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Zhou C, Bennion N, Ma R, Liang X, Wang S, Zvolanek K, Hyun M, Li X, Zhou S, Zhen W, Lin C, Wahl A, Zheng D. A comprehensive dosimetric study on switching from a Type-B to a Type-C dose algorithm for modern lung SBRT. Radiat Oncol 2017; 12:80. [PMID: 28476138 PMCID: PMC5420128 DOI: 10.1186/s13014-017-0816-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2017] [Accepted: 05/01/2017] [Indexed: 12/26/2022] Open
Abstract
BACKGROUND Type-C dose algorithms provide more accurate dosimetry for lung SBRT treatment planning. However, because current dosimetric protocols were developed based on conventional algorithms, its applicability for the new generation algorithms needs to be determined. Previous studies on this issue used small sample sizes and reached discordant conclusions. Our study assessed dose calculation of a Type-C algorithm with current dosimetric protocols in a large patient cohort, in order to demonstrate the dosimetric impacts and necessary treatment planning steps of switching from a Type-B to a Type-C dose algorithm for lung SBRT planning. METHODS Fifty-two lung SBRT patients were included, each planned using coplanar VMAT arcs, normalized to D95% = prescription dose using a Type-B algorithm. These were compared against three Type-C plans: re-calculated plans (identical plan parameters), re-normalized plans (D95% = prescription dose), and re-optimized plans. Dosimetric endpoints were extracted and compared among the four plans, including RTOG dosimetric criteria: (R100%, R50%, D2cm, V105%, and lung V20), PTV Dmin, Dmax, Dmean, V% and D90%, PTV coverage (V100%), homogeneity index (HI), and Paddick conformity index (PCI). RESULTS Re-calculated Type-C plans resulted in decreased PTV Dmin with a mean difference of 5.2% and increased Dmax with a mean difference of 3.1%, similar or improved RTOG dose compliance, but compromised PTV coverage (mean D95% and V100% reduction of 2.5 and 8.1%, respectively). Seven plans had >5% D95% reduction (maximum reduction = 16.7%), and 18 plans had >5% V100% reduction (maximum reduction = 60.0%). Re-normalized Type-C plans restored target coverage, but yielded degraded plan conformity (average PCI reduction 4.0%), and RTOG dosimetric criteria deviation worsened in 11 plans, in R50%, D2cm, and R100%. Except for one case, re-optimized Type-C plans restored RTOG compliance achieved by the original Type-B plans, resulting in similar dosimetric values but slightly higher target dose heterogeneity (mean HI increase = 13.2%). CONCLUSIONS Type-B SBRT lung plans considerably overestimate target coverage for some patients, necessitating Type-C re-normalization or re-optimization. Current RTOG dosimetric criteria appear to remain appropriate.
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Affiliation(s)
- Christina Zhou
- School of Biological Sciences, University of Chicago, Chicago, IL USA
| | - Nathan Bennion
- Department of Radiation Oncology, University of Nebraska Medical Center, 42nd and Emile St, Omaha, NE 68198 USA
| | - Rongtao Ma
- Department of Radiation Oncology, University of Nebraska Medical Center, 42nd and Emile St, Omaha, NE 68198 USA
| | - Xiaoying Liang
- University of Florida Health Proton Therapy Institute, Jacksonville, FL USA
| | - Shuo Wang
- Department of Radiation Oncology, University of Nebraska Medical Center, 42nd and Emile St, Omaha, NE 68198 USA
| | - Kristina Zvolanek
- Department of Biological Systems Engineering, University of Nebraska Lincoln, Lincoln, NE USA
| | - Megan Hyun
- Department of Radiation Oncology, University of Nebraska Medical Center, 42nd and Emile St, Omaha, NE 68198 USA
| | - Xiaobo Li
- Department of Radiation Oncology, University of Nebraska Medical Center, 42nd and Emile St, Omaha, NE 68198 USA
- Department of Radiation Oncology, Fujian Medical University Union Hospital, Fuzhou, Fujian China
| | - Sumin Zhou
- Department of Radiation Oncology, University of Nebraska Medical Center, 42nd and Emile St, Omaha, NE 68198 USA
| | - Weining Zhen
- Department of Radiation Oncology, University of Nebraska Medical Center, 42nd and Emile St, Omaha, NE 68198 USA
