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Keenan KE, Jordanova KV, Ogier SE, Tamada D, Bruhwiler N, Starekova J, Riek J, McCracken PJ, Hernando D. Phantoms for Quantitative Body MRI: a review and discussion of the phantom value. MAGMA (NEW YORK, N.Y.) 2024:10.1007/s10334-024-01181-8. [PMID: 38896407 DOI: 10.1007/s10334-024-01181-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2023] [Revised: 05/18/2024] [Accepted: 06/11/2024] [Indexed: 06/21/2024]
Abstract
In this paper, we review the value of phantoms for body MRI in the context of their uses for quantitative MRI methods research, clinical trials, and clinical imaging. Certain uses of phantoms are common throughout the body MRI community, including measuring bias, assessing reproducibility, and training. In addition to these uses, phantoms in body MRI methods research are used for novel methods development and the design of motion compensation and mitigation techniques. For clinical trials, phantoms are an essential part of quality management strategies, facilitating the conduct of ethically sound, reliable, and regulatorily compliant clinical research of both novel MRI methods and therapeutic agents. In the clinic, phantoms are used for development of protocols, mitigation of cost, quality control, and radiotherapy. We briefly review phantoms developed for quantitative body MRI, and finally, we review open questions regarding the most effective use of a phantom for body MRI.
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Affiliation(s)
- Kathryn E Keenan
- Physical Measurement Laboratory, National Institute of Standards and Technology, NIST, 325 Broadway, Boulder, CO, 80305, USA.
| | - Kalina V Jordanova
- Physical Measurement Laboratory, National Institute of Standards and Technology, NIST, 325 Broadway, Boulder, CO, 80305, USA
| | - Stephen E Ogier
- Physical Measurement Laboratory, National Institute of Standards and Technology, NIST, 325 Broadway, Boulder, CO, 80305, USA
- Department of Physics, University of Colorado Boulder, Boulder, CO, USA
| | | | - Natalie Bruhwiler
- Physical Measurement Laboratory, National Institute of Standards and Technology, NIST, 325 Broadway, Boulder, CO, 80305, USA
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Warren M, Barrett A, Bhalla N, Brada M, Chuter R, Cobben D, Eccles CL, Hart C, Ibrahim E, McClelland J, Rea M, Turtle L, Fenwick JD. Sorting lung tumor volumes from 4D-MRI data using an automatic tumor-based signal reduces stitching artifacts. J Appl Clin Med Phys 2024; 25:e14262. [PMID: 38234116 PMCID: PMC11005973 DOI: 10.1002/acm2.14262] [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: 08/31/2023] [Revised: 10/30/2023] [Accepted: 12/18/2023] [Indexed: 01/19/2024] Open
Abstract
PURPOSE To investigate whether a novel signal derived from tumor motion allows more precise sorting of 4D-magnetic resonance (4D-MR) image data than do signals based on normal anatomy, reducing levels of stitching artifacts within sorted lung tumor volumes. METHODS (4D-MRI) scans were collected for 10 lung cancer patients using a 2D T2-weighted single-shot turbo spin echo sequence, obtaining 25 repeat frames per image slice. For each slice, a tumor-motion signal was generated using the first principal component of movement in the tumor neighborhood (TumorPC1). Signals were also generated from displacements of the diaphragm (DIA) and upper and lower chest wall (UCW/LCW) and from slice body area changes (BA). Pearson r coefficients of correlations between observed tumor movement and respiratory signals were determined. TumorPC1, DIA, and UCW signals were used to compile image stacks showing each patient's tumor volume in a respiratory phase. Unsorted image stacks were also built for comparison. For each image stack, the presence of stitching artifacts was assessed by measuring the roughness of the compiled tumor surface according to a roughness metric (Rg). Statistical differences in weighted means of Rg between any two signals were determined using an exact permutation test. RESULTS The TumorPC1 signal was most strongly correlated with superior-inferior tumor motion, and had significantly higher Pearson r values (median 0.86) than those determined for correlations of UCW, LCW, and BA with superior-inferior tumor motion (p < 0.05). Weighted means of ratios of Rg values in TumorPC1 image stacks to those in unsorted, UCW, and DIA stacks were 0.67, 0.69, and 0.71, all significantly favoring TumorPC1 (p = 0.02-0.05). For other pairs of signals, weighted mean ratios did not differ significantly from one. CONCLUSION Tumor volumes were smoother in 3D image stacks compiled using the first principal component of tumor motion than in stacks compiled with signals based on normal anatomy.
