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Elcadi ZA, El Moussaoui M, Aouadi S, Sukumaran R, Hammoud R, Al-Hammadi N, Toufique Y, Bouhali O. GATE Monte Carlo approach to heterogeneity dose distribution in small fields used in radiation therapy. Biomed Phys Eng Express 2024; 10:035021. [PMID: 38518360 DOI: 10.1088/2057-1976/ad36cd] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2023] [Accepted: 03/22/2024] [Indexed: 03/24/2024]
Abstract
The Accurate dosage prediction in Radiation Therapy is challenging, prompting a need for precision beyond conventional clinical Treatment Planning Systems (TPS). Monte Carlo-based methods are sought for their superior accuracy. The aim of this study is to compare dose distributions between the ACUROS algorithm and the GATE platform in various tissue densities and field sizes, focusing on smaller fields. This study was initiated with a homogeneous validation of the TrueBeam STX system, using measurements obtained from the Centre Hospitalier Interregional Edith Cavell (CHIREC) in Brussels. The validation compared dosimetric functions (Percentage Depth Dose (PDD), Dose profile (DP) and Collimator scatter fraction (CSF)) employing the GAMMA index with a 2% / 2 mm criterion tolerance. Following this, heterogeneous studies examined dose distributions between the ACUROS algorithm and the GATE platform in various tissue densities and field sizes, with a specific focus on smaller fields. Simulations were conducted using both platforms on chest phantoms with heterogeneous slabs representing bone, lung, and heart, each housing a central tumor. The impact of electronic equilibrium on tumors for different small field sizes was evaluated. Results showed a remarkable 99% agreement between measurements and GATE calculations in the homogeneous validation of the TrueBeam STX system. However, in heterogeneous studies, ACUROS consistently overestimated lung doses by up to 8% compared to GATE simulation, especially evident with a flattening filter and smaller beam sizes at density interfaces. This highlights significant dose estimation discrepancies between ACUROS and GATE, emphasizing the need for precise calculations. The findings support exploring Monte Carlo-based methods for enhanced accuracy in Radiation Therapy treatment planning.
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Affiliation(s)
- Z A Elcadi
- Electrical and Computer Engeneering, Texas A&M University at Qatar, PO Box 23874, Doha, Qatar
| | - M El Moussaoui
- CHIREC Hospital Group, Department of Medical Physics, Brussels, Belgium
| | - S Aouadi
- National Center for Cancer Care and Research, NCCCR Hamad Medical Corporation, Doha, Qatar
| | - R Sukumaran
- National Center for Cancer Care and Research, NCCCR Hamad Medical Corporation, Doha, Qatar
| | - R Hammoud
- National Center for Cancer Care and Research, NCCCR Hamad Medical Corporation, Doha, Qatar
| | - N Al-Hammadi
- National Center for Cancer Care and Research, NCCCR Hamad Medical Corporation, Doha, Qatar
| | - Y Toufique
- Energy, Materials, Numerical Physics, Ecole Normale Supérieure (ENS), Abdelmalek Essaadi University, Tetouan, Morocco
| | - O Bouhali
- Electrical and Computer Engeneering, Texas A&M University at Qatar, PO Box 23874, Doha, Qatar
- Qatar Center of Quantum Computing, College of Science and Engineering, Hamad Bin Khalifa University, Qatar
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Zuber SH, Hadi MFRA, Samson DO, Jayamani J, Rabaiee NA, Aziz MZA, Hashikin NAA, Ying CK, Yusof MFM, Hashim R. Dosimetric Analysis of Rhizophora-based Phantom Material in Radiation Therapy Applications Using Monte Carlo GATE Simulation. J Med Phys 2023; 48:358-364. [PMID: 38223797 PMCID: PMC10783191 DOI: 10.4103/jmp.jmp_75_23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Revised: 09/05/2023] [Accepted: 09/23/2023] [Indexed: 01/16/2024] Open
Abstract
Purpose This study aims to determine the percentage depth dose (PDD) of a phantom material made from soy-lignin bonded Rhizophora spp. particleboard coated with a gloss finish by using Monte Carlo Geant4 Application for Tomographic Emission (GATE) simulation. Materials and Methods The particleboard was fabricated using a hot pressing technique at target density of 1.0 g·cm-3 and the elemental fraction was recorded for the simulation. The PDD was simulated in the GATE simulation using the linear accelerator Elekta Synergy model for the water phantom and Rhizophora phantom, and the results were compared with the experimental PDD performed by several studies. Beam flatness and beam symmetry were also measured in this study. Results The simulated PDD for Rhizophora and water was in agreement with the experimental PDD of water with overall discrepancies of 0% to 8.7% at depth ranging from 1.0 to 15.0 cm. In the GATE simulation, all the points passed the clinical 3%/3 mm criterion in comparison with water, with the final percentage of 2.34% for Rhizophora phantom and 2.49% for the water phantom simulated in GATE. Both the symmetries are all within the range of an acceptable value of 2.0% according to the recommendation, with the beam symmetry of the water phantom and Rhizophora phantom at 0.58% and 0.28%, respectively. Conclusions The findings of this study provide the necessary foundation to confidently use the phantom for radiotherapy purposes, especially in treatment planning.
