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Rostami A, Khalid AS, Ghafari H, Paloor SP, Peltier BO, Hammoud R, Abdelrahman S. Assessment of four dose calculation algorithms using IAEA-TECDOC-1583 with medium dependency correction factor (K med) application. Phys Med 2024; 122:103390. [PMID: 38833878 DOI: 10.1016/j.ejmp.2024.103390] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/05/2023] [Revised: 05/02/2024] [Accepted: 05/23/2024] [Indexed: 06/06/2024] Open
Abstract
PURPOSE This study discusses the measurement of dose in clinical commissioning tests described in IAEA-TECDOC-1583. It explores the application of Monte Carlo (MC) modelled medium dependency correction factors (Kmed) for accurate dose measurement in bone and lung materials using the CIRS phantom. METHODS BEAMnrc codes simulate radiation sources and model radiation transport for 6 MV and 15 MV photon beams. CT images of the CIRS phantom are converted to an MC compatible phantom. The PTW 30013 farmer chamber measures doses within modeled CIRS phantom. Kmed are determined by averaging values from four central voxels within the sensitive volume of the farmer chamber. Kmed is calculated for Dm.m and Dw.w algorithm types in bone and lung media for both photon beams. RESULTS Average modelled correction factors for Dm.m calculations using the farmer chamber are 0.976 (±0.1 %) for 6 MV and 0.979 (±0.1 %) for 15 MV in bone media. Correspondingly, correction factors for Dw.w calculations are 0.99 (±0.3 %) and 0.992 (±0.4 %), respectively. For lung media, average correction factors for Dm.m calculations are 1.02 (±0.3 %) for 6 MV and 1.022 (±0.4 %) for 15 MV. Correspondingly, correction factors for Dw.w calculations are 1.01 (±0.3 %) and 1.012 (±0.2 %), respectively. CONCLUSIONS This study highlights the significant impact of applying Kmed on dose differences between measurement and calculation during the dose audit process.
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Affiliation(s)
- Aram Rostami
- Radiation Oncology Department, National Center for Cancer Care and Research, Doha, Qatar.
| | - Abdul Sattar Khalid
- Radiation Oncology Department, National Center for Cancer Care and Research, Doha, Qatar
| | - Hamed Ghafari
- Department of Medical Physics, School of Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Satheesh Prasad Paloor
- Radiation Oncology Department, National Center for Cancer Care and Research, Doha, Qatar
| | - Bevan Orville Peltier
- Radiation Oncology Department, National Center for Cancer Care and Research, Doha, Qatar
| | - Rabih Hammoud
- Radiation Oncology Department, National Center for Cancer Care and Research, Doha, Qatar.
| | - Shihab Abdelrahman
- Radiation Oncology Department, National Center for Cancer Care and Research, Doha, Qatar
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Henry M, Templeton A, Smith R. A low-cost phantom design for evaluating spine SABR calculations in the presence of prosthetic vertebral stabilization. Phys Eng Sci Med 2024:10.1007/s13246-024-01412-1. [PMID: 38573488 DOI: 10.1007/s13246-024-01412-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2023] [Accepted: 02/26/2024] [Indexed: 04/05/2024]
Abstract
Dose-perturbation characteristics are important to consider during the calculation of radiation therapy protocols for patients who are going to receive high doses that would reach the tolerance limits of the spinal cord [1]. Several studies have investigated dose perturbations introduced by metal implants in close proximity to spine SABR treatments [2-7]. However, there is a lack of work assessing this effect using the RayStation TPS [8]. We present an initial design for a low-cost phantom to evaluate spine stereotactic ablative radiotherapy (SABR) in the presence of prosthetic vertebral stabilization. The phantom is modular, allowing the prosthetic at the centre of the phantom to be removed by exchanging the central block. It also includes space to insert ion chamber and film. The agreement of the RayStation TPS (v8.0B) collapsed cone convolution (CCC) calculation and measurement was determined for phantom versions with and without prosthetic. There was little to no change in the agreement between the measured and calculated dose when introducing metallic hardware. This suggests that our Raystation-based SABR planning approach for patients with spinal hardware meets clinical expectations. Departments without access to anthropomorphic phantoms may find this design useful but should test their phantom design in typical clinical settings to ensure it is robust to real world situations.
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Affiliation(s)
- Michelle Henry
- Genesis Care - Fiona Stanley Hospital, Murdoch, WA, Australia.
| | | | - Ruth Smith
- Te Whatu Ora - Auckland City Hospital, Auckland, New Zealand
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Callens D, Aerts K, Berkovic P, Vandewinckele L, Lambrecht M, Crijns W. Are offline ART decisions for NSCLC impacted by the type of dose calculation algorithm? Tech Innov Patient Support Radiat Oncol 2024; 29:100236. [PMID: 38313556 PMCID: PMC10835600 DOI: 10.1016/j.tipsro.2024.100236] [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: 08/18/2023] [Revised: 01/03/2024] [Accepted: 01/09/2024] [Indexed: 02/06/2024] Open
Abstract
Introduction Decisions for plan-adaptations may be impacted by a transitioning from one dose-calculation algorithm to another. This study examines the impact on dosimetric-triggered offline adaptation in LA-NSCLC in the context of a transition from superposition/convolution dose calculation algorithm (Type-B) to linear Boltzmann equation solver dose calculation algorithms (Type-C). Materials & Methods Two dosimetric-triggered offline adaptive treatment workflows are compared in a retrospective planning study on 30 LA-NSCLC patients. One workflow uses a Type-B dose calculation algorithm and the other uses Type-C. Treatment plans were re-calculated on the anatomy of a mid-treatment synthetic-CT utilizing the same algorithm utilized for pre-treatment planning. Assessment for plan-adaptation was evaluated through a decision model based on target coverage and OAR constraint violation. The impact of algorithm during treatment planning was controlled for by recalculating the Type-B plan with Type-C. Results In the Type-B approach, 13 patients required adaptation due to OAR-constraint violations, while 15 patients required adaptation in the Type-C approach. For 8 out of 30 cases, the decision to adapt was opposite in both approaches. None of the patients in our dataset encountered CTV-target underdosage that necessitated plan-adaptation. Upon recalculating the Type-B approach with the Type-C algorithm, it was shown that 10 of the original Type-B plans revealed clinically relevant dose reductions (≥3%) on the CTV in their original plans. This re-calculation identified 21 plans in total that required ART. Discussion In our study, nearly one-third of the cases would have a different decision for plan-adaption when utilizing Type-C instead of Type-B. There was no substantial increase in the total number of plan-adaptations for LA-NSCLC. However, Type-C is more sensitive to altered anatomy during treatment compared to Type-B. Recalculating Type-B plans with the Type-C algorithm revealed an increase from 13 to 21 cases triggering ART.