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Affiliation(s)
- Mark Warren
- School of Health Sciences, Institute of Population HealthUniversity of LiverpoolLiverpoolUK
| | | | - Neeraj Bhalla
- The Clatterbridge Cancer Centre NHS Foundation TrustLiverpoolUK
| | - Michael Brada
- Molecular & Clinical Cancer Medicine, Institute of Institute of Systems, Molecular and Integrative BiologyUniversity of LiverpoolLiverpoolUK
| | - Robert Chuter
- Christie Medical Physics and EngineeringThe Christie NHS Foundation TrustManchesterUK
- Division of Cancer Sciences, School of Medical Sciences, Faculty of Biology, Medicine and HealthUniversity of ManchesterManchesterUK
| | - David Cobben
- The Clatterbridge Cancer Centre NHS Foundation TrustLiverpoolUK
- Department of Health Data Science, Institute of Population HealthUniversity of LiverpoolLiverpoolUK
| | - Cynthia L. Eccles
- Division of Cancer Sciences, School of Medical Sciences, Faculty of Biology, Medicine and HealthUniversity of ManchesterManchesterUK
- RadiotherapyThe Christie NHS Foundation TrustManchesterUK
| | - Clare Hart
- The Clatterbridge Cancer Centre NHS Foundation TrustLiverpoolUK
| | - Ehab Ibrahim
- The Clatterbridge Cancer Centre NHS Foundation TrustLiverpoolUK
| | - Jamie McClelland
- Department of Medical Physics and BioengineeringUniversity College LondonLondonUK
| | - Marc Rea
- The Clatterbridge Cancer Centre NHS Foundation TrustLiverpoolUK
| | - Louise Turtle
- The Clatterbridge Cancer Centre NHS Foundation TrustLiverpoolUK
| | - John D. Fenwick
- Department of Medical Physics and BioengineeringUniversity College LondonLondonUK
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Fast MF, Cao M, Parikh P, Sonke JJ. Intrafraction Motion Management With MR-Guided Radiation Therapy. Semin Radiat Oncol 2024; 34:92-106. [PMID: 38105098 DOI: 10.1016/j.semradonc.2023.10.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2023]
Abstract
High quality radiation therapy requires highly accurate and precise dose delivery. MR-guided radiotherapy (MRgRT), integrating an MRI scanner with a linear accelerator, offers excellent quality images in the treatment room without subjecting patient to ionizing radiation. MRgRT therefore provides a powerful tool for intrafraction motion management. This paper summarizes different sources of intrafraction motion for different disease sites and describes the MR imaging techniques available to visualize and quantify intrafraction motion. It provides an overview of MR guided motion management strategies and of the current technical capabilities of the commercially available MRgRT systems. It describes how these motion management capabilities are currently being used in clinical studies, protocols and provides a future outlook.
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Affiliation(s)
- Martin F Fast
- Department of Radiotherapy, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Minsong Cao
- Department of Radiation Oncology, University of California, Los Angeles, CA
| | - Parag Parikh
- Department of Radiation Oncology, Henry Ford Health - Cancer, Detroit, MI
| | - Jan-Jakob Sonke
- Department of Radiation Oncology, The Netherlands Cancer Institute, Amsterdam, The Netherlands.
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Riis HL, Chick J, Dunlop A, Tilly D. The Quality Assurance of a 1.5 T MR-Linac. Semin Radiat Oncol 2024; 34:120-128. [PMID: 38105086 DOI: 10.1016/j.semradonc.2023.10.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2023]
Abstract
The recent introduction of a commercial 1.5 T MR-linac system has considerably improved the image quality of the patient acquired in the treatment unit as well as enabling online adaptive radiation therapy (oART) treatment strategies. Quality Assurance (QA) of this new technology requires new methodology that allows for the high field MR in a linac environment. The presence of the magnetic field requires special attention to the phantoms, detectors, and tools to perform QA. Due to the design of the system, the integrated megavoltage imager (MVI) is essential for radiation beam calibrations and QA. Additionally, the alignment between the MR image system and the radiation isocenter must be checked. The MR-linac system has vendor-supplied phantoms for calibration and QA tests. However, users have developed their own routine QA systems to independently check that the machine is performing as required, as to ensure we are able to deliver the intended dose with sufficient certainty. The aim of this work is therefore to review the MR-linac specific QA procedures reported in the literature.