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Affiliation(s)
- Siti Hajar Zuber
- Diagnostic Imaging and Radiotherapy, Faculty of Health Sciences, Universiti Kebangsaan Malaysia, 50300, Kuala Lumpur, Malaysia
| | | | | | | | - Nor Ain Rabaiee
- Department of Radiology, Kulliyyah of Medicine, International Islamic University Malaysia, 25200, Malaysia
| | - Mohd Zahri Abdul Aziz
- Oncology and Radiotherapy Unit, Advanced Medical and Dental Institute, Universiti Sains Malaysia, 13200, Malaysia
| | | | - Chee Keat Ying
- Oncology and Radiotherapy Unit, Advanced Medical and Dental Institute, Universiti Sains Malaysia, 13200, Malaysia
| | | | - Rokiah Hashim
- School of Industrial Technology, Universiti Sains Malaysia, 11800, Penang, Malaysia
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Parwaie W, Geraily G, Shirazi A, Yarahmadi M, Shakeri A, Ardekani MA. Evaluation of lung heterogeneity effects on dosimetric parameters in small photon fields using MAGIC polymer gel, Gafchromic film, and Monte Carlo simulation. Appl Radiat Isot 2020; 166:109233. [PMID: 32836165 DOI: 10.1016/j.apradiso.2020.109233] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Revised: 04/20/2020] [Accepted: 05/17/2020] [Indexed: 10/23/2022]
Abstract
In this work, the performance of MAGIC polymer gel in measuring dosimetric parameters beyond lung heterogeneity in small fields was investigated. All data were obtained using MAGIC, EBT2, and MC in four small field sizes. The maximum local differences between MAGIC and MC were less than 5.1, 3.9, 3.1, and 2.6% for PDD values behind lung heterogeneity at 5, 10, 20, and 30 mm field sizes, respectively. The findings showed that MAGIC is a suitable tool for dosimetry behind low-density heterogeneity.
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Affiliation(s)
- Wrya Parwaie
- Department of Medical Physics and Biomedical Engineering, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Ghazale Geraily
- Department of Medical Physics and Biomedical Engineering, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran.
| | - Alireza Shirazi
- Department of Medical Physics and Biomedical Engineering, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Mehran Yarahmadi
- Department of Medical Physics, Faculty of Medicine, Kurdistan University of Medical Sciences, Sanandaj, Iran
| | - Ahmad Shakeri
- Valiasr Radiotherapy Oncology Center, Valiasr Hospital, Qom, Iran
| | - Mahdieh Afkhami Ardekani
- Department of Radiology, Faculty of Para-Medicine, Hormozgan University of Medical Sciences, Bandar Abbas, Iran.
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Sarigul N, Surucu M, Reft C, Malin M, Yegingil Z, Aydogan B. A practical method for quantifying dose in bone and lung using TLDs when using 6 and 15 MV photon beams. Phys Med Biol 2020; 65:05NT01. [PMID: 32028274 DOI: 10.1088/1361-6560/ab735d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
This paper presents a practical method for converting dose measured with thermoluminescent dosimeters (TLD) to dose in lung and bone for 6 MV and 15 MV photon beams. Monte Carlo (MC) simulations and Burlin cavity theory calculations were performed to calculate [Formula: see text], the dose-to-TLD to dose-to-medium conversion factor. A practical method was proposed for converting TLD-measured-dose to dose-in-medium using the TLD dose calibration in water and [Formula: see text] dose-to-medium to dose-to-water conversion factor. Theoretical calculations for [Formula: see text] were performed using photon spectrum weighted parameters and were compared with MC simulations. Verification of the proposed method was done using phantoms having either bone or lung equivalent slabs stacked in between solid water slabs. Percent depth dose (PDD) curves were measured using 0.089 cm thick LiF:Mg,Ti (TLD-100) dosemeters placed at various depths within these phantoms. They were then corrected with [Formula: see text] factors using the proposed dose conversion method, and were compared with the MC simulations. For 6 MV beam, the MC calculated [Formula: see text] factors were 0.942 and 1.002 for bone and lung, and for 15 MV it was 0.927 and 1.005 for bone and lung, respectively. The difference between the MC simulated and spectrum weighted theoretical [Formula: see text] factors were within 3% for both lung and bone. The PDD curves measured with TLD-100 chips that were corrected using the proposed method agreed well within 1.5% of the MC simulated PDD curves for both the water/lung/water and water/bone/water (WBW) phantoms. The dose-to-medium correction using MC simulated [Formula: see text] is convenient, easy, and accurate. Therefore, it can be used instead of Burlin cavity theory, especially in media with high atomic numbers such as bone for accurate dose quantification.