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Affiliation(s)
- Dylan Callens
- Laboratory of Experimental Radiotherapy, KU Leuven, Leuven, Belgium
- Department of Radiation Oncology, UZ Leuven, Leuven, Belgium
| | - Karel Aerts
- Laboratory of Experimental Radiotherapy, KU Leuven, Leuven, Belgium
| | - Patrick Berkovic
- Laboratory of Experimental Radiotherapy, KU Leuven, Leuven, Belgium
- Department of Radiation Oncology, UZ Leuven, Leuven, Belgium
| | - Liesbeth Vandewinckele
- Laboratory of Experimental Radiotherapy, KU Leuven, Leuven, Belgium
- Department of Radiation Oncology, UZ Leuven, Leuven, Belgium
| | - Maarten Lambrecht
- Laboratory of Experimental Radiotherapy, KU Leuven, Leuven, Belgium
- Department of Radiation Oncology, UZ Leuven, Leuven, Belgium
| | - Wouter Crijns
- Laboratory of Experimental Radiotherapy, KU Leuven, Leuven, Belgium
- Department of Radiation Oncology, UZ Leuven, Leuven, Belgium
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Delbaere A, Younes T, Khamphan C, Vieillevigne L. Experimental validation of absorbed dose-to-medium calculation algorithms in heterogeneous media. Phys Med Biol 2024; 69:055006. [PMID: 38266285 DOI: 10.1088/1361-6560/ad222e] [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: 10/12/2023] [Accepted: 01/24/2024] [Indexed: 01/26/2024]
Abstract
Objective.The aim of this work was to determine heterogeneous correction factorshQclin,Qreffclin,frefdetm,wto validate absorbed dose-to-mediumDm,Qclinm,fclincalculation algorithms from detector readings. The impact of detector orientation perpendicular and parallel to the beam central axis on the correction factors was also investigated.Approach.ThehQclin,Qreffclin,frefdetm,wfactors were calculated for four types of detectors (PTW PinPoint T31016, PTW microDiamond T60019, PTW microSilicon T60023 and EBT3 film) placed in different media (cortical bone, lung, adipose tissue, Teflon and RW3) for the 6 MV energy beam with a 10 × 10 cm2field size. These corrections were then applied to the detector measurements performed at different depths in heterogeneous phantoms.Main results.ThehQclin,Qreffclin,frefdetm,wfactors mainly depended on the media and slightly on the type of detector. Considering all detectors, the largest corrections were found in high-density media with values ranging from 0.911 to 0.934 in cortical bone. For comparison, the corrections in other media were closer to unity with values from 0.966 (lung and RW3) to 0.991 (adipose tissue). Except for the PinPoint T31016, detector orientation-dependence was observed especially in high-density media. A good agreement (≤1.5%) was found betweenDm,Qclinm,fclincalculations and the detector readings corrected with thehQclin,Qreffclin,frefdetm,wfactor for all studied heterogeneous phantoms.Significance.This paper could serve as an initial guideline for medical physicists involved in the validation of the advanced type-b dose calculation algorithms reportingDm,Qclinm,fclin. To our knowledge, this is the first study to assess the impact of the orientation of different detectors in heterogeneous media. The orientation dependence of the detector response observed in water may not reflect what is observed in heterogeneous media, especially in high-density media. The knowledge of thehQclin,Qreffclin,frefdetm,wfactors becomes mandatory for accurate interpretation of detector readings and comparisons withDm,Qclinm,fclincalculations.
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Affiliation(s)
- Alexia Delbaere
- Department of Medical Physics, Oncopole Claudius Regaud - Institut Universitaire du Cancer de Toulouse, F-31059 Toulouse, France
- Centre de Recherches en Cancérologie de Toulouse, UMR1037 INSERM-Université Toulouse 3-ERL5294 CNRS, Oncopole, F-31037 Toulouse, France
| | - Tony Younes
- Department of Medical Physics, Oncopole Claudius Regaud - Institut Universitaire du Cancer de Toulouse, F-31059 Toulouse, France
- Centre de Recherches en Cancérologie de Toulouse, UMR1037 INSERM-Université Toulouse 3-ERL5294 CNRS, Oncopole, F-31037 Toulouse, France
| | - Catherine Khamphan
- Department of Medical Physics, Institut du Cancer-Avignon Provence, F-84000 Avignon, France
| | - Laure Vieillevigne
- Department of Medical Physics, Oncopole Claudius Regaud - Institut Universitaire du Cancer de Toulouse, F-31059 Toulouse, France
- Centre de Recherches en Cancérologie de Toulouse, UMR1037 INSERM-Université Toulouse 3-ERL5294 CNRS, Oncopole, F-31037 Toulouse, France
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Hirashima H, Nakamura M, Nakamura K, Matsuo Y, Mizowaki T. Dosimetric verification of four dose calculation algorithms for spine stereotactic body radiotherapy. JOURNAL OF RADIATION RESEARCH 2024; 65:109-118. [PMID: 37996097 PMCID: PMC10803157 DOI: 10.1093/jrr/rrad086] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Revised: 09/18/2023] [Accepted: 10/16/2023] [Indexed: 11/25/2023]
Abstract
The applications of Type B [anisotropic analytical algorithm (AAA) and collapsed cone (CC)] and Type C [Acuros XB (AXB) and photon Monte Carlo (PMC)] dose calculation algorithms in spine stereotactic body radiotherapy (SBRT) were evaluated. Water- and bone-equivalent phantoms were combined to evaluate the percentage depth dose and dose profile. Subsequently, 48 consecutive patients with clinical spine SBRT plans were evaluated. All treatment plans were created using AXB in Eclipse. The prescription dose was 24 Gy in two fractions at a 10 MV FFF on TrueBeam. The doses were then recalculated with AAA, CC and PMC while maintaining the AXB-calculated monitor units and beam arrangement. The dose index values obtained using the four dose calculation algorithms were then compared. The AXB and PMC dose distributions agreed with the bone-equivalent phantom measurements (within ±2.0%); the AAA and CC values were higher than those in the bone-equivalent phantom region. For the spine SBRT plans, PMC, AAA and CC were overestimated compared with AXB in terms of the near minimum and maximum doses of the target and organ at risk, respectively; the mean dose difference was within 4.2%, which is equivalent with within 1 Gy. The phantom study showed that the results from AXB and PMC agreed with the measurements within ±2.0%. However, the mean dose difference ranged from 0.5 to 1 Gy in the spine SBRT planning study when the dose calculation algorithms changed. Users should incorporate a clinical introduction that includes an awareness of these differences.
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Affiliation(s)
- Hideaki Hirashima
- Department of Radiation Oncology and Image-Applied Therapy, Graduate School of Medicine, Kyoto University, 54 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto 606-8507, Japan
| | - Mitsuhiro Nakamura
- Department of Radiation Oncology and Image-Applied Therapy, Graduate School of Medicine, Kyoto University, 54 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto 606-8507, Japan
- Department of Advanced Medical Physics, Graduate School of Medicine, Kyoto University, 53 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto 606-8507, Japan
| | - Kiyonao Nakamura
- Department of Radiation Oncology and Image-Applied Therapy, Graduate School of Medicine, Kyoto University, 54 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto 606-8507, Japan
| | - Yukinori Matsuo
- Department of Radiation Oncology and Image-Applied Therapy, Graduate School of Medicine, Kyoto University, 54 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto 606-8507, Japan
| | - Takashi Mizowaki
- Department of Radiation Oncology and Image-Applied Therapy, Graduate School of Medicine, Kyoto University, 54 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto 606-8507, Japan
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Liu C, Cho Y, Magnelli A, Angelov L, Balagamwala EH, Chao ST, Xia P. The dosimetric impact of titanium implants in spinal SBRT using four commercial treatment planning algorithms. J Appl Clin Med Phys 2023; 24:e14070. [PMID: 37540084 PMCID: PMC10562029 DOI: 10.1002/acm2.14070] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Revised: 05/03/2023] [Accepted: 05/29/2023] [Indexed: 08/05/2023] Open
Abstract
To evaluate the dosimetric impact of titanium implants in spine SBRT using four dose calculation algorithms. Twenty patients with titanium implants in the spine treated with SBRT without density override (DO) were selected. The clinical plan for each patient was created in Pinnacle and subsequently imported into Eclipse (AAA and AcurosXB) and Raystation (CC) for dose evaluation with and without DO to the titanium implant. We renormalized all plans such that 90% of the tumor volume received the prescription dose and subsequently evaluated the following dose metrics: (1) the maximum dose to 0.03 cc (Dmax), dose to 99% (D99%) and 90% (D90%) of the tumor volume; (2) Dmax and volumetric metrics of the spinal cord. For the same algorithm, plans with and without DO had similar dose distributions. Differences in Dmax, D99% and D90% of the tumor were on average <2% with slightly larger variations up to 5.58% in Dmax using AcurosXB. Dmax of the spinal cord for plans calculated with DO increased but the differences were clinically insignificant for all algorithms (mean: 0.36% ± 0.7%). Comparing to the clinical plans, the relative differences for all algorithms had an average of 1.73% (-10.36%-13.21%) for the tumor metrics and -0.93% (-9.87%-10.95%) for Dmax of the spinal cord. A few cases with small tumor and spinal cord volumes, dose differences of >10% in both D99% and Dmax of the tumor, and Dmax of the spinal cord were observed. For all algorithms, the presence of titanium implants in the spine for most patients had minimal impact on dose distributions with and without DO. For the same plan calculated with different algorithms, larger differences in volumetric metrics of >10% could be observed, impacted by dose gradient at the plan normalization volume, tumor volumes, plan complexity, and partial voxel volume interpolation.