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Affiliation(s)
- Hans Lynggaard Riis
- Department of Oncology, Odense University Hospital, Odense, Denmark; Department of Clinical Research, University of Southern Denmark, Odense, Denmark.
| | - Joan Chick
- The Joint Department of Physics, The Royal Marsden Hospital and the Institute of Cancer Research, London, UK
| | - Alex Dunlop
- The Joint Department of Physics, The Royal Marsden Hospital and the Institute of Cancer Research, London, UK
| | - David Tilly
- Department of Immunology, Genetics and Pathology, Medical Radiation Physics, Uppsala University, Uppsala, Sweden; Medical Physics, Uppsala University Hospital, Uppsala, Sweden
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Xiao H, Han X, Zhi S, Wong YL, Liu C, Li W, Liu W, Wang W, Zhang Y, Wu H, Lee HFV, Cheung LYA, Chang HC, Liao YP, Deng J, Li T, Cai J. Ultra-fast multi-parametric 4D-MRI image reconstruction for real-time applications using a downsampling-invariant deformable registration (D2R) model. Radiother Oncol 2023; 189:109948. [PMID: 37832790 DOI: 10.1016/j.radonc.2023.109948] [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: 02/28/2023] [Revised: 09/12/2023] [Accepted: 10/09/2023] [Indexed: 10/15/2023]
Abstract
BACKGROUND AND PURPOSE Motion estimation from severely downsampled 4D-MRI is essential for real-time imaging and tumor tracking. This simulation study developed a novel deep learning model for simultaneous MR image reconstruction and motion estimation, named the Downsampling-Invariant Deformable Registration (D2R) model. MATERIALS AND METHODS Forty-three patients undergoing radiotherapy for liver tumors were recruited for model training and internal validation. Five prospective patients from another center were recruited for external validation. Patients received 4D-MRI scans and 3D MRI scans. The 4D-MRI was retrospectively down-sampled to simulate real-time acquisition. Motion estimation was performed using the proposed D2R model. The accuracy and robustness of the proposed D2R model and baseline methods, including Demons, Elastix, the parametric total variation (pTV) algorithm, and VoxelMorph, were compared. High-quality (HQ) 4D-MR images were also constructed using the D2R model for real-time imaging feasibility verification. The image quality and motion accuracy of the constructed HQ 4D-MRI were evaluated. RESULTS The D2R model showed significantly superior and robust registration performance than all the baseline methods at downsampling factors up to 500. HQ T1-weighted and T2-weighted 4D-MR images were also successfully constructed with significantly improved image quality, sub-voxel level motion error, and real-time efficiency. External validation demonstrated the robustness and generalizability of the technique. CONCLUSION In this study, we developed a novel D2R model for deformation estimation of downsampled 4D-MR images. HQ 4D-MR images were successfully constructed using the D2R model. This model may expand the clinical implementation of 4D-MRI for real-time motion management during liver cancer treatment.
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Affiliation(s)
- Haonan Xiao
- Department of Health Technology and Informatics, The Hong Kong Polytechnic University, Hong Kong, China 999077; Department of Radiation Oncology and Physics, Shandong Cancer Hospital and Institute, Shandong First Medical University and Shandong Academy of Medical Sciences, Jinan, Shandong 250117, China.