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Affiliation(s)
- Neslihan Sarigul
- Institute of Nuclear Science, Hacettepe University, 06532 Ankara, Turkey. Both authors contributed equally to this manuscript
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Schreuder AN, Bridges DS, Rigsby L, Blakey M, Janson M, Hedrick SG, Wilkinson JB. Validation of the RayStation Monte Carlo dose calculation algorithm using a realistic lung phantom. J Appl Clin Med Phys 2019; 20:127-137. [PMID: 31763759 PMCID: PMC6909115 DOI: 10.1002/acm2.12777] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Revised: 10/10/2019] [Accepted: 10/17/2019] [Indexed: 12/25/2022] Open
Abstract
PURPOSE Our purposes are to compare the accuracy of RaySearch's analytical pencil beam (APB) and Monte Carlo (MC) algorithms for clinical proton therapy and to present clinical validation data using a novel animal tissue lung phantom. METHODS We constructed a realistic lung phantom composed of a rack of lamb resting on a stack of rectangular natural cork slabs simulating lung tissue. The tumor was simulated using 70% lean ground lamb meat inserted in a spherical hole with diameter 40 ± 5 mm carved into the cork slabs. A single-field plan using an anterior beam and a two-field plan using two anterior-oblique beams were delivered to the phantom. Ion chamber array measurements were taken medial and distal to the tumor. Measured doses were compared with calculated RayStation APB and MC calculated doses. RESULTS Our lung phantom enabled measurements with the MatriXX PT at multiple depths in the phantom. Using the MC calculations, the 3%/3 mm gamma index pass rates, comparing measured with calculated doses, for the distal planes were 74.5% and 85.3% for the APB and 99.1% and 92% for the MC algorithms. The measured data revealed up to 46% and 30% underdosing within the distal regions of the target volume for the single and the two field plans when APB calculations are used. These discrepancies reduced to less than 18% and 7% respectively using the MC calculations. CONCLUSIONS RaySearch Laboratories' Monte Carlo dose calculation algorithm is superior to the pencil-beam algorithm for lung targets. Clinicians relying on the analytical pencil-beam algorithm should be aware of its pitfalls for this site and verify dose prior to delivery. We conclude that the RayStation MC algorithm is reliable and more accurate than the APB algorithm for lung targets and therefore should be used to plan proton therapy for patients with lung cancer.
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Affiliation(s)
- Andries N. Schreuder
- Provision Center for Proton Therapy – Knoxville6450 Provision Cares WayKnoxvilleTN37909USA
| | - Daniel S. Bridges
- Provision Center for Proton Therapy – Knoxville6450 Provision Cares WayKnoxvilleTN37909USA
| | - Lauren Rigsby
- Provision Center for Proton Therapy – Knoxville6450 Provision Cares WayKnoxvilleTN37909USA
| | - Marc Blakey
- Provision Center for Proton Therapy – Knoxville6450 Provision Cares WayKnoxvilleTN37909USA
| | - Martin Janson
- RaySearch LaboratoriesSveavägen 44SE‐103 65StockholmSweden
| | - Samantha G. Hedrick
- Provision Center for Proton Therapy – Knoxville6450 Provision Cares WayKnoxvilleTN37909USA
| | - John B. Wilkinson
- Provision Center for Proton Therapy – Knoxville6450 Provision Cares WayKnoxvilleTN37909USA
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Rahimi SA, Hashemi B, Mahdavi SR. Estimation of Dosimetric Parameters based on K NR and K NCSF Correction Factors for Small Field Radiation Therapy at 6 and 18 MV Linac Energies using Monte Carlo Simulation Methods. J Biomed Phys Eng 2019; 9:37-50. [PMID: 30881933 PMCID: PMC6409371] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2015] [Accepted: 12/24/2016] [Indexed: 06/09/2023]
Abstract