| | - Chi Lin
- Department of Radiation Oncology, University of Nebraska Medical Center, 42nd and Emile St, Omaha, NE 68198 USA
| | - Andrew Wahl
- Department of Radiation Oncology, University of Nebraska Medical Center, 42nd and Emile St, Omaha, NE 68198 USA
| | - Dandan Zheng
- Department of Radiation Oncology, University of Nebraska Medical Center, 42nd and Emile St, Omaha, NE 68198 USA
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Zvolanek K, Ma R, Zhou C, Liang X, Wang S, Verma V, Zhu X, Zhang Q, Driewer J, Lin C, Zhen W, Wahl A, Zhou SM, Zheng D. Still equivalent for dose calculation in the Monte Carlo era? A comparison of free breathing and average intensity projection CT datasets for lung SBRT using three generations of dose calculation algorithms. Med Phys 2017; 44:1939-1947. [DOI: 10.1002/mp.12193] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2016] [Revised: 02/20/2017] [Accepted: 02/27/2017] [Indexed: 01/26/2023] Open
Affiliation(s)
- Kristina Zvolanek
- Department of Biological Systems Engineering; University of Nebraska-Lincoln; Lincoln NE 68588 USA
| | - Rongtao Ma
- Department of Radiation Oncology; University of Nebraska Medical Center; Omaha NE 68198 USA
| | - Christina Zhou
- School of Biological Sciences; University of Chicago; Chicago IL 60637 USA
| | - Xiaoying Liang
- University of Florida Health Proton Therapy Institute; Jacksonville FL 32206 USA
| | - Shuo Wang
- Department of Radiation Oncology; University of Nebraska Medical Center; Omaha NE 68198 USA
| | - Vivek Verma
- Department of Radiation Oncology; University of Nebraska Medical Center; Omaha NE 68198 USA
| | - Xiaofeng Zhu
- Department of Radiation Oncology; Georgetown University Hospital; Washington DC 20007 USA
| | - Qinghui Zhang
- Department of Radiation Medicine; Northwell Health; New York NY 10040 USA
| | - Joseph Driewer
- Department of Radiation Oncology; Nebraska Methodist Hospital; Omaha NE 68114 USA
| | - Chi Lin
- Department of Radiation Oncology; University of Nebraska Medical Center; Omaha NE 68198 USA
| | - Weining Zhen
- Department of Radiation Oncology; University of Nebraska Medical Center; Omaha NE 68198 USA
| | - Andrew Wahl
- Department of Radiation Oncology; University of Nebraska Medical Center; Omaha NE 68198 USA
| | - Su-Min Zhou
- Department of Radiation Oncology; University of Nebraska Medical Center; Omaha NE 68198 USA
| | - Dandan Zheng
- Department of Radiation Oncology; University of Nebraska Medical Center; Omaha NE 68198 USA
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Verma T, Painuly N, Mishra S, Shajahan M, Singh N, Bhatt M, Jamal N, Pant M. Performance Evaluation of Algorithms in Lung IMRT: A comparison of Monte Carlo, Pencil Beam, Superposition, Fast Superposition and Convolution Algorithms. J Biomed Phys Eng 2016; 6:127-138. [PMID: 27853720 PMCID: PMC5106545] [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: 05/19/2015] [Accepted: 08/22/2015] [Indexed: 11/17/2022]
Abstract
BACKGROUND Inclusion of inhomogeneity corrections in intensity modulated small fields always makes conformal irradiation of lung tumor very complicated in accurate dose delivery. OBJECTIVE In the present study, the performance of five algorithms via Monte Carlo, Pencil Beam, Convolution, Fast Superposition and Superposition were evaluated in lung cancer Intensity Modulated Radiotherapy planning. MATERIALS AND METHODS Treatment plans for ten lung cancer patients previously planned on Monte Carlo algorithm were re-planned using same treatment planning indices (gantry angel, rank, power etc.) in other four algorithms. RESULTS The values of radiotherapy planning parameters such as Mean dose, volume of 95% isodose line, Conformity Index, Homogeneity Index for target, Maximum dose, Mean dose; %Volume receiving 20Gy or more by contralateral lung; % volume receiving 30 Gy or more; % volume receiving 25 Gy or more, Mean dose received by heart; %volume receiving 35Gy or more; %volume receiving 50Gy or more, Mean dose to Easophagous; % Volume receiving 45Gy or more, Maximum dose received by Spinal cord and Total monitor unit, Volume of 50 % isodose lines were recorded for all ten patients. Performance of different algorithms was also evaluated statistically. CONCLUSION MC and PB algorithms found better as for tumor coverage, dose distribution homogeneity in Planning Target Volume and minimal dose to organ at risks are concerned. Superposition algorithms found to be better than convolution and fast superposition. In the case of tumors located centrally, it is recommended to use Monte Carlo algorithms for the optimal use of radiotherapy.