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Affiliation(s)
- Chieh‐Wen Liu
- Department of Radiation Oncology, Taussig Cancer InstituteCleveland ClinicClevelandOhioUSA
| | - Young‐Bin Cho
- Department of Radiation Oncology, Taussig Cancer InstituteCleveland ClinicClevelandOhioUSA
| | - Anthony Magnelli
- Department of Radiation Oncology, Taussig Cancer InstituteCleveland ClinicClevelandOhioUSA
| | - Lilyana Angelov
- Department of Radiation Oncology, Taussig Cancer InstituteCleveland ClinicClevelandOhioUSA
| | - Ehsan H. Balagamwala
- Department of Radiation Oncology, Taussig Cancer InstituteCleveland ClinicClevelandOhioUSA
| | - Samuel T. Chao
- Department of Radiation Oncology, Taussig Cancer InstituteCleveland ClinicClevelandOhioUSA
| | - Ping Xia
- Department of Radiation Oncology, Taussig Cancer InstituteCleveland ClinicClevelandOhioUSA
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Yanagi Y, Kubo K, Ito T, Nakamura K, Hirata M, Doi H, Monzen H. Comparing Dose Calculation Algorithms for Heterogeneous Media: Analytical Anisotropic Algorithm Versus Acuros XB (Dm/Dw) With Continuous CT Value Variation. Cureus 2023; 15:e46805. [PMID: 37954761 PMCID: PMC10635741 DOI: 10.7759/cureus.46805] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/05/2023] [Indexed: 11/14/2023] Open
Abstract
BACKGROUND To compare the doses calculated by the analytical anisotropic algorithm (AAA) and two dose reporting modes of Acuros XB (AXB(Dm) and AXB(Dw)) with varied CT values on the Eclipse (Varian Medical Systems, Palo Alto, CA). MATERIALS AND METHODS Virtual phantoms with a central layer of heterogeneous material (thickness = 2 or 5 cm) were created with Eclipse. Using single or opposed fields, the field sizes were 5 x 5 cm2 or 10 x 10 cm2. The photon energies were 6 or 10 MV, and the source-to-target distance was 100 cm. The relative doses at the center of the heterogeneous material layer were evaluated with varied CT values, from -1000 to 3000 HU. Values were normalized with the dose at 0 HU (100%) for comparative analysis. RESULTS The results obtained from continuous data for a single field, 6 MV, 5 x 5 cm2, and the heterogeneous material 5 cm, where the differences between algorithms were most pronounced, were as follows. In the low-density region (-1000 HU and -800 HU), the dose differences for AXB with reference to AAA were, respectively, -54.5% and +4.6% (AXB(Dm)) and -47.0% and +3.5% (AXB(Dw)), and in the high-density regions (1000 HU and 3000 HU) were -5.7% and -8.8% (AXB(Dm)) and +7.4% and +3.5% (AXB(Dw)), respectively. Consequently, dose differences at arbitrary CT values could be obtained. CONCLUSION Dose differences between these algorithms were clarified for heterogeneous materials. The risk of dose reduction or escalation in clinical use was clearly visible between CT values from -1000 to 3000 HU.
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Affiliation(s)
- Yuya Yanagi
- Department of Medical Physics, Graduate School of Medical Sciences, Kindai University, Osakasayama, JPN
- Department of Radiology, Shiga University of Medical Science Hospital, Otsu, JPN
| | - Kazuki Kubo
- Department of Medical Physics, Graduate School of Medical Sciences, Kindai University, Osakasayama, JPN
| | - Takaaki Ito
- Department of Medical Physics, Graduate School of Medical Sciences, Kindai University, Osakasayama, JPN
| | - Kenji Nakamura
- Department of Medical Physics, Graduate School of Medical Sciences, Kindai University, Osakasayama, JPN
| | - Makoto Hirata
- Department of Medical Physics, Graduate School of Medical Sciences, Kindai University, Osakasayama, JPN
| | - Hiroshi Doi
- Department of Radiation Oncology, Faculty of Medicine, Kindai University, Osakasayama, JPN
| | - Hajime Monzen
- Department of Medical Physics, Graduate School of Medical Sciences, Kindai University, Osakasayama, JPN
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Shaw M, Lye J, Alves A, Lehmann J, Sanagou M, Geso M, Brown R. Measuring dose in lung identifies peripheral tumour dose inaccuracy in SBRT audit. Phys Med 2023; 112:102632. [PMID: 37406592 DOI: 10.1016/j.ejmp.2023.102632] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/25/2023] [Revised: 04/25/2023] [Accepted: 06/21/2023] [Indexed: 07/07/2023] Open
Abstract
PURPOSE Stereotactic Body Radiotherapy (SBRT) for lung tumours has become a mainstay of clinical practice worldwide. Measurements in anthropomorphic phantoms enable verification of patient dose in clinically realistic scenarios. Correction factors for reporting dose to the tissue equivalent materials in a lung phantom are presented in the context of a national dosimetry audit for SBRT. Analysis of dosimetry audit results is performed showing inaccuracies of common dose calculation algorithms in soft tissue lung target, inhale lung material and at tissue interfaces. METHODS Monte Carlo based simulation of correction factors for detectors in non-water tissue was performed for the soft tissue lung target and inhale lung materials of a modified CIRS SBRT thorax phantom. The corrections were determined for Gafchromic EBT3 Film and PTW 60019 microDiamond detectors used for measurements of 168 SBRT lung plans in an end-to-end dosimetry audit. Corrections were derived for dose to medium (Dm,m) and dose to water (Dw,w) scenarios. RESULTS Correction factors were up to -3.4% and 9.2% for in field and out of field lung respectively. Overall, application of the correction factors improved the measurement-to-plan dose discrepancy. For the soft tissue lung target, agreement between planned and measured dose was within average of 3% for both film and microDiamond measurements. CONCLUSIONS The correction factors developed for this work are provided for clinical users to apply to commissioning measurements using a commercially available thorax phantom where inhomogeneity is present. The end-to-end dosimetry audit demonstrates dose calculation algorithms can underestimate dose at lung tumour/lung tissue interfaces by an average of 2-5%.