BACKGROUND Estimating dosimetric parameters for small fields under non-reference conditions leads to significant errors if done based on conventional protocols used for large fields in reference conditions. Hence, further correction factors have been introduced to take into account the influence of spectral quality changes when various detectors are used in non-reference conditions at different depths and field sizes. OBJECTIVE Determining correction factors (KNR and KNCSF) recommended recently for small field dosimetry formalism by American Association of Physicists in Medicine (AAPM) for different detectors at 6 and 18 MV photon beams. METHODS EGSnrc Monte Carlo code was used to calculate the doses measured with different detectors located in a slab phantom and the recommended KNR and KNCSF correction factors for various circular small field sizes ranging from 5-30 mm diameters. KNR and KNCSF correction factors were determined for different active detectors (a pinpoint chamber, EDP-20 and EDP-10 diodes) in a homogeneous phantom irradiated to 6 and 18 MV photon beams of a Varian linac (2100C/D). RESULTS KNR correction factor estimated for the highest small circular field size of 30 mm diameter for the pinpoint chamber, EDP-20 and EDP-10 diodes were 0.993, 1.020 and 1.054; and 0.992, 1.054 and 1.005 for the 6 and 18 MV beams, respectively. The KNCSF correction factor estimated for the lowest circular field size of 5 mm for the pinpoint chamber, EDP-20 and EDP-10 diodes were 0.994, 1.023, and 1.040; and 1.000, 1.014, and 1.022 for the 6 and 18 MV photon beams, respectively. CONCLUSION Comparing the results obtained for the detectors used in this study reveals that the unshielded diodes (EDP-20 and EDP-10) can confidently be recommended for small field dosimetry as their correction factors (KNR and KNCSF) was close to 1.0 for all small field sizes investigated and are mainly independent from the electron beam spot size.
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Affiliation(s)
- S A Rahimi
- PhD Candidate, Department of Medical Physics, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
- Assistant Professor, Department of Basic Sciences, Faculty of Health Sciences, Mazandaran University of Medical Sciences, Sari, Iran
| | - B Hashemi
- Associate Professor, Department of Medical Physics, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - S R Mahdavi
- Associate Professor, Department of Medical Physics, Faculty of Medicine, Iran University of Medical Sciences, Tehran, Iran
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Choi HJ, Park H, Shin WG, Kim JI, Min CH. Development of a Geant4-based independent patient dose validation system with an elaborate multileaf collimator simulation model. J Appl Clin Med Phys 2019; 20:94-106. [PMID: 30672648 PMCID: PMC6370989 DOI: 10.1002/acm2.12530] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2018] [Revised: 12/13/2018] [Accepted: 12/18/2018] [Indexed: 11/11/2022] Open
Abstract
Despite the improvements in the dose calculation models of the commercial treatment planning systems (TPS), their ability to accurately predict patient dose is still limited. One of the limitations is caused by the simplified model of the multileaf collimator (MLC). The aim of this study was to develop a Monte Carlo (MC) method‐based independent patient dose validation system with an elaborate MLC model for more accurate dose evaluation. Varian Clinac 2300 IX was simulated using Geant4 toolkits, after which MC commissioning with measurements was performed to validate the simulation model. A DICOM‐RT interface was developed to obtain the beam delivery conditions including the hundreds of MLC motions. Finally, the TPS dose distributions were compared with the MC dose distributions for water phantom cases and a patient case. Our results show that the TPS overestimated the absolute abutting leakage dose in the closed MLC field, with about 20% more of the maximum dose than that of the MC calculation. For water phantom cases, the dose distributions inside the target region were almost identical with the dose difference of less than 2%, while the dose near the edge of the target shows difference about 10% between Geant4 and TPS due to geometrical differences in MLC model. For the patient analysis, the Geant4 and TPS doses of all organs were matched well within 1.4% of the prescribed dose. However, for organs located in areas with high ratio of leaf pairs with distances less than 10 mm leaf pair (LP(<10mm)), the maximum dose of TPS was overestimated by about 3% of the prescribed dose. These dose comparison results demonstrate that our system for calculating the patient dose is quite accurate. Furthermore, if the MLC sequences in treatment plan have a large ratio of LP(short), more than 3% dose difference in normal tissue could be seen.