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Affiliation(s)
- T. Verma
- King George Medical University, UP, Lucknow, India
| | - N.K. Painuly
- King George Medical University, UP, Lucknow, India
| | - S.P. Mishra
- Dr.Ram Manohar Lohia Institute of Medical Sciences, Lucknow, India
| | - M. Shajahan
- Dr.Ram Manohar Lohia Institute of Medical Sciences, Lucknow, India
| | - N. Singh
- King George Medical University, UP, Lucknow, India
| | - M.L.B. Bhatt
- Dr.Ram Manohar Lohia Institute of Medical Sciences, Lucknow, India
| | - N. Jamal
- King George Medical University, UP, Lucknow, India
| | - M.C. Pant
- King George Medical University, UP, Lucknow, India
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Zheng D, Zhu X, Zhang Q, Liang X, Zhen W, Lin C, Verma V, Wang S, Wahl A, Lei Y, Zhou S, Zhang C. Target dose conversion modeling from pencil beam (PB) to Monte Carlo (MC) for lung SBRT. Radiat Oncol 2016; 11:83. [PMID: 27316922 PMCID: PMC4912806 DOI: 10.1186/s13014-016-0661-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2016] [Accepted: 06/15/2016] [Indexed: 12/26/2022] Open
Abstract
BACKGROUND A challenge preventing routine clinical implementation of Monte Carlo (MC)-based lung SBRT is the difficulty of reinterpreting historical outcome data calculated with inaccurate dose algorithms, because the target dose was found to decrease to varying degrees when recalculated with MC. The large variability was previously found to be affected by factors such as tumour size, location, and lung density, usually through sub-group comparisons. We hereby conducted a pilot study to systematically and quantitatively analyze these patient factors and explore accurate target dose conversion models, so that large-scale historical outcome data can be correlated with more accurate MC dose without recalculation. METHODS Twenty-one patients that underwent SBRT for early-stage lung cancer were replanned with 6MV 360° dynamic conformal arcs using pencil-beam (PB) and recalculated with MC. The percent D95 difference (PB-MC) was calculated for the PTV and GTV. Using single linear regression, this difference was correlated with the following quantitative patient indices: maximum tumour diameter (MaxD); PTV and GTV volumes; minimum distance from tumour to soft tissue (dmin); and mean density and standard deviation of the PTV, GTV, PTV margin, lung, and 2 mm, 15 mm, 50 mm shells outside the PTV. Multiple linear regression and artificial neural network (ANN) were employed to model multiple factors and improve dose conversion accuracy. RESULTS Single linear regression with PTV D95 deficiency identified the strongest correlation on mean-density (location) indices, weaker on lung density, and the weakest on size indices, with the following R(2) values in decreasing orders: shell2mm (0.71), PTV (0.68), PTV margin (0.65), shell15mm (0.62), shell50mm (0.49), lung (0.40), dmin (0.22), GTV (0.19), MaxD (0.17), PTV volume (0.15), and GTV volume (0.08). A multiple linear regression model yielded the significance factor of 3.0E-7 using two independent features: mean density of shell2mm (P = 1.6E-7) and PTV volume (P = 0.006). A 4-feature ANN model slightly improved the modeling accuracy. CONCLUSION Quantifiable density features were proposed, replacing simple central/peripheral location designation, which showed strong correlations with PB-to-MC target dose conversion magnitude, followed by lung density and target size. Density in the immediate outer and inner areas of the PTV showed the strongest correlations. A multiple linear regression model with one such feature and PTV volume established a high significance factor, improving dose conversion accuracy.
