different plans evaluated had a fraction of approved data points below 90%, the local clinical approval criterion for delivery QA measurements. Conclusions: This study is a validation of the new TPS as it verifies that the generated plans are deliverable at a commissioned linac with adequate accuracy. A thorough investigation of the treatment plan quality will require a separate study. The TPS is proving to be a useful and time-saving complement, especially for clinics having a single unit for helical delivery among its conventional linacs.« less

Authors:
; ; ;  [1]
  1. Medical Radiation Physics, Clinical Sciences, Lund University, Lund SE-221 85 (Sweden)
Publication Date:
OSTI Identifier:
22096877
Resource Type:
Journal Article
Journal Name:
Medical Physics
Additional Journal Information:
Journal Volume: 38; Journal Issue: 1; Other Information: (c) 2011 American Association of Physicists in Medicine; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0094-2405
Country of Publication:
United States
Language:
English
Subject:
62 RADIOLOGY AND NUCLEAR MEDICINE; 61 RADIATION PROTECTION AND DOSIMETRY; 43 PARTICLE ACCELERATORS; 60 APPLIED LIFE SCIENCES; ACCURACY; COMMISSIONING; COMPUTERIZED TOMOGRAPHY; CT-GUIDED RADIOTHERAPY; DELIVERY; DEPTH DOSE DISTRIBUTIONS; DOSIMETRY; LINEAR ACCELERATORS; PATIENTS; PHOTON BEAMS; PHOTONS; PLANNING; RADIATION DOSES; SIMULATION; VALIDATION; VERIFICATION

Citation Formats

Petersson, Kristoffer, Ceberg, Crister, Engstroem, Per, Knoeoes, Tommy, and Medical Radiation Physics, Clinical Sciences, Lund University, Lund. Beam commissioning and measurements validating the beam model in a new TPS that converts helical tomotherapy plans to step-and-shoot IMRT plans. United States: N. p., 2011. Web. doi:10.1118/1.3519975.
Petersson, Kristoffer, Ceberg, Crister, Engstroem, Per, Knoeoes, Tommy, & Medical Radiation Physics, Clinical Sciences, Lund University, Lund. Beam commissioning and measurements validating the beam model in a new TPS that converts helical tomotherapy plans to step-and-shoot IMRT plans. United States. https://doi.org/10.1118/1.3519975
Petersson, Kristoffer, Ceberg, Crister, Engstroem, Per, Knoeoes, Tommy, and Medical Radiation Physics, Clinical Sciences, Lund University, Lund. 2011. "Beam commissioning and measurements validating the beam model in a new TPS that converts helical tomotherapy plans to step-and-shoot IMRT plans". United States. https://doi.org/10.1118/1.3519975.
@article{osti_22096877,
title = {Beam commissioning and measurements validating the beam model in a new TPS that converts helical tomotherapy plans to step-and-shoot IMRT plans},
author = {Petersson, Kristoffer and Ceberg, Crister and Engstroem, Per and Knoeoes, Tommy and Medical Radiation Physics, Clinical Sciences, Lund University, Lund},
abstractNote = {Purpose: A new type of treatment planning system called SHAREPLAN has been studied, which enables the transfer of treatment plans generated for helical tomotherapy delivery to plans that can be delivered on C-arm linacs. The purpose is to ensure continuous patient treatment during periods of unscheduled downtime for the TomoTherapy unit, particularly in clinics without a backup unit. The purpose of this work was to verify that the plans generated in this novel planning system are deliverable and accurate. The work consists primarily of beam commissioning, verification of the beam model, and measurements verifying that generated plans are deliverable with sufficient accuracy. Methods: The beam commissioning process involves input of general geometric properties of the modeled linac, profiles and depth dose curves for a specific photon nominal energy (6 MV), and the automated modeling of other beam properties. Some manual tuning of the beam model is required. To evaluate its accuracy, the confidence limit concept [J. Venselaar et al., ''Tolerances for the accuracy of photon beam dose calculations of treatment planning systems,'' Radiother. Oncol. 60, 191-201 (2001)] was used, which is a method supported by ESTRO. Measurements were conducted with a 2D diode array at the commissioned linac as a final check of the beam model and to evaluate whether the generated plans were deliverable and accurate. Results: The comparison and evaluation of calculated data points and measured data according to the method applied confirmed the accuracy of the beam model. The profiles had a confidence limit of 1.1% and the depth dose curves had a confidence limit of 1.7%, both of which were well below the tolerance limit of 2%. Plan specific QC measurements and evaluation verified that different plans generated in the TPS were deliverable with sufficient accuracy at the commissioned linac, as none of the 160 beams for the 20 different plans evaluated had a fraction of approved data points below 90%, the local clinical approval criterion for delivery QA measurements. Conclusions: This study is a validation of the new TPS as it verifies that the generated plans are deliverable at a commissioned linac with adequate accuracy. A thorough investigation of the treatment plan quality will require a separate study. The TPS is proving to be a useful and time-saving complement, especially for clinics having a single unit for helical delivery among its conventional linacs.},
doi = {10.1118/1.3519975},
url = {https://www.osti.gov/biblio/22096877}, journal = {Medical Physics},
issn = {0094-2405},
number = 1,
volume = 38,
place = {United States},
year = {Sat Jan 15 00:00:00 EST 2011},
month = {Sat Jan 15 00:00:00 EST 2011}
}