Highlights
- •A validation phantom underwent multi-dosimeter benchmarking.
- •An ultrasound-guided radiotherapy system was verified with the validation phantom.
- •Phantom measurements were acquired with deformable 3D dosimeters.
- •An improvement in delivery accuracy with the ultrasound-guidance was quantified.
- •The phantom shows potential as a tool for quantifying the impact of image guidance.
Abstract
Objectives
The purpose of this study was to dosimetrically benchmark gel dosimetry measurements
in a dynamically deformable abdominal phantom for intrafraction image guidance through
a multi-dosimeter comparison. Once benchmarked, the study aimed to perform a proof-of-principle
study for validation measurements of an ultrasound image-guided radiotherapy delivery
system.
Methods
The phantom was dosimetrically benchmarked by delivering a liver VMAT plan and measuring
the 3D dose distribution with DEFGEL dosimeters. Measured doses were compared to the
treatment planning system and measurements acquired with radiochromic film and an
ion chamber. The ultrasound image guidance validation was performed for a hands-free
ultrasound transducer for the tracking of liver motion during treatment.
Results
Gel dosimeters were compared to the TPS and film measurements, showing good qualitative
dose distribution matches, low γ values through most of the high dose region, and
average 3%/5 mm γ-analysis pass rates of 99.2%(0.8%) and 90.1%(0.8%), respectively.
Gel dosimeter measurements matched ion chamber measurements within 3%. The image guidance
validation study showed the measurement of the treatment delivery improvements due
to the inclusion of the ultrasound image guidance system. Good qualitative matching
of dose distributions and improvements of the γ-analysis results were observed for
the ultrasound-gated dosimeter compared to the ungated dosimeter.
Conclusions
DEFGEL dosimeters in phantom showed good agreement with the planned dose and other
dosimeters for dosimetric benchmarking. Ultrasound image guidance validation measurements
showed good proof-of-principle of the utility of the phantom system as a method of
validating ultrasound-based image guidance systems and potentially other image guidance
methods.
Keywords
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References
- Proof of concept of MRI-guided tracked radiation delivery: tracking one-dimensional motion.Phys Med Biol. 2012; 57: 7863-7872
- Effects of motion on the total dose distribution.Semin Radiat Oncol. 2004; 14: 41-51
- On the dose to a moving target while employing different IMRT delivery mechanisms.Radiother Oncol. 2007; 83: 49-56
- Issues in respiratory motion compensation during external-beam radiotherapy.Int J Radiat Oncol Biol Phys. 2002; 52: 1389-1399
- Respiratory movement of the pancreas: an ultrasonic study.J Ultrasound Med. 1984; 3: 317-320
- Analysis of movement of intrathoracic neoplasms using ultrafast computerized tomography.Int J Radiat Oncol Biol Phys. 1990; 18: 671-677
- Ultrasound quantitation of respiratory organ motion in the upper abdomen.Br J Radiol. 1994; 67: 1096-1102
- Deep inspiration breath-hold technique for lung tumors: the potential value of target immobilization and reduced lung density in dose escalation.Int J Radiat Oncol Biol Phys. 1999; 45: 603-611
- Dosimetric evaluation of lung tumor immobilization using breath hold at deep inspiration.Int J Radiat Oncol Biol Phys. 2001; 50: 1091-1098
- Magnitude and influencing factors of respiration-induced liver motion during abdominal compression in patients with intrahepatic tumors.Radiat Oncol. 2017; 12: 9
- Comparison of the liver's respiratory motion in the supine and upright positions: concise communication.J Nucl Med. 1979; 20: 733-735
- Assessment of hepatic respiratory excursion.J Nucl Med. 1972; 13: 758-759
- Effects of intra-fraction motion on IMRT dose delivery: statistical analysis and simulation.Phys Med Biol. 2002; 47: 2203-2220
- An experimental investigation on intra-fractional organ motion effects in lung IMRT treatments.Phys Med Biol. 2003; 48: 1773-1784
- Magnitude, impact, and management of respiration-induced target motion in radiotherapy treatment: a comprehensive review.J Med Phys. 2017; 42: 101-115
- Dosimetric effect of respiratory motion on volumetric-modulated arc therapy-based lung SBRT treatment delivered by TrueBeam machine with flattening filter-free beam.J Appl Clin Med Phys. 2013; 14: 4370
- Irradiation synchronized with respiration gate.Int J Radiat Oncol Biol Phys. 1989; 17: 853-857
- Potential benefits of eliminating planning target volume expansions for patient breathing in the treatment of liver tumors.Int J Radiat Oncol Biol Phys. 1997; 38: 613-617
- Organ motion and its management.Int J Radiat Oncol Biol Phys. 2001; 50: 265-278
- Dose-response relationship in local radiotherapy for hepatocellular carcinoma.Int J Radiat Oncol Biol Phys. 2002; 54: 150-155
- Observation of a dose-control relationship for lung and liver tumors after stereotactic body radiation therapy.Int J Radiat Oncol Biol Phys. 2009; 73: 112-118
- Simultaneous tumour dose escalation and liver sparing in Stereotactic Body Radiation Therapy (SBRT) for liver tumours due to CTV-to-PTV margin reduction.Radiother Oncol. 2008; 87: 432-438
- Respiratory gating for liver tumors: use in dose escalation.Int J Radiat Oncol Biol Phys. 2003; 55: 659-668
- Feasibility of using ultrasound for real-time tracking during radiotherapy.Med Phys. 2005; 32: 1500-1512
- Speckle tracking in a phantom and feature-based tracking in liver in the presence of respiratory motion using 4D ultrasound.Phys Med Biol. 2010; 55: 3363
- Critical assessment of intramodality 3D ultrasound imaging for prostate IGRT compared to fiducial markers.Med Phys. 2013; 40071707
- Telerobotic system concept for real-time soft-tissue imaging during radiotherapy beam delivery.Med Phys. 2010; 37: 6357-6367
- Dosimetric consequences of misalignment and realignment in prostate 3DCRT using intramodality ultrasound image guidance.Med Phys. 2010; 37: 2787-2795
- Dosimetric evolution of the breast electron boost target using 3D ultrasound imaging.Radiother Oncol. 2010; 96: 185-191
- Force and Image Adaptive Strategies for Robotised Placement of 4D Ultrasound Probes.University of Luebeck, 2013
- Robotized 4D Ultrasound for cardiac Image- Guided Radiation Therapy.University of Luebeck. 2012;
- Ultrasound imaging in radiation therapy: from interfractional to intrafractional guidance.Cureus. 2015; 7 (e280-e)
- Intrafractional prostate motion management with the clarity autoscan system.Med Phys Int J. 2013; 1: 72-80
- Real-time Tumor Localization and Guidance for Radiotherapy Using US and MRI.University of Wisconsin Madison, National Institutes of Health2015
- Task Group 142 report: Quality assurance of medical acceleratorsa).Med Phys. 2009; 36: 4197-4212
- Quality assurance for image-guided radiation therapy utilizing CT-based technologies: a report of the AAPM TG-179.Med Phys. 2012; 39: 1946-1963
- The management of respiratory motion in radiation oncology report of AAPM Task Group 76.Med Phys. 2006; 33: 3874-3900
- Dosimetric validation of a magnetic resonance image gated radiotherapy system using a motion phantom and radiochromic film.J Appl Clin Med Phys. 2017; 18: 163-169
- ELPHA: Dynamically deformable liver phantom for real-time motion-adaptive radiotherapy treatments.Med Phys. 2019; 46: 839-850
- MRIgRT head and neck anthropomorphic QA phantom: design, development, reproducibility, and feasibility study.Med Phys. 2020; 47: 604-613
- Real-time intrafraction motion monitoring in external beam radiotherapy.Phys Med Biol. 2019; 64: 15TR01
- The clinical implementation of respiratory-gated intensity-modulated radiotherapy.Med Dosim. 2006; 31: 152-162
- Geometric and dosimetric accuracy and imaging dose of the real-time tumour tracking system of a gimbal mounted linac.Phys Med. 2015; 31: 501-509
- Deformable abdominal phantom for the validation of real-time image guidance and deformable dose accumulation.J Appl Clin Med Phys. 2019; 20: 122-133
- An improved abdominal phantom for intrafraction image guidance validation.Phys Med Biol. 2020; 65 (13nt02)
- A novel methodology for 3D deformable dosimetry.Med Phys. 2012; 39: 2203-2213
- On the need for comprehensive validation of deformable image registration, investigated with a novel 3-dimensional deformable dosimeter.Int J Rad Oncol Biol Phys. 2013; 87: 414-421
- A novel technique to enable experimental validation of deformable dose accumulation.Med Phys. 2012; 39: 765-776
Matrosic C, Holmes S, Bednarz B, Culberson W. Evaluation of a clinical dose accumulation algorithm using deformable gel dosimetry. The 10th International Conference on 3D and Advanced Dosimetry. Kunshan, China 2018.
- Study of Gafchromic® EBT film response over a large dose range.Phys Med Biol. 2010; 55: N281
- On the validity of 3D polymer gel dosimetry: I. Reproducibility study.Phys Med Biol. 2013; 58: 19
- AAPM's TG-51 protocol for clinical reference dosimetry of high-energy photon and electron beams.Med Phys. 1999; 26: 1847-1870
Venning A, Mundayadan Chandroth M, Chick B, Waller B, Morgan C. Investigation of lung-tumour peripheral doses using normoxic polymer gel & film dosimeters. 10th International Conference on 3D and Advanced Dosimetry. Kunshan, China 2018.
Rosen B. Advanced radiochromic film methodologies for quantitative dosimetry of small and nonstandard fields 2015.
- An ultrasound-based motion management system utilizing 2D/3D real-time tracking for use in radiotherapy.University of Wisconsin-Madison, 2018
- A block matching based approach with multiple simultaneous templates for the real-time 2D ultrasound tracking of liver vessels.Med Phys. 2017; 44: 5889-5900
- The influence of cooling rate on the accuracy of normoxic polymer gel dosimeters.Phys Med Biol. 2007; 52: 2719-2728
- Polymer gel dosimetry.Phys Med Biol. 2010; 55: R1-R63
- Uncertainty in 3D gel dosimetry.J Phys Conf Ser. 2015; 573012008
- An anthropomorphic abdominal phantom for deformable image registration accuracy validation in adaptive radiation therapy.Med Phys. 2017; 44: 2369-2378
- Radiochromic film dosimetry: past, present, and future.Physica Med. 2011; 27: 122-134
Article info
Publication history
Published online: April 23, 2021
Accepted:
April 6,
2021
Received in revised form:
March 1,
2021
Received:
December 18,
2020
Identification
Copyright
© 2021 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.