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Affiliation(s)
- Dandan Zheng
- />Department of Radiation Oncology, University of Nebraska Medical Center, Omaha, NE USA
| | - Xiaofeng Zhu
- />Department of Radiation Oncology, University of Nebraska Medical Center, Omaha, NE USA
| | - Qinghui Zhang
- />Department of Radiation Medicine, Northwell Health, New York, NY USA
| | - Xiaoying Liang
- />University of Florida Health Proton Therapy Institute, Jacksonville, FL USA
| | - Weining Zhen
- />Department of Radiation Oncology, University of Nebraska Medical Center, Omaha, NE USA
| | - Chi Lin
- />Department of Radiation Oncology, University of Nebraska Medical Center, Omaha, NE USA
| | - Vivek Verma
- />Department of Radiation Oncology, University of Nebraska Medical Center, Omaha, NE USA
| | - Shuo Wang
- />Department of Radiation Oncology, University of Nebraska Medical Center, Omaha, NE USA
| | - Andrew Wahl
- />Department of Radiation Oncology, University of Nebraska Medical Center, Omaha, NE USA
| | - Yu Lei
- />Department of Radiation Oncology, University of Nebraska Medical Center, Omaha, NE USA
| | - Sumin Zhou
- />Department of Radiation Oncology, University of Nebraska Medical Center, Omaha, NE USA
| | - Chi Zhang
- />School of Biological Sciences, University of Nebraska Lincoln, 1901 Vine Street, Lincoln, NE 68588-0660 USA
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Stereotactic body radiotherapy for small lung tumors in the University of Tokyo Hospital. BIOMED RESEARCH INTERNATIONAL 2014; 2014:136513. [PMID: 25110653 PMCID: PMC4109604 DOI: 10.1155/2014/136513] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/31/2014] [Revised: 06/03/2014] [Accepted: 06/18/2014] [Indexed: 01/08/2023]
Abstract
Our work on stereotactic body radiation therapy (SBRT) for primary and metastatic lung tumors will be described. The eligibility criteria for SBRT, our previous SBRT method, the definition of target volume, heterogeneity correction, the position adjustment using four-dimensional cone-beam computed tomography (4D CBCT) immediately before SBRT, volumetric modulated arc therapy (VMAT) method for SBRT, verifying of tumor position within internal target volume (ITV) using in-treatment 4D-CBCT during VMAT-SBRT, shortening of treatment time using flattening-filter-free (FFF) techniques, delivery of 4D dose calculation for lung-VMAT patients using in-treatment CBCT and LINAC log data with agility multileaf collimator, and SBRT method for centrally located lung tumors in our institution will be shown. In our institution, these efforts have been made with the goal of raising the local control rate and decreasing adverse effects after SBRT.
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Chaikh A, Giraud JY, Balosso J. A method to quantify and assess the dosimetric and clinical impact resulting from the heterogeneity correction in radiotherapy for lung cancer. INTERNATIONAL JOURNAL OF CANCER THERAPY AND ONCOLOGY 2014. [DOI: 10.14319/ijcto.0201.10] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
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Ma C, Cao J, Yin Y, Zhu J. Radiotherapy dose calculation on KV cone-beam CT image for lung tumor using the CIRS calibration. Thorac Cancer 2014; 5:68-73. [PMID: 26766975 DOI: 10.1111/1759-7714.12055] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2013] [Accepted: 05/02/2013] [Indexed: 10/26/2022] Open
Abstract
On-board kilovoltage (KV) cone-beam computed tomography (CBCT) images are used predominantly for the setup of patients' positioning. The image data can also potentially be used for dose calculation with the precise calibration of Hounsfield units (HU) to electron density (HU-density). CBCT calibration was analyzed in this study. A clinical treatment planning system was employed for CT and KV CBCT image to dose calculations and subsequent comparisons. Two HU-density tables were generated using the Computerized Imaging Reference Systems (CIRS) phantom. The results showed that a maximum ∼4% dose discrepancy was observed for inserts. The single field isodose curves were very close. The lung clinical patient study indicated that the volume of lung tumor that achieved the prescribed dose in CBCT was lower than in the CT plan. Our study showed that the dosimetric accuracy of CBCT-based dose calculation for lung tumor is acceptable only for the purpose of dosimetric checks with calibration applied. KV CBCT images cannot replace traditional CT images for dose calculation accuracy.
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Affiliation(s)
- Changsheng Ma
- Department of Radiation Oncology, Shandong Tumor Hospital Jinan, China
| | - Jianping Cao
- Department of Radiation Medicine and Protection, Medical College of Soochow University Suzhou, China
| | - Yong Yin
- Department of Radiation Oncology, Shandong Tumor Hospital Jinan, China
| | - Jian Zhu
- Department of Radiation Oncology, Shandong Tumor Hospital Jinan, China
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Takahashi W, Yamashita H, Saotome N, Iwai Y, Sakumi A, Haga A, Nakagawa K. Evaluation of heterogeneity dose distributions for Stereotactic Radiotherapy (SRT): comparison of commercially available Monte Carlo dose calculation with other algorithms. Radiat Oncol 2012; 7:20. [PMID: 22315950 PMCID: PMC3305645 DOI: 10.1186/1748-717x-7-20] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2011] [Accepted: 02/09/2012] [Indexed: 12/02/2022] Open
Abstract
Background The purpose of this study was to compare dose distributions from three different algorithms with the x-ray Voxel Monte Carlo (XVMC) calculations, in actual computed tomography (CT) scans for use in stereotactic radiotherapy (SRT) of small lung cancers. Methods Slow CT scan of 20 patients was performed and the internal target volume (ITV) was delineated on Pinnacle3. All plans were first calculated with a scatter homogeneous mode (SHM) which is compatible with Clarkson algorithm using Pinnacle3 treatment planning system (TPS). The planned dose was 48 Gy in 4 fractions. In a second step, the CT images, structures and beam data were exported to other treatment planning systems (TPSs). Collapsed cone convolution (CCC) from Pinnacle3, superposition (SP) from XiO, and XVMC from Monaco were used for recalculating. The dose distributions and the Dose Volume Histograms (DVHs) were compared with each other. Results The phantom test revealed that all algorithms could reproduce the measured data within 1% except for the SHM with inhomogeneous phantom. For the patient study, the SHM greatly overestimated the isocenter (IC) doses and the minimal dose received by 95% of the PTV (PTV95) compared to XVMC. The differences in mean doses were 2.96 Gy (6.17%) for IC and 5.02 Gy (11.18%) for PTV95. The DVH's and dose distributions with CCC and SP were in agreement with those obtained by XVMC. The average differences in IC doses between CCC and XVMC, and SP and XVMC were -1.14% (p = 0.17), and -2.67% (p = 0.0036), respectively. Conclusions Our work clearly confirms that the actual practice of relying solely on a Clarkson algorithm may be inappropriate for SRT planning. Meanwhile, CCC and SP were close to XVMC simulations and actual dose distributions obtained in lung SRT.
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Affiliation(s)
- Wataru Takahashi
- Department of Radiology, University of Tokyo Hospital, Hongo, Bunkyo-ku, Tokyo, Japan
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