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Affiliation(s)
- Maddison Shaw
- Australian Clinical Dosimetry Service, Australian Radiation Protection and Nuclear Safety Agency, Melbourne, Australia; School of Health and Biomedical Sciences, RMIT University, Melbourne, Australia.
| | - Jessica Lye
- Australian Clinical Dosimetry Service, Australian Radiation Protection and Nuclear Safety Agency, Melbourne, Australia; Olivia Newton John Cancer Wellness and Research Centre, Austin Health, Australia
| | - Andrew Alves
- Australian Clinical Dosimetry Service, Australian Radiation Protection and Nuclear Safety Agency, Melbourne, Australia
| | - Joerg Lehmann
- Department of Radiation Oncology, Calvary Mater Newcastle, Newcastle, Australia; School of Science, RMIT University, Melbourne, Australia; School of Mathematical and Physical Sciences, University of Newcastle, Australia; Institute of Medical Physics, University of Sydney, Australia
| | - Masoumeh Sanagou
- Australian Radiation Protection and Nuclear Safety Agency, Melbourne, Australia
| | - Moshi Geso
- School of Health and Biomedical Sciences, RMIT University, Melbourne, Australia
| | - Rhonda Brown
- Australian Clinical Dosimetry Service, Australian Radiation Protection and Nuclear Safety Agency, Melbourne, Australia
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Beaulieu L, Ballester F, Granero D, Tedgren ÅC, Haworth A, Lowenstein JR, Ma Y, Mourtada F, Papagiannis P, Rivard MJ, Siebert FA, Sloboda RS, Smith RL, Thomson RM, Verhaegen F, Fonseca G, Vijande J. AAPM WGDCAB Report 372: A joint AAPM, ESTRO, ABG, and ABS report on commissioning of model-based dose calculation algorithms in brachytherapy. Med Phys 2023; 50:e946-e960. [PMID: 37427750 DOI: 10.1002/mp.16571] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2022] [Revised: 02/16/2023] [Accepted: 04/24/2023] [Indexed: 07/11/2023] Open
Abstract
The introduction of model-based dose calculation algorithms (MBDCAs) in brachytherapy provides an opportunity for a more accurate dose calculation and opens the possibility for novel, innovative treatment modalities. The joint AAPM, ESTRO, and ABG Task Group 186 (TG-186) report provided guidance to early adopters. However, the commissioning aspect of these algorithms was described only in general terms with no quantitative goals. This report, from the Working Group on Model-Based Dose Calculation Algorithms in Brachytherapy, introduced a field-tested approach to MBDCA commissioning. It is based on a set of well-characterized test cases for which reference Monte Carlo (MC) and vendor-specific MBDCA dose distributions are available in a Digital Imaging and Communications in Medicine-Radiotherapy (DICOM-RT) format to the clinical users. The key elements of the TG-186 commissioning workflow are now described in detail, and quantitative goals are provided. This approach leverages the well-known Brachytherapy Source Registry jointly managed by the AAPM and the Imaging and Radiation Oncology Core (IROC) Houston Quality Assurance Center (with associated links at ESTRO) to provide open access to test cases as well as step-by-step user guides. While the current report is limited to the two most widely commercially available MBDCAs and only for 192 Ir-based afterloading brachytherapy at this time, this report establishes a general framework that can easily be extended to other brachytherapy MBDCAs and brachytherapy sources. The AAPM, ESTRO, ABG, and ABS recommend that clinical medical physicists implement the workflow presented in this report to validate both the basic and the advanced dose calculation features of their commercial MBDCAs. Recommendations are also given to vendors to integrate advanced analysis tools into their brachytherapy treatment planning system to facilitate extensive dose comparisons. The use of the test cases for research and educational purposes is further encouraged.
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Affiliation(s)
- Luc Beaulieu
- Service de Physique Médicale et Radioprotection et Axe Oncologie du Centre de Recherche du CHU de Québec, CHU de Québec-Université Laval, Québec, Québec, Canada
- Département de Physique, de Génie Physique et d'Optique et Centre de Recherche sur le Cancer, Université Laval, Québec, Québec, Canada
| | - Facundo Ballester
- Departamento de Física Atómica, Molecular y Nuclear, IRIMED, IIS-La Fe-Universitat de Valencia, Burjassot, Spain
| | - Domingo Granero
- Departamento de Física Atómica, Molecular y Nuclear, IRIMED, IIS-La Fe-Universitat de Valencia, Burjassot, Spain
| | - Åsa Carlsson Tedgren
- Department of Health, Medicine and Caring Sciences (HMV), Radiation Physics, Linköping University, Linköping, Sweden
- Medical Radiation Physics and Nuclear Medicine, Karolinska University Hospital, Stockholm, Sweden
- Department of Oncology Pathology, Karolinska Institute, Stockholm, Sweden
| | | | - Jessica R Lowenstein
- Department of Radiation Physics, UT MD Anderson Cancer Center, Houston, Texas, USA
| | - Yunzhi Ma
- Service de Physique Médicale et Radioprotection et Axe Oncologie du Centre de Recherche du CHU de Québec, CHU de Québec-Université Laval, Québec, Québec, Canada
- Département de Physique, de Génie Physique et d'Optique et Centre de Recherche sur le Cancer, Université Laval, Québec, Québec, Canada
| | - Firas Mourtada
- Department of Radiation Oncology, Sidney Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | - Panagiotis Papagiannis
- Medical Physics Laboratory, Medical School, National and Kapodistrian University of Athens, Athens, Greece
| | - Mark J Rivard
- Department of Radiation Oncology, Alpert Medical School of Brown University, Providence, Rhode Island, USA
| | - Frank-André Siebert
- Clinic of Radiotherapy, University Hospital of Schleswig-Holstein, Campus Kiel, Kiel, Germany
| | - Ron S Sloboda
- Department of Medical Physics, Cross Cancer Institute, Edmonton, Alberta, Canada
- Department of Oncology, University of Alberta, Edmonton, Alberta, Canada
| | - Ryan L Smith
- Alfred Health Radiation Oncology, The Alfred Hospital, Melbourne, Victoria, Australia
| | - Rowan M Thomson
- Carleton Laboratory for Radiotherapy Physics, Department of Physics, Carleton University, Ottawa, Ontario, Canada
| | - Frank Verhaegen
- Department of Radiation Oncology (MAASTRO), GROW, School for Oncology and Developmental Biology, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Gabriel Fonseca
- Department of Radiation Oncology (MAASTRO), GROW, School for Oncology and Developmental Biology, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Javier Vijande
- Departamento de Física Atómica, Molecular y Nuclear, IRIMED, IIS-La Fe-Universitat de Valencia, Burjassot, Spain
- Instituto de Física Corpuscular, IFIC (UV-CSIC), Burjassot, Spain
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10
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Jurado-Bruggeman D, Muñoz-Montplet C. Considerations for radiotherapy planning with MV photons using dose-to-medium. Phys Imaging Radiat Oncol 2023; 26:100443. [PMID: 37342209 PMCID: PMC10277912 DOI: 10.1016/j.phro.2023.100443] [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: 11/15/2022] [Revised: 04/23/2023] [Accepted: 04/25/2023] [Indexed: 06/22/2023] Open
Abstract
Background and purpose Radiotherapy planning considerations were developed for the previous calculation algorithms yielding dose to water-in-water (Dw,w). Advanced algorithms improve accuracy, but their dose values in terms of dose to medium-in-medium (Dm,m) depend on the medium considered. This work aimed to show how mimicking Dw,w planning with Dm,m can introduce new issues. Materials and methods A head and neck case involving bone and metal heterogeneities outside the CTV was considered. Two different commercial algorithms were used to obtain Dm,m and Dw,w distributions. First, a plan was optimised to irradiate the PTV uniformly and get a homogeneous Dw,w distribution. Second, another plan was optimised to achieve homogeneous Dm,m. Both plans were calculated with Dw,w and Dm,m, and the differences between their dose distributions, clinical impact, and robustness were evaluated. Results Uniform irradiation produced Dm,m cold spots in bone (-4%) and implants (-10%). Uniform Dm,m compensated them by increasing fluence but, when recalculated in Dw,w, the fluence compensations produced higher doses that affected homogeneity. Additionally, doses were 1% higher for the target, and + 4% for the mandible, thus increasing toxicity risk. Robustness was impaired when increased fluence regions and heterogeneities mismatched. Conclusion Planning with Dm,m as with Dw,w can impact clinical outcome and impair robustness. In optimisation, uniform irradiation instead of homogeneous Dm,m distributions should be pursued when media with different Dm,m responses are involved. However, this requires adapting evaluation criteria or avoiding medium effects. Regardless of the approach, there can be systematic differences in dose prescription and constraints.