| | - Xinyang Han
- Department of Health Technology and Informatics, The Hong Kong Polytechnic University, Hong Kong, China 999077
| | - Shaohua Zhi
- Department of Health Technology and Informatics, The Hong Kong Polytechnic University, Hong Kong, China 999077
| | - Yat-Lam Wong
- Department of Health Technology and Informatics, The Hong Kong Polytechnic University, Hong Kong, China 999077
| | - Chenyang Liu
- Department of Health Technology and Informatics, The Hong Kong Polytechnic University, Hong Kong, China 999077
| | - Wen Li
- Department of Health Technology and Informatics, The Hong Kong Polytechnic University, Hong Kong, China 999077
| | - Weiwei Liu
- Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing), Department of Radiation Oncology, Beijing Cancer Hospital & Institute, Peking University Cancer Hospital & Institute, Beijing 100000, China
| | - Weihu Wang
- Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing), Department of Radiation Oncology, Beijing Cancer Hospital & Institute, Peking University Cancer Hospital & Institute, Beijing 100000, China
| | - Yibao Zhang
- Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing), Department of Radiation Oncology, Beijing Cancer Hospital & Institute, Peking University Cancer Hospital & Institute, Beijing 100000, China
| | - Hao Wu
- Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing), Department of Radiation Oncology, Beijing Cancer Hospital & Institute, Peking University Cancer Hospital & Institute, Beijing 100000, China
| | - Ho-Fun Victor Lee
- Department of Clinical Oncology, The University of Hong Kong, Hong Kong, China 999077
| | - Lai-Yin Andy Cheung
- Department of Clinical Oncology, The University of Hong Kong, Hong Kong, China 999077
| | - Hing-Chiu Chang
- Department of Biomedical Engineering, The Chinese University of Hong Kong, Hong Kong, China 999077
| | - Yen-Peng Liao
- Department of Radiation Oncology's Division of Medical Physics & Engineering, University of Texas Southwestern Medical Center, Texas 75390, USA
| | - Jie Deng
- Department of Radiation Oncology's Division of Medical Physics & Engineering, University of Texas Southwestern Medical Center, Texas 75390, USA
| | - Tian Li
- Department of Health Technology and Informatics, The Hong Kong Polytechnic University, Hong Kong, China 999077.
| | - Jing Cai
- Department of Health Technology and Informatics, The Hong Kong Polytechnic University, Hong Kong, China 999077.
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Ghareeb F, Boukerroui D, Stroom J, Jackson E, Pereira M, Gooding M, Greco C. An approach to generate synthetic 4DCT datasets to benchmark Mid-Position implementations. Phys Med 2023; 114:103144. [PMID: 37778207 DOI: 10.1016/j.ejmp.2023.103144] [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: 09/27/2022] [Revised: 07/14/2023] [Accepted: 09/21/2023] [Indexed: 10/03/2023] Open
Abstract
PURPOSE The Mid-Position image is constructed from 4DCT data using Deformable Image Registration and can be used as planning CT with reduced PTV volumes. 4DCT datasets currently-available for testing do not provide the corresponding Mid-P images of the datasets. This work describes an approach to generate human-like synthetic 4DCT datasets with the associated Mid-P images that can be used as reference in the validation of Mid-P implementations. METHODS Twenty synthetic 4DCT datasets with the associated reference Mid-P images were generated from twenty clinical 4DCT datasets. Per clinical dataset, an anchor phase was registered to the remaining nine phases to obtain nine Deformable Vector Fields (DVFs). These DVFs were used to warp the anchor phase in order to generate the synthetic 4DCT dataset and the corresponding reference Mid-P image. Similarly, a reference 4D tumor mask dataset and its corresponding Mid-P tumor mask were generated. The generated synthetic datasets and masks were used to compare and benchmark the outcomes of three independent Mid-P implementations using a set of experiments. RESULTS The Mid-P images constructed by the three implementations showed high similarity scores when compared to the reference Mid-P images except for one noisy dataset. The biggest difference in the estimated motion amplitudes (-2.6 mm) was noticed in the Superior-Inferior direction. The statistical analysis showed no significant differences among the three implementations for all experiments. CONCLUSION The described approach and the proposed experiments provide an independent method that can be used in the validation of any Mid-P implementation being developed.