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Affiliation(s)
- Hyun Joon Choi
- Department of Radiation Convergence Engineering, Yonsei University, Wonju, Republic of Korea
| | - Hyojun Park
- Department of Radiation Convergence Engineering, Yonsei University, Wonju, Republic of Korea
| | - Wook-Geun Shin
- Department of Radiation Convergence Engineering, Yonsei University, Wonju, Republic of Korea
| | - Jung-In Kim
- Department of Radiation Oncology, Seoul National University Hospital, Seoul, Republic of Korea.,Institute of Radiation Medicine, Seoul National University Medical Research Center, Seoul, Republic of Korea.,Biomedical Research Institute, Seoul National University Hospital, Seoul, Republic of Korea
| | - Chul Hee Min
- Department of Radiation Convergence Engineering, Yonsei University, Wonju, Republic of Korea
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Phantom Verification of AAA and Acuros Dose Calculations for Lung Cancer: Do Tumor Size and Regression Matter? Pract Radiat Oncol 2019; 9:29-37. [DOI: 10.1016/j.prro.2018.06.008] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2018] [Revised: 05/22/2018] [Accepted: 06/10/2018] [Indexed: 12/14/2022]
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Soh RCX, Tay GH, Lew WS, Lee JCL. A depth dose study between AAA and AXB algorithm against Monte Carlo simulation using AIP CT of a 4D dataset from a moving phantom. Rep Pract Oncol Radiother 2018; 23:413-424. [PMID: 30197577 DOI: 10.1016/j.rpor.2018.08.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2017] [Revised: 05/15/2018] [Accepted: 08/09/2018] [Indexed: 10/28/2022] Open
Abstract
Aim To identifying depth dose differences between the two versions of the algorithms using AIP CT of a 4D dataset. Background Motion due to respiration may challenge dose prediction of dose calculation algorithms during treatment planning. Materials and methods The two versions of depth dose calculation algorithms, namely, Anisotropic Analytical Algorithm (AAA) version 10.0 (AAAv10.0), AAA version 13.6 (AAAv13.6) and Acuros XB dose calculation (AXB) algorithm version 10.0 (AXBv10.0), AXB version 13.6 (AXBv13.6), were compared against a full MC simulated 6X photon beam using QUASAR respiratory motion phantom with a moving chest wall. To simulate the moving chest wall, a 4 cm thick wax mould was attached to the lung insert of the phantom. Depth doses along the central axis were compared in the anterior and lateral beam direction for field sizes 2 × 2 cm2, 4 × 4 cm2 and 10 × 10 cm2. Results For the lateral beam direction, the moving chest wall highlighted differences of up to 105% for AAAv10.0 and 40% for AXBv10.0 from MC calculations in the surface and buildup doses. AAAv13.6 and AXBv13.6 agrees with MC predictions to within 10% at similar depth. For anterior beam doses, dose differences predicted for both versions of AAA and AXB algorithm were within 7% and results were consistent with static heterogeneous studies. Conclusions The presence of the moving chest wall was capable of identifying depth dose differences between the two versions of the algorithms. These differences could not be identified in the static chest wall as shown in the anterior beam depth dose calculations.
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Affiliation(s)
- Roger Cai Xiang Soh
- Department of Radiation Oncology, National University Cancer Institute, Singapore.,Division of Physics and Applied Physics, Nanyang Technological University, Singapore
| | - Guan Heng Tay
- Division of Radiation Oncology, National Cancer Centre, Singapore
| | - Wen Siang Lew
- Division of Physics and Applied Physics, Nanyang Technological University, Singapore
| | - James Cheow Lei Lee
- Division of Physics and Applied Physics, Nanyang Technological University, Singapore.,Division of Radiation Oncology, National Cancer Centre, Singapore
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Singh N, Painuly NK, Chaudhari LN, Chairmadurai A, Verma T, Shrotiya D, Bhatt CP. Evaluation of AAA and XVMC Algorithms for Dose Calculation in Lung Equivalent Heterogeneity in Photon Fields: A Comparison of Calculated Results with Measurements. J Biomed Phys Eng 2018; 8:223-230. [PMID: 30320026 PMCID: PMC6169117] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2015] [Accepted: 12/08/2015] [Indexed: 06/08/2023]
Abstract
AIMS The aims of the present work are (1) to evaluate dose calculation accuracy of two commonly used algorithms for 15 MV small photon fields in a medium encompassing heterogeneity and (2) to compare them with measured results obtained from gafchromic film EBT2. MATERIALS AND METHODS Authors employed kailwood (Pinus Wallichiana) to mimic lung. Briefly, seven Kailwood plates, each measuring 25x25 cm2 of varying thicknesses totaling 13 cm equivalent to the mean thickness of an adult human lung, were sandwiched between 5 cm tissue equivalent material from top and 10 cm below. Physical measurements were performed using Radiochromic film EBT2. The field sizes of 1x1, 2x2, 5x5 and 10x10 cm2 were selected at 100 cm SSD. Simulations were performed using EGSnrc/DOSRZnrc Monte Carlo code. The dose variation inside the inhomogeneity and near the interface was calculated using AAA & XVMC algorithm. RESULTS Preliminary results show that there is large variation of dose inside inhomogeneity. The maximum variation of dose inside the inhomogeneity for 1x1 cm2 was found 40% by AAA and 4.5% by XVMC compared to measured/simulated results. For the field size of 2x2 cm2, these figures were 27% by AAA & 3.5% by XVMC. For 5x5 cm2 field size, the variation is small which becomes insignificant for larger fields. CONCLUSION The results presented in this work indicate that for smaller fields, XVMC algorithm gives more realistic prediction, while there is the need for caution on using AAA algorithm for dose calculations involving small area irradiation encompassing heterogeneities and low-density media.
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Affiliation(s)
- N Singh
- Department of Radiotherapy, King George Medical University, Lucknow, India
| | - N K Painuly
- Department of Radiotherapy, King George Medical University, Lucknow, India
| | - L N Chaudhari
- M.S. Patel Cancer Center, Shree Krishna Hospital and Research Centre, Karamsad, Gujarat, India
| | - A Chairmadurai
- Department of Radiotherapy, Jaypee Hospital, Noida, Uttar Pradesh, India
| | - T Verma
- Department of Radiotherapy, King George Medical University, Lucknow, India
| | - D Shrotiya
- Department of Radiotherapy, J.K.Cancer Hospital, Kanpur, Uttar Pradesh, India
| | - C P Bhatt
- Department of Radiation Oncology, Batra Hospital, New Delhi, India
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Independent dose validation system for Gamma Knife radiosurgery, using a DICOM-RT interface and Geant4. Phys Med 2018; 51:117-124. [PMID: 29914795 DOI: 10.1016/j.ejmp.2018.06.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/04/2018] [Revised: 06/08/2018] [Accepted: 06/09/2018] [Indexed: 11/21/2022] Open
Abstract
Leksell GammaPlan was specifically designed for Gamma Knife (GK) radiosurgery planning, but it has limited accuracy for estimating the dose distribution in inhomogeneous areas, such as the embolization of arteriovenous malformations. We aimed to develop an independent patient dose validation system based on a patient-specific model, constructed using a DICOM-RT interface and the Geant4 toolkit. Leksell Gamma Knife Perfexion was designed in Geant4.10.00 and includes a DICOM-RT interface. Output factors for each collimator in a sector and dose distributions in a spherical water phantom calculated using a Monte Carlo (MC) algorithm were compared with the output factors calculated by the tissue maximum ratio (TMR) 10 algorithm and dose distributions measured using film, respectively. Studies using two types of water phantom and two patient simulation cases were evaluated by comparing the dose distributions calculated by the MC, the TMR and the convolution algorithms. The water phantom studies showed that if the beam size is small and the target is located in heterogeneous media, the dose difference could be up to 11%. In the two patient simulations, the TMR algorithm overestimated the dose by about 4% of the maximum dose if a complex and large bony structure was located on the beam path, whereas the convolution algorithm showed similar results to those of the MC algorithm. This study demonstrated that the in-house system could accurately verify the patient dose based on full MC simulation and so would be useful for patient cases where the dose differences are suspected.
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Dosimetric evaluation near lung and soft tissue interface region during respiratory-gated and non-gated radiotherapy: A moving phantom study. Phys Med 2017; 42:39-46. [DOI: 10.1016/j.ejmp.2017.08.011] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/28/2017] [Revised: 07/27/2017] [Accepted: 08/23/2017] [Indexed: 12/25/2022] Open
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Moura ES, Micka JA, Hammer CG, Culberson WS, DeWerd LA, Rostelato MECM, Zeituni CA. Development of a phantom to validate high-dose-rate brachytherapy treatment planning systems with heterogeneous algorithms. Med Phys 2015; 42:1566-74. [DOI: 10.1118/1.4914390] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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14
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Comparison of CCC and ETAR dose calculation algorithms in pituitary adenoma radiation treatment planning; Monte Carlo evaluation. JOURNAL OF RADIOTHERAPY IN PRACTICE 2014. [DOI: 10.1017/s1460396914000211] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
AbstractAimsTo verify the accuracy of two common absorbed dose calculation algorithms in comparison to Monte Carlo (MC) simulation for the planning of the pituitary adenoma radiation treatment.Materials and methodsAfter validation of Linac's head modelling by MC in water phantom, it was verified in Rando phantom as a heterogeneous medium for pituitary gland irradiation. Then, equivalent tissue-air ratio (ETAR) and collapsed cone convolution (CCC) algorithms were compared for a conventional three small non-coplanar field technique. This technique uses 30 degree physical wedge and 18 MV photon beams.ResultsDose distribution findings showed significant difference between ETAR and CCC of delivered dose in pituitary irradiation. The differences between MC and dose calculation algorithms were 6.40 ± 3.44% for CCC and 10.36 ± 4.37% for ETAR. None of the algorithms could predict actual dose in air cavity areas in comparison to the MC method.ConclusionsDifference between calculation and true dose value affects radiation treatment outcome and normal tissue complication probability. It is of prime concern to select appropriate treatment planning system according to our clinical situation. It is further emphasised that MC can be the method of choice for clinical dose calculation algorithms verification.
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Ong CL, Cuijpers JP, Senan S, Slotman BJ, Verbakel WFAR. Impact of the calculation resolution of AAA for small fields and RapidArc treatment plans. Med Phys 2011; 38:4471-9. [PMID: 21928616 DOI: 10.1118/1.3605468] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
PURPOSE To investigate the impact of the calculation resolution of the anisotropic analytical algorithms (AAA) for a variety of small fields in homogeneous and heterogeneous media and for RapidArc plans. METHODS Dose distributions calculated using AAA version 8.6.15 (AAA8) and 10.0.25 (AAA10) were compared to measurements performed with GafChromic EBT film, using phantoms made of polystyrene or a combination of polystyrene and cork. The accuracy of the algorithms calculated using grid resolutions of 2.5 and 1.0 mm was investigated for different field sizes, and for a limited selection of RapidArc plans (head and neck, small meningioma, and lung). Additional plans were optimized to create excessive multileaf collimator modulation and measured on a homogenous phantom. Gamma evaluation criterion of 3% dose difference and 2- or 1-mm distance to agreement (DTA) were applied to evaluate the accuracy of the algorithms. RESULTS For fields < or = 3 x 3 cm2, both versions of AAA predicted lower peak doses and broader penumbra widths than the measurements. However, AAA10 and a finer calculation grid improved the agreement. For RapidArc plans with many small multileaf collimator (MLC) segments and relatively high number of monitor units (MU), AAA8 failed to identify small dose peaks within the target. Both versions performed better in polystyrene than in cork. In homogeneous cork layers, AAA8 underestimated the average target dose for a clinical lung plan. This was improved with AAA10 calculated using a 1 mm grid. CONCLUSIONS AAA10 improves the accuracy of dose calculations, and calculation grid of 1.0 mm is superior to using 2.5 mm, although calculation times increased by factor of 5. A suitable upper MU constraint should be assigned during optimization to avoid plans with high modulation. For plans with a relative high number of monitor units, calculations using 1 mm grid resolution are recommended. For planning target volume (PTV) which contains relatively large area of low density tissue, users should be aware of possible dose underestimation in the low density region and recalculation with AAA10 grid 1.0 mm is recommended.
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Affiliation(s)
- Chin Loon Ong
- Department of Radiation Oncology, Vu University Medical Center, 1081HV Amsterdam, The Netherlands
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Kumar A, Sharma SD, Arya AK, Gupta S, Shrotriya D. Effect of low-density heterogeneities in telecobalt therapy and validation of dose calculation algorithm of a treatment planning system. J Med Phys 2011; 36:198-204. [PMID: 22228928 PMCID: PMC3249730 DOI: 10.4103/0971-6203.89967] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2011] [Revised: 08/22/2011] [Accepted: 09/09/2011] [Indexed: 11/25/2022] Open
Abstract
Telecobalt machines are still prominently used for the treatment of a variety of cancer cases in developing countries. The human body is a heterogeneous composition of variety of tissues and cavities which vary widely in their physical and radiological properties. The presence of heterogeneities in the path of telecobalt beam presents an altered dose distribution in the region of clinical interests. A computerized treatment planning system (TPS) is generally used for calculating the dose distribution in the patient. Experimental measurements were carried out in a telecobalt beam with the objectives to study the effects of low-density heterogeneities and to verify the ability of the ASHA radiotherapy TPS in predicting the altered dose distribution along the central axis and off-axis of the beam. Locally available kailwood was tested for its lung equivalence and measurements were carried out in a polymethyl methacrylate phantom by introducing lung equivalent and air gap heterogeneities. A comparison of experimentally measured and TPS calculated dose values indicates that the TPS overestimates the dose by 11.6% in lung equivalent (kailwood) heterogeneity along the central axis. Similarly, it was found that the TPS overestimates the dose by 3.9% and 5.9%, respectively, with air heterogeneity of 1.0 and 2.0 cm. While testing the adequacy of TPS in off-axis region, it was found that the TPS calculation does not indicate the widening of the beam profile in the low-density heterogeneity region. This study suggests that the effective path length based algorithm of the ASHA radiotherapy TPS is unable to achieve the recommended 3% accuracy of clinical dose calculation in heterogeneous media.
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Affiliation(s)
- Anuj Kumar
- Department of Radiotherapy, S. N. Medical College, Agra, India
| | - Sunil Dutt Sharma
- Radiological Physics and Advisory Division, Bhabha Atomic Research Centre, Anushaktinagar, Mumbai, India
| | - A. K. Arya
- Department of Radiotherapy, S. N. Medical College, Agra, India
| | - Surabhi Gupta
- Department of Radiotherapy, S. N. Medical College, Agra, India
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Fogliata A, Nicolini G, Clivio A, Vanetti E, Cozzi L. Dosimetric evaluation of Acuros XB Advanced Dose Calculation algorithm in heterogeneous media. Radiat Oncol 2011; 6:82. [PMID: 21771317 PMCID: PMC3168411 DOI: 10.1186/1748-717x-6-82] [Citation(s) in RCA: 137] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2011] [Accepted: 07/19/2011] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND A study was realised to evaluate and determine relative figures of merit of a new algorithm for photon dose calculation when applied to inhomogeneous media. METHODS The new Acuros XB algorithm implemented in the Varian Eclipse treatment planning system was compared against a Monte Carlo method (VMC++), and the Analytical Anisotropic Algorithm (AAA). The study was carried out in virtual phantoms characterized by simple geometrical structures. An insert of different material and density was included in a phantom built of skeletal-muscle and HU = 0 (setting "A"): Normal Lung (lung, 0.198 g/cm3); Light Lung (lung, 0.035 g/cm3); Bone (bone, 1.798 g/cm3); another phantom (setting "B") was built of adipose material and including thin layers of bone (1.85 g/cm3), adipose (0.92 g/cm3), cartilage (1.4745 g/cm3), air (0.0012 g/cm3). Investigations were performed for 6 and 15 MV photon beams, and for a large (13 × 13 cm2) and a small (2.8 × 13 cm2) field. RESULTS Results are provided in terms of depth dose curves, transverse profiles and Gamma analysis (3 mm/3% and 2 mm/2% distance to agreement/dose difference criteria) in planes parallel to the beam central axis; Monte Carlo simulations were assumed as reference. Acuros XB gave an average gamma agreement, with a 3 mm/3% criteria, of 100%, 86% and 100% for Normal Lung, Light Lung and Bone settings, respectively, and dose to medium calculations. The same figures were 86%, 11% and 100% for AAA, where only dose rescaled to water calculations are possible. CONCLUSIONS In conclusion, Acuros XB algorithm provides a valid and accurate alternative to Monte Carlo calculations for heterogeneity management.
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Affiliation(s)
- Antonella Fogliata
- Medical Physics Unit, Oncology Institute of Southern Switzerland, Bellinzona, Switzerland.
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Huang TC, Liang JA, Dilling T, Wu TH, Zhang G. Four-dimensional dosimetry validation and study in lung radiotherapy using deformable image registration and Monte Carlo techniques. Radiat Oncol 2010; 5:45. [PMID: 20509955 PMCID: PMC2890615 DOI: 10.1186/1748-717x-5-45] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2010] [Accepted: 05/29/2010] [Indexed: 11/15/2022] Open
Abstract
Thoracic cancer treatment presents dosimetric difficulties due to respiratory motion and lung inhomogeneity. Monte Carlo and deformable image registration techniques have been proposed to be used in four-dimensional (4D) dose calculations to overcome the difficulties. This study validates the 4D Monte Carlo dosimetry with measurement, compares 4D dosimetry of different tumor sizes and tumor motion ranges, and demonstrates differences of dose-volume histograms (DVH) with the number of respiratory phases that are included in 4D dosimetry. BEAMnrc was used in dose calculations while an optical flow algorithm was used in deformable image registration and dose mapping. Calculated and measured doses of a moving phantom agreed within 3% at the center of the moving gross tumor volumes (GTV). 4D CT image sets of lung cancer cases were used in the analysis of 4D dosimetry. For a small tumor (12.5 cm3) with motion range of 1.5 cm, reduced tumor volume coverage was observed in the 4D dose with a beam margin of 1 cm. For large tumors and tumors with small motion range (around 1 cm), the 4D dosimetry did not differ appreciably from the static plans. The dose-volume histogram (DVH) analysis shows that the inclusion of only extreme respiratory phases in 4D dosimetry is a reasonable approximation of all-phase inclusion for lung cancer cases similar to the ones studied, which reduces the calculation in 4D dosimetry.
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Affiliation(s)
- Tzung-Chi Huang
- Department of Biomedical Imaging and Radiological Sciences, National Yang Ming University, Taiwan
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