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Affiliation(s)
- Diego Jurado-Bruggeman
- Medical Physics and Radiation Protection Department, Catalan Institute of Oncology Girona, Girona, Spain
| | - Carles Muñoz-Montplet
- Medical Physics and Radiation Protection Department, Catalan Institute of Oncology Girona, Girona, Spain
- Department of Medical Sciences, University of Girona, Girona, Spain
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11
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Erickson BG, Cui Y, Ackerson BG, Kelsey CR, Yin FF, Niedzwiecki D, Adamson J. Uncertainties in the dosimetric heterogeneity correction and its potential effect on local control in lung SBRT. Biomed Phys Eng Express 2023; 9. [PMID: 36827685 DOI: 10.1088/2057-1976/acbeae] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Accepted: 02/24/2023] [Indexed: 02/26/2023]
Abstract
Objective. Dose calculation in lung stereotactic body radiation therapy (SBRT) is challenging due to the low density of the lungs and small volumes. Here we assess uncertainties associated with tissue heterogeneities using different dose calculation algorithms and quantify potential associations with local failure for lung SBRT.Approach. 164 lung SBRT plans were used. The original plans were prepared using Pencil Beam Convolution (PBC, n = 8) or Anisotropic Analytical Algorithm (AAA, n = 156). Each plan was recalculated with AcurosXB (AXB) leaving all plan parameters unchanged. A subset (n = 89) was calculated with Monte Carlo to verify accuracy. Differences were calculated for the planning target volume (PTV) and internal target volume (ITV) Dmean[Gy], D99%[Gy], D95%[Gy], D1%[Gy], and V100%[%]. Dose metrics were converted to biologically effective doses (BED) usingα/β= 10Gy. Regression analysis was performed for AAA plans investigating the effects of various parameters on the extent of the dosimetric differences. Associations between the magnitude of the differences for all plans and outcome were investigated using sub-distribution hazards analysis.Main results. For AAA cases, higher energies increased the magnitude of the difference (ΔDmean of -3.6%, -5.9%, and -9.1% for 6X, 10X, and 15X, respectively), as did lung volume (ΔD99% of -1.6% per 500cc). Regarding outcome, significant hazard ratios (HR) were observed for the change in the PTV and ITV D1% BEDs upon univariate analysis (p = 0.042, 0.023, respectively). When adjusting for PTV volume and prescription, the HRs for the change in the ITV D1% BED remained significant (p = 0.039, 0.037, respectively).Significance. Large differences in dosimetric indices for lung SBRT can occur when transitioning to advanced algorithms. The majority of the differences were not associated with local failure, although differences in PTV and ITV D1% BEDs were associated upon univariate analysis. This shows uncertainty in near maximal tumor dose to potentially be predictive of treatment outcome.
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Affiliation(s)
- Brett G Erickson
- Department of Radiation Oncology, Duke University Medical Center, Durham, NC, United States of America
| | - Yunfeng Cui
- Department of Radiation Oncology, Duke University Medical Center, Durham, NC, United States of America
| | - Bradley G Ackerson
- Department of Radiation Oncology, Duke University Medical Center, Durham, NC, United States of America
| | - Christopher R Kelsey
- Department of Radiation Oncology, Duke University Medical Center, Durham, NC, United States of America
| | - Fang-Fang Yin
- Department of Radiation Oncology, Duke University Medical Center, Durham, NC, United States of America
| | - Donna Niedzwiecki
- Department of Biostatistics and Bioinformatics, Duke University Medical Center, Durham, NC, United States of America
| | - Justus Adamson
- Department of Radiation Oncology, Duke University Medical Center, Durham, NC, United States of America
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12
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Rostami A, Neto AJDC, Paloor SP, Khalid AS, Hammoud R. Comparison of four commercial dose calculation algorithms in different evaluation tests. JOURNAL OF X-RAY SCIENCE AND TECHNOLOGY 2023; 31:1013-1033. [PMID: 37393487 DOI: 10.3233/xst-230079] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/03/2023]
Abstract
BACKGROUND Accurate and fast dose calculation is crucial in modern radiation therapy. Four dose calculation algorithms (AAA, AXB, CCC, and MC) are available in Varian Eclipse and RaySearch Laboratories RayStation Treatment Planning Systems (TPSs). OBJECTIVES This study aims to evaluate and compare dosimetric accuracy of the four dose calculation algorithms applying to homogeneous and heterogeneous media, VMAT plans (based on AAPM TG-119 test cases), and the surface and buildup regions. METHODS The four algorithms are assessed in homogeneous (IAEA-TECDOCE 1540) and heterogeneous (IAEA-TECDOC 1583) media. Dosimetric evaluation accuracy for VMAT plans is then analyzed, along with the evaluation of the accuracy of algorithms applying to the surface and buildup regions. RESULTS Tests conducted in homogeneous media revealed that all algorithms exhibit dose deviations within 5% for various conditions, with pass rates exceeding 95% based on recommended tolerances. Additionally, the tests conducted in heterogeneous media demonstrate high pass rates for all algorithms, with a 100% pass rate observed for 6 MV and mostly 100% pass rate for 15 MV, except for CCC, which achieves a pass rate of 94%. The results of gamma index pass rate (GIPR) for dose calculation algorithms in IMRT fields show that GIPR (3% /3 mm) for all four algorithms in all evaluated tests based on TG119, are greater than 97%. The results of the algorithm testing for the accuracy of superficial dose reveal variations in dose differences, ranging from -11.9% to 7.03% for 15 MV and -9.5% to 3.3% for 6 MV, respectively. It is noteworthy that the AXB and MC algorithms demonstrate relatively lower discrepancies compared to the other algorithms. CONCLUSIONS This study shows that generally, two dose calculation algorithms (AXB and MC) that calculate dose in medium have better accuracy than other two dose calculation algorithms (CCC and AAA) that calculate dose to water.
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Affiliation(s)
- Aram Rostami
- Radiation Oncology Department, National Center for Cancer Care and Research, Doha, Qatar
| | | | - Satheesh Prasad Paloor
- Radiation Oncology Department, National Center for Cancer Care and Research, Doha, Qatar
| | - Abdul Sattar Khalid
- Radiation Oncology Department, National Center for Cancer Care and Research, Doha, Qatar
| | - Rabih Hammoud
- Radiation Oncology Department, National Center for Cancer Care and Research, Doha, Qatar
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13
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Kosaka T, Takatsu J, Inoue T, Hara N, Mitsuhashi T, Suzuki M, Shikama N. Effective clinical applications of Monte Carlo-based independent secondary dose verification software for helical tomotherapy. Phys Med 2022; 104:112-122. [PMID: 36395639 DOI: 10.1016/j.ejmp.2022.11.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Revised: 10/28/2022] [Accepted: 11/05/2022] [Indexed: 11/17/2022] Open
Abstract
PURPOSE To investigate the scope of the effective clinical application of Monte Carlo (MC)-based independent dose verification software for helical tomotherapy. METHODS DoseCHECK was selected as the MC-based dose calculation software. First, the dose calculation accuracy of DoseCHECK was evaluated with film and chamber measurements in a water-equivalent phantom. Second, the dose calculation accuracy was examined in several heterogeneous materials. Finally, dosimetric comparisons between DoseCHECK and the treatment planning system (TPS) were performed for clinical patient plans. Prostate IMRT, head and neck IMRT (HN), total body irradiation (TBI), and brain stereotactic radiotherapy (SRT) were evaluated. RESULT The DoseCHECK calculations agreed with the chamber and film measurements in the homogenous phantom. For heterogeneous phantom cases, the dose differences between DoseCHECK and TPS were within 3 %, except in air, in which large dose differences of 20 % were observed. In clinical patient plans, the median dose differences between the lung Dmean in TBI cases and the normal brain Dmean in brain SRT cases were significantly >3 %. For HN and brain SRT cases, the median target dose differences were >3 %. CONCLUSION Our results show that independent dose verification with the MC algorithm can detect systematic errors caused by the lack of heterogeneity correction in the TPS. In particular, MC-based independent dose verification is required for HN, TBI, and brain SRT cases in helical tomotherapy.
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Affiliation(s)
- Takahiro Kosaka
- Department of Radiation Oncology, Graduate School of Medicine, Juntendo University, 2-1-1 Hongo, Bunkyo-ku, Tokyo 113-8421, Japan; Department of Radiology, Juntendo University Urayasu Hospital, 2-1-1 Tomioka, Urayasu-shi, Chiba 279-0021, Japan.
| | - Jun Takatsu
- Department of Radiation Oncology, Faculty of Medicine, Juntendo University, 2-1-1 Hongo, Bunkyo-ku, Tokyo 113-8421, Japan.
| | - Tatsuya Inoue
- Department of Radiology, Juntendo University Urayasu Hospital, 2-1-1 Tomioka, Urayasu-shi, Chiba 279-0021, Japan; Department of Radiation Oncology, Faculty of Medicine, Juntendo University, 2-1-1 Hongo, Bunkyo-ku, Tokyo 113-8421, Japan.
| | - Naoya Hara
- Department of Radiology, Juntendo University Hospital, 3-1-3 Hongo, Bunkyo-ku, Tokyo 113-8431, Japan.
| | - Taira Mitsuhashi
- Department of Radiology, Juntendo University Urayasu Hospital, 2-1-1 Tomioka, Urayasu-shi, Chiba 279-0021, Japan.
| | - Michimasa Suzuki
- Department of Radiology, Juntendo University Urayasu Hospital, 2-1-1 Tomioka, Urayasu-shi, Chiba 279-0021, Japan.
| | - Naoto Shikama
- Department of Radiation Oncology, Graduate School of Medicine, Juntendo University, 2-1-1 Hongo, Bunkyo-ku, Tokyo 113-8421, Japan; Department of Radiation Oncology, Faculty of Medicine, Juntendo University, 2-1-1 Hongo, Bunkyo-ku, Tokyo 113-8421, Japan; Department of Radiology, Juntendo University Hospital, 3-1-3 Hongo, Bunkyo-ku, Tokyo 113-8431, Japan.
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14
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Pawałowski B, Ryczkowski A, Panek R, Sobocka-Kurdyk U, Graczyk K, Piotrowski T. Accuracy of the doses computed by the Eclipse treatment planning system near and inside metal elements. Sci Rep 2022; 12:5974. [PMID: 35396569 PMCID: PMC8993896 DOI: 10.1038/s41598-022-10072-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Accepted: 03/25/2022] [Indexed: 11/09/2022] Open
Abstract
Metal artefacts degrade clinical image quality which decreases the confidence of using computed tomography (CT) for the delineation of key structures for treatment planning and leads to dose errors in affected areas. In this work, we investigated accuracy of doses computed by the Eclipse treatment planning system near and inside metallic elements for two different computation algorithms. An impact of CT metal artefact reduction methods on the resulting calculated doses has also been assessed. A water phantom including Gafchromic film and metal inserts was irradiated (max dose 5 Gy) using a 6 MV photon beam. Three materials were tested: titanium, alloy 600, and tungsten. The phantom CT images were obtained with the pseudo-monoenergetic reconstruction (PMR) and the iterative metal artefact reduction (iMAR). Image sets were used for dose calculation using an Eclipse treatment planning station (TPS). Monte Carlo (MC) simulations were used to predict the true dose distribution in the phantom allowing for comparison with doses measured by film and calculated by TPS. Measured and simulated percentage depth doses (PDDs) were not statistically different (p > 0.618). Regional differences were observed at edges of metallic objects (max 8% difference). However, PDDs simulated with and without film were statistically different (p < 0.002). PDDs calculated by the Acuros XB algorithm based on the dose-to-medium approach best matched the MC reference regardless of the CT reconstruction methods and inserts used (p > 0.078). PDDs obtained using other algorithms significantly differ from the MC values (p < 0.011). The Acuros XB algorithm with a dose-to-medium approach provides reliable dose calculation in all metal regions when using the Varian system. The inability of the AAA algorithm to model backscatter dose significantly limits its clinical application in the presence of metal. No significant impact on the dose calculation was found for a range of metal artefact reduction strategies.
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Affiliation(s)
- Bartosz Pawałowski
- Department of Medical Physics, Greater Poland Cancer Centre, Garbary 15, 61-866, Poznan, Poland.,Department of Technical Physics, Poznan University of Technology, Poznan, Poland
| | - Adam Ryczkowski
- Department of Medical Physics, Greater Poland Cancer Centre, Garbary 15, 61-866, Poznan, Poland.,Department of Electroradiology, Poznan University of Medical Sciences, Poznan, Poland
| | - Rafał Panek
- Medical Physics and Clinical Engineering, Nottingham University Hospitals NHS Trust, Nottingham, UK.,School of Medicine, University of Nottingham, Nottingham, UK
| | - Urszula Sobocka-Kurdyk
- Department of Medical Physics, Greater Poland Cancer Centre, Garbary 15, 61-866, Poznan, Poland.,Faculty of Health Sciences, Calisia University, Kalisz, Poland
| | - Kinga Graczyk
- Department of Medical Physics, Greater Poland Cancer Centre, Garbary 15, 61-866, Poznan, Poland
| | - Tomasz Piotrowski
- Department of Medical Physics, Greater Poland Cancer Centre, Garbary 15, 61-866, Poznan, Poland. .,Department of Electroradiology, Poznan University of Medical Sciences, Poznan, Poland.
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15
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Hansen CR, Hussein M, Bernchou U, Zukauskaite R, Thwaites D. Plan quality in radiotherapy treatment planning - Review of the factors and challenges. J Med Imaging Radiat Oncol 2022; 66:267-278. [PMID: 35243775 DOI: 10.1111/1754-9485.13374] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2021] [Accepted: 12/14/2021] [Indexed: 12/25/2022]
Abstract
A high-quality treatment plan aims to best achieve the clinical prescription, balancing high target dose to maximise tumour control against sufficiently low organ-at-risk dose for acceptably low toxicity. Treatment planning (TP) includes multiple steps from simulation/imaging and segmentation to technical plan production and reporting. Consistent quality across this process requires close collaboration and communication between clinical and technical experts, to clearly understand clinical requirements and priorities and also practical uncertainties, limitations and compromises. TP quality depends on many aspects, starting from commissioning and quality management of the treatment planning system (TPS), including its measured input data and detailed understanding of TPS models and limitations. It requires rigorous quality assurance of the whole planning process and it links to plan deliverability, assessable by measurement-based verification. This review highlights some factors influencing plan quality, for consideration for optimal plan construction and hence optimal outcomes for each patient. It also indicates some challenges, sources of difference and current developments. The topics considered include: the evolution of TP techniques; dose prescription issues; tools and methods to evaluate plan quality; and some aspects of practical TP. The understanding of what constitutes a high-quality treatment plan continues to evolve with new techniques, delivery methods and related evidence-based science. This review summarises the current position, noting developments in the concept and the need for further robust tools to help achieve it.
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Affiliation(s)
- Christian Rønn Hansen
- Laboratory of Radiation Physics, Odense University Hospital, Odense, Denmark.,Department of Clinical Research, University of Southern Denmark, Odense, Denmark.,Institute of Medical Physics, School of Physics, University of Sydney, Sydney, NSW, Australia.,Danish Centre for Particle Therapy, Aarhus University Hospital, Aarhus, Denmark
| | - Mohammad Hussein
- Metrology for Medical Physics Centre, National Physical Laboratory, Teddington, UK
| | - Uffe Bernchou
- Laboratory of Radiation Physics, Odense University Hospital, Odense, Denmark.,Department of Clinical Research, University of Southern Denmark, Odense, Denmark
| | - Ruta Zukauskaite
- Department of Clinical Research, University of Southern Denmark, Odense, Denmark.,Department of Oncology, Odense University Hospital, Odense, Denmark
| | - David Thwaites
- Institute of Medical Physics, School of Physics, University of Sydney, Sydney, NSW, Australia
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16
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Erickson BG, Ackerson BG, Kelsey CR, Yin FF, Adamson J, Cui Y. The effect of various dose normalization strategies when implementing linear Boltzmann transport equation dose calculation for lung SBRT planning. Pract Radiat Oncol 2022; 12:446-456. [DOI: 10.1016/j.prro.2022.02.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Revised: 01/19/2022] [Accepted: 02/07/2022] [Indexed: 11/16/2022]
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17
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Mahuvava C, Esplen NM, Poirier Y, Kry SF, Bazalova-Carter M. Dose calculations for pre-clinical radiobiology experiments conducted with single-field cabinet irradiators. Med Phys 2022; 49:1911-1923. [PMID: 35066889 DOI: 10.1002/mp.15487] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2021] [Revised: 11/10/2021] [Accepted: 12/21/2021] [Indexed: 11/10/2022] Open
Abstract
PURPOSE To provide percentage depth-dose (PDD) data along the central axis for dosimetry calculations in small-animal radiation biology experiments performed in cabinet irradiators. The PDDs are provided as a function of source-to-surface distance (SSD), field size and animal size. METHODS The X-ray tube designs for four biological cabinet irradiators, the RS2000, RT250, MultiRad350 and XRAD320, were simulated using the BEAMnrc Monte Carlo code to generate 160, 200, 250 and 320 kVp photon beams, respectively. The 320 kVp beam was simulated with two filtrations: a soft F1 aluminium filter and a hard F2 thoraeus filter made of aluminium, tin and copper. Beams were collimated into circular fields with diameters of 0.5 - 10 cm at SSDs of 10 - 60 cm. Monte Carlo dose calculations in 1 - 5-cm diameter homogeneous (soft tissue) small-animal phantoms as well as in heterogeneous phantoms with 3-mm diameter cylindrical lung and bone inserts (rib and cortical bone) were performed using DOSXYZnrc. The calculated depth doses in three test-cases were estimated by applying SSD, field size and animal size correction factors to a reference case (40 cm SSD, 1 cm field and 5 cm animal size) and these results were compared with the specifically simulated (i.e., expected) doses to assess the accuracy of this method. Dosimetry for two test-case scenarios of 160 and 250 kVp beams (representative of end-user beam qualities) was also performed, whereby the simulated PDDs at two different depths were compared with the results based on the interpolation from reference data. RESULTS The depth doses for three test-cases calculated at 200, 320 kVp F1 and 320 kVp F2, with half value layers (HVL) ranging from ∼0.6 mm to 3.6 mm Cu, agreed well with the expected doses, yielding dose differences of 1.2, 0.1 and 1.0%, respectively. The two end-user test-cases for 160 and 250 kVp beams with respective HVLs of ∼0.8 and 1.8 mm Cu yielded dose differences of 1.4 and 3.2% between the simulated and the interpolated PDDs. The dose increase at the bone-tissue proximal interface ranged from 1.2 to 2.5 times the dose in soft tissue for rib and 1.3 to 3.7 times for cortical bone. The dose drop-off at 1-cm depth beyond the bone ranged from 1.3 - 6.0% for rib and 3.2 - 11.7% for cortical bone. No drastic dose perturbations occurred in the presence of lung, with lung-tissue interface dose of >99% of soft tissue dose and <3% dose increase at 1-cm depth beyond lung. CONCLUSIONS The developed dose estimation method can be used to translate the measured dose at a point to dose at any depth in small-animal phantoms, making it feasible for pre-clinical calculation of dose distributions in animals irradiated with cabinet-style irradiators. The dosimetric impact of bone must be accurately quantified as dramatic dose perturbations at and beyond the bone interfaces can occur due to the relative importance of the photoelectric effect at kilovoltage energies. These results will help improve dosimetric accuracy in pre-clinical experiments. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Courage Mahuvava
- Department of Physics and Astronomy, University of Victoria, Victoria, British Columbia, V8P 5C2, Canada
| | - Nolan Matthew Esplen
- Department of Physics and Astronomy, University of Victoria, Victoria, British Columbia, V8P 5C2, Canada
| | - Yannick Poirier
- Department of Medical Physics, McGill University, Montreal, Quebec, H4A 3J1, Canada
| | - Stephen F Kry
- Department of Radiation Physics, University of Texas MD Anderson, Cancer Centre, Houston, TX, 77030, USA
| | - Magdalena Bazalova-Carter
- Department of Physics and Astronomy, University of Victoria, Victoria, British Columbia, V8P 5C2, Canada
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18
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Kumar L, Bhushan M, Kishore V, Chowdhary R, Barik S, Sharma A, Gairola M. Dosimetric influence of acuros XB dose-to-medium and dose-to-water reporting modes on carcinoma cervix using intensity-modulated radiation therapy and volumetric rapidarc technique. J Med Phys 2022; 47:10-19. [PMID: 35548039 PMCID: PMC9084581 DOI: 10.4103/jmp.jmp_64_21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Revised: 11/05/2021] [Accepted: 12/08/2021] [Indexed: 11/25/2022] Open
Abstract
Aim: We aimed to evaluate the dosimetric influence of Acuros XB (AXB) dose-to-medium (Dm) and dose-to-water (Dw) reporting mode on carcinoma cervix using intensity-modulated radiation therapy (IMRT) and RapidArc (RA) technique. Materials and Methods: A cohort of thirty patients cared for carcinoma cervix was retrospectively selected for the study. Plans were computed using analytical anisotropic algorithm (AAA), AXB-Dm, and AXB-Dw algorithms for dosimetric comparison. A paired t-test and Pitman–Morgan dispersion test were executed to appraise the difference in mean values and the inter-patient variability of the differences. Results: The dose–volume parameters were higher for AXB-Dw in contrast to AAA for IMRT and RA plans, excluding D98%, minimum dose to planning target volume (PTV) and rectum mean dose (RA). There was no systematic trend observed in dose–volume parameters for PTV and organs at risk (OARs) between AXB-Dm and AXB-Dw for IMRT and RA plans. The dose–volume parameters for target were higher for AXB-Dm in comparison to AAA in IMRT and RA plans, except D98% and minimum dose to PTV. Analysis envisaged less inter-patient variability while switching from AAA to AXB-Dm in comparison to those switching from AAA to AXB-Dw. Conclusions: The present study reveals the important difference between AAA, AXB-Dm, and AXB-Dw computations for cervix carcinoma using IMRT and RA techniques. The inter-patient variability and systematic difference in dose–volume parameters computed using AAA, AXB-Dm, and AXB-Dw algorithms present the possible impact on the dose prescription to PTV and their relative constraints to OARs for IMRT and RA techniques. This may help in the decision-making in clinic while switching from AAA to AXB (Dm or Dw) algorithm for cervix carcinoma using IMRT and RA techniques.
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19
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Jurado-Bruggeman D, Muñoz-Montplet C, Hernandez V, Saez J, Fuentes-Raspall R. Impact of the dose quantity used in MV photon optimization on dose distribution, robustness, and complexity. Med Phys 2021; 49:648-665. [PMID: 34855988 DOI: 10.1002/mp.15389] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Revised: 10/09/2021] [Accepted: 11/18/2021] [Indexed: 11/09/2022] Open
Abstract
PURPOSE Convolution/superposition algorithms used in megavoltage (MV) photon radiotherapy model radiation transport in water, yielding dose to water-in-water (Dw,w ). Advanced algorithms constitute a step forward, but their dose distributions in terms of dose to medium-in-medium (Dm,m ) or dose to water-in-medium (Dw,m ) can be problematic when used in plan optimization due to their different dose responses to some atomic composition heterogeneities. Failure to take this into account can lead to undesired overcorrections and thus to unnoticed suboptimal and unrobust plans. Dose to reference-like medium (Dref,m* ) was recently introduced to overcome these limitations while ensuring accurate transport. This work evaluates and compares the performance of these four dose quantities in planning target volume (PTV)-based optimization. METHODS We considered three cases with heterogeneities inside the PTV: virtual phantom with water surrounded by bone; head and neck; and lung. These cases were planned with volumetric modulated arc therapy (VMAT) technique, optimizing with the same setup and objectives for each dose quantity. We used different algorithms of the Varian Eclipse treatment planning system (TPS): Acuros XB (AXB) for Dm,m and Dw,m , and Analytical Anisotropic Algorithm (AAA) for Dw,w . Dref,m* was obtained from Dm,m distributions using an in-house software considering water as the reference medium (Dw,m* ). The optimization process consisted of: (1) common first optimization, (2) dose distribution computed for each quantity, (3) re-optimization, and (4) final calculation for each dose quantity. The dose distribution, robustness to patient setup errors, and complexity of the plans were analyzed and compared. RESULTS The quantities showed similar dose distributions after the optimization but differed in terms of plan robustness. The cases with soft tissue and high-density heterogeneities followed the same pattern. For AXB Dm,m , cold regions appeared in the heterogeneities after the first optimization. They were compensated in the second optimization through local fluence increases, but any positional mismatch impacted robustness, with clinical target volume (CTV) variations from the nominal scenario around +3% for bone and up to +7% for metal. For AXB Dw,m the pattern was inverse (hot regions compensated by fluence decreases) and more pronounced, with CTV dose variations around -7% for bone and up to -17% for metal. Neither AXB Dw,m* nor AAA Dw,w presented these dose inhomogeneities, which resulted in more robust plans. However, Dw,w differed markedly from the other quantities in the lung case because of its lower radiation transport accuracy. AXB Dm,m was the most complex of the four dose quantities and AXB Dw,m* the least complex, though we observed no major differences in this regard. CONCLUSIONS The dose quantity used in MV photon optimization can affect plan robustness. Dw,w distributions from convolution/superposition algorithms are robust but may not provide sufficient radiation transport accuracy in some cases. Dm,m and Dw,m from advanced algorithms can compromise robustness because their different responses to some composition heterogeneities introduce additional fluence compensations. Dref,m* offers advantages in plan optimization and evaluation, producing accurate and robust plans without increasing complexity. Dref,m* can be easily implemented as a built-in feature of the TPS and can facilitate and simplify the treatment planning process when using advanced algorithms. Final reporting can be kept in Dm,m or Dw,m for clinical correlations.
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Affiliation(s)
- Diego Jurado-Bruggeman
- Medical Physics and Radiation Protection Department, Institut Català d'Oncologia, Girona, Spain
| | - Carles Muñoz-Montplet
- Medical Physics and Radiation Protection Department, Institut Català d'Oncologia, Girona, Spain.,Department of Medical Sciences, University of Girona, Girona, Spain
| | - Victor Hernandez
- Department of Medical Physics, Hospital Universitari Sant Joan de Reus, IISPV, Tarragona, Spain.,Universitat Rovira i Virgili, Tarragona, Spain
| | - Jordi Saez
- Department of Radiation Oncology, Hospital Clínic de Barcelona, Barcelona, Spain
| | - Rafael Fuentes-Raspall
- Department of Medical Sciences, University of Girona, Girona, Spain.,Radiation Oncology Department, Institut Català d'Oncologia, Girona, Spain
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Hardcastle N, Hughes J, Siva S, Kron T. Dose calculation and reporting with a linear Boltzman transport equation solver in vertebral SABR. Phys Eng Sci Med 2021; 45:43-48. [PMID: 34813052 DOI: 10.1007/s13246-021-01076-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2021] [Accepted: 11/05/2021] [Indexed: 11/29/2022]
Abstract
Vertebral Stereotactic ablative body radiotherapy (SABR) involves substantial tumour density heterogeneities. We evaluated the impact of a linear Boltzmann transport equation (LBTE) solver dose calculation on vertebral SABR dose distributions. A sequential cohort of 20 patients with vertebral metastases treated with SABR were selected. Treatment plans were initially planned with a convolution style dose calculation algorithm. The plan was copied and recalculated with a LBTE algorithm reporting both dose to water (Dw) or dose to medium (Dm). Target dose as a function of CT number, and spinal cord dose was compared between algorithms. Compared with a convolution algorithm, there was minimal change in PTV D90% with LBTE. LBTE reporting Dm resulted in reduced GTV D50% by (mean, 95% CI) 2.2% (1.9-2.6%) and reduced Spinal Cord PRV near-maximum dose by 3.0% (2.0-4.1%). LBTE reporting Dw resulted in increased GTV D50% by 2.4% (1.8-3.0%). GTV D50% decreased or increased with increasing CT number with Dm or Dw respectively. LBTE, reporting either Dm or Dw resulted in decreased central spinal cord dose by 8.7% (7.1-10.2%) and 7.2% (5.7-8.8%) respectively. Reported vertebral SABR tumour dose when calculating with an LBTE algorithm depends on tumour density. Spinal cord near-maximum dose was lower when using LBTE algorithm reporting Dm, which may result in higher spinal cord doses being delivered than with a convolution style algorithm. Spinal cord central dose was significantly lower with LBTE, potentially reflecting LBTE transport approximations.
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Affiliation(s)
- Nicholas Hardcastle
- Physical Sciences, Peter MacCallum Cancer Centre, 305 Grattan St, Melbourne, VIC, 3012, Australia. .,Sir Peter MacCallum Department of Oncology, University of Melbourne, Melbourne, Australia. .,Centre for Medical Radiation Physics, University of Wollongong, Wollongong, Australia.
| | - Jeremy Hughes
- Physical Sciences, Peter MacCallum Cancer Centre, 305 Grattan St, Melbourne, VIC, 3012, Australia
| | - Shankar Siva
- Physical Sciences, Peter MacCallum Cancer Centre, 305 Grattan St, Melbourne, VIC, 3012, Australia.,Sir Peter MacCallum Department of Oncology, University of Melbourne, Melbourne, Australia
| | - Tomas Kron
- Physical Sciences, Peter MacCallum Cancer Centre, 305 Grattan St, Melbourne, VIC, 3012, Australia.,Sir Peter MacCallum Department of Oncology, University of Melbourne, Melbourne, Australia.,Centre for Medical Radiation Physics, University of Wollongong, Wollongong, Australia
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