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Affiliation(s)
- Firass Ghareeb
- Champalimaud Foundation, Department of Radiation Oncology, Lisbon, Portugal
| | | | - Joep Stroom
- Champalimaud Foundation, Department of Radiation Oncology, Lisbon, Portugal.
| | | | - Mariana Pereira
- Champalimaud Foundation, Department of Radiation Oncology, Lisbon, Portugal
| | | | - Carlo Greco
- Champalimaud Foundation, Department of Radiation Oncology, Lisbon, Portugal
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Tadimalla S, Wang W, Haworth A. Role of Functional MRI in Liver SBRT: Current Use and Future Directions. Cancers (Basel) 2022; 14:cancers14235860. [PMID: 36497342 PMCID: PMC9739660 DOI: 10.3390/cancers14235860] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2022] [Revised: 11/23/2022] [Accepted: 11/24/2022] [Indexed: 11/30/2022] Open
Abstract
Stereotactic body radiation therapy (SBRT) is an emerging treatment for liver cancers whereby large doses of radiation can be delivered precisely to target lesions in 3-5 fractions. The target dose is limited by the dose that can be safely delivered to the non-tumour liver, which depends on the baseline liver functional reserve. Current liver SBRT guidelines assume uniform liver function in the non-tumour liver. However, the assumption of uniform liver function is false in liver disease due to the presence of cirrhosis, damage due to previous chemo- or ablative therapies or irradiation, and fatty liver disease. Anatomical information from magnetic resonance imaging (MRI) is increasingly being used for SBRT planning. While its current use is limited to the identification of target location and size, functional MRI techniques also offer the ability to quantify and spatially map liver tissue microstructure and function. This review summarises and discusses the advantages offered by functional MRI methods for SBRT treatment planning and the potential for adaptive SBRT workflows.
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Affiliation(s)
- Sirisha Tadimalla
- Institute of Medical Physics, School of Physics, Faculty of Science, The University of Sydney, Camperdown, NSW 2006, Australia
- Correspondence:
| | - Wei Wang
- Crown Princess Mary Cancer Centre, Sydney West Radiation Oncology Network, Western Sydney Local Health District, Sydney, NSW 2145, Australia
| | - Annette Haworth
- Institute of Medical Physics, School of Physics, Faculty of Science, The University of Sydney, Camperdown, NSW 2006, Australia
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Contrast-enhanced 4D-MRI for internal target volume generation in treatment planning for liver tumors. Radiother Oncol 2022; 173:69-76. [PMID: 35667575 DOI: 10.1016/j.radonc.2022.05.037] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2022] [Revised: 05/27/2022] [Accepted: 05/31/2022] [Indexed: 11/21/2022]
Abstract
BACKGROUND Liver tumors are often invisible on four-dimensional commuted tomography (4D-CT). Imperfect imaging surrogates are used to estimate the tumor motion. Here, we assessed multiple 4D magnetic resonance (MR) binning algorithms for directly visualizing liver tumor motion for radiotherapy planning. METHODS Patients were simulated using a 3 Tesla MR and CT scanner. Three prototype binning algorithms (phase, amplitude, and two-directional) were applied to the 4D-MRIs, and the image quality was assessed using a qualitative clarity score and quantitative sharpness score. Radiation plans were generated for internal target volumes (ITVs) derived using 4D-MRI and 4D-CT, and the dosimetry of targets were compared. Paired t-tests were used to compare sharpness scores and dosimetric data. RESULTS Twelve patients with 17 liver tumors were scanned between May and November 2021. Compared to phase binning, two-directional demonstrated equal or better clarity and sharpness scores (end-expiration: 0.33 vs. 0.38, p=0.018, end-inspiration: 0.28 vs. 0.31, p=0.010). Compared to amplitude binning, two-directional binning captured hysteresis of ≥3 mm in 35% of patients. Evaluation of dosimetry CT-optimized plans revealed that PTV coverage of MR-derived targets were significantly lower than CT-derived targets (PTV receiving 90% of prescription: 75.56% vs. 89.38%, p=0.002). CONCLUSION Using contrast-enhanced 4D-MRI is feasible for directly delineating liver tumors throughout the respiratory cycle. The current standard of using radiation plans optimized for 4D-CT-derived targets achieved lower coverage of directly visualized MRI targets, suggesting that adopting MRI for motion management may improve radiation treatment of liver lesions and reduce the risk of marginal misses.
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Ligtenberg H, Hackett SL, Merckel LG, Snoeren L, Kontaxis C, Zachiu C, Bol GH, Verhoeff J, Fast MF. Towards mid-position based Stereotactic Body Radiation Therapy on the MR-linac for central lung tumours. Phys Imaging Radiat Oncol 2022; 23:24-31. [PMID: 35923896 PMCID: PMC9341269 DOI: 10.1016/j.phro.2022.05.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Revised: 04/28/2022] [Accepted: 05/04/2022] [Indexed: 11/30/2022] Open
Abstract
Background and purpose: Central lung tumours can be treated by magnetic resonance (MR)-guided radiotherapy. Complications might be reduced by decreasing the Planning Target Volume (PTV) using mid-position (midP)-based planning instead of Internal Target Volume (ITV)-based planning. In this study, we aimed to verify a method to automatically derive patient-specific PTV margins for midP-based planning, and show dosimetric robustness of midP-based planning for a 1.5T MR-linac. Materials and methods: Central(n = 12) and peripheral(n = 4) central lung tumour cases who received 8x7.5 Gy were included. A midP-image was reconstructed from ten phases of the 4D-Computed Tomography using deformable image registration. The Gross Tumor Volume (GTV) was delineated on the midP-image and the PTV margin was automatically calculated based on van Herk’s margin recipe, treating the standard deviation of all Deformation Vector Fields, within the GTV, as random error component. Dosimetric robustness of midP-based planning for MR-linac using automatically derived margins was verified by 4D dose-accumulation. MidP-based plans were compared to ITV-based plans. Automatically derived margins were verified with manually derived margins. Results: The mean D95% target coverage in GTV + 2 mm was 59.9 Gy and 62.0 Gy for midP- and ITV-based central lung plans, respectively. The mean lung dose was significantly lower for midP-based treatment plans (difference:-0.3 Gy; p<0.042). Automatically derived margins agreed within one millimeter with manually derived margins. Conclusions: This retrospective study indicates that mid-position-based treatment plans for central lung Stereotactic Body Radiation Therapy yield lower OAR doses compared to ITV-based treatment plans on the MR-linac. Patient-specific GTV-to-PTV margins can be derived automatically and result in clinically acceptable target coverage.
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Liu C, Li M, Xiao H, Li T, Li W, Zhang J, Teng X, Cai J. Advances in MRI‐guided precision radiotherapy. PRECISION RADIATION ONCOLOGY 2022. [DOI: 10.1002/pro6.1143] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Affiliation(s)
- Chenyang Liu
- Department of Health Technology and Informatics The Hong Kong Polytechnic University Hong Kong SAR China
| | - Mao Li
- Department of Radiation Oncology Philips Healthcare Chengdu China
| | - Haonan Xiao
- Department of Health Technology and Informatics The Hong Kong Polytechnic University Hong Kong SAR China
| | - Tian Li
- Department of Health Technology and Informatics The Hong Kong Polytechnic University Hong Kong SAR China
| | - Wen Li
- Department of Health Technology and Informatics The Hong Kong Polytechnic University Hong Kong SAR China
| | - Jiang Zhang
- Department of Health Technology and Informatics The Hong Kong Polytechnic University Hong Kong SAR China
| | - Xinzhi Teng
- Department of Health Technology and Informatics The Hong Kong Polytechnic University Hong Kong SAR China
| | - Jing Cai
- Department of Health Technology and Informatics The Hong Kong Polytechnic University Hong Kong SAR China
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Technical feasibility and clinical evaluation of 4D-MRI guided liver SBRT on the MR-linac. Radiother Oncol 2022; 167:285-291. [PMID: 35033603 DOI: 10.1016/j.radonc.2022.01.009] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Revised: 12/15/2021] [Accepted: 01/04/2022] [Indexed: 12/22/2022]
Abstract
PURPOSE Image-guided stereotactic body radiation therapy (SBRT) is an important local treatment for liver metastases. MRI-guidance enables direct tumor visualization, eliminating fiducial marker implantation. The purpose of this study was to test technical feasibility of our 4D-MRI guided liver SBRT workflow. Additionally, intra-fraction target motion and consequent target-coverage were studied. MATERIALS&METHODS Patients with liver metastases were included in this sub-study of the prospective UMBRELLA clinical trial. Patients received mid-position (midP) SBRT. The daily adapt-to-position workflow included localization, verification and intra-fraction tumor midP monitoring using 4D-MRI. Technical feasibility was established based on persistence of the treatment protocol, treatment time ≤1 hour, no geographical miss and no unexpected acute toxicity grade >3. All 4D-MRIs were registered to the planning midP-CT and tumor midP and amplitude were calculated. Additionally, delivered target dose was accumulated incorporating the 4D-MRI intra-fraction tumor motion and evaluated with Monte-Carlo error simulations. RESULTS 20 patients with liver metastases were included and treated with 4D-MRI guided SBRT. Feasibility criteria were met in all-but-one patient. No grade ≥3 acute toxicity was observed. Group mean (M), systematic and random midP-drifts were 2.4mm, 2.6mm and 3.1mm in CC-direction. 4D-MRI tumor CC-amplitudes were reduced compared to the simulation 4D-CT (M=-1.9mm) and decreased during treatment (M=-1.4mm). Dose accumulation showed adquate target-coverage on a population level. CONCLUSION We successfully demonstrated technical feasibility of 4D-MRI guided SBRT in a cohort of 20 patients with liver metastases. However, substantial midposition drifts occurred which stress the need for intra-fraction motion management strategies to further increase the precision of treatment delivery.
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Chen Y, Gong G, Wang Y, Liu C, Su Y, Wang L, Yang B, Yin Y. Comparative Evaluation of 4-Dimensional Computed Tomography and 4-Dimensional Magnetic Resonance Imaging to Delineate the Target of Primary Liver Cancer. Technol Cancer Res Treat 2021; 20:15330338211045499. [PMID: 34617855 PMCID: PMC8504652 DOI: 10.1177/15330338211045499] [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] [Indexed: 12/24/2022] Open
Abstract
Purpose: To evaluate the feasibility of 4-dimensional magnetic resonance imaging (4DMRI) in establishing the target of primary liver cancer in comparison with 4-dimensional computed tomography (4DCT). Methods and Materials: A total of 23 patients with primary liver cancer who received radiotherapy were selected, and 4DCT and T2w-4DMRI simulations were conducted to obtain 4DCT and T2w-4DMRI simulation images. The 4DCT and T2w-4DMRI data were sorted into 10 and 8 respiratory phase bins, respectively. The liver and gross tumor volumes (GTVs) were delineated in all images using programmed clinical workflows under tumor delineation guidelines. The internal organs at risk volumes (IRVs) and internal target volumes (ITVs) were the unions of all the phase livers and GTVs, respectively. Then, the artifacts, liver volume, GTV, and motion range in 4DCT and T2w-4DMRI were compared. Results: The mean GTV volume based on 4DMRI was 136.42 ± 231.27 cm3, which was 25.04 cm3 (15.5%) less than that of 4DCT (161.46 ± 280.29 cm3). The average volume of ITV determined by 4DMRI was 166.12 ± 270.43 cm3, which was 22.44 cm3 (11.9%) less than that determined by 4DCT (188.56 ± 307.57 cm3). Liver volume and IRV in 4DMRI increased by 4.0% and 6.6%, respectively, compared with 4DCT. The difference in tumor motion by T2w-4DMRI based on the centroid was greater than that of 4DCT in the L/R, A/P, and S/I directions, and the average displacement differences were 2.6, 2.8, and 6.9 mm, respectively. The severe artifacts in 4DCT were 47.8% (11/23) greater than in 4DMRI 17.4% (4/23). Conclusions: Compared with 4DCT, T2-weighted and navigator-triggered 4DMRI produces fewer artifacts and larger motion differences in hepatic intrafraction tumors, which is a feasible technique for primary liver cancer treatment planning.
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Affiliation(s)
- Yukai Chen
- East China University of Technology, Nanchang, Jiangxi, China
| | - Guanzhong Gong
- Shandong Cancer Hospital and Institute, Shandong First Medical University and Shandong Academy of Medical Sciences, Jinan, Shandong Province, China
| | - Yinxing Wang
- Shandong Cancer Hospital and Institute, Shandong First Medical University and Shandong Academy of Medical Sciences, Jinan, Shandong Province, China
| | - Chenlu Liu
- School of Nuclear Science and Technology, University of South China, Hengyang, China
| | - Ya Su
- Shandong Cancer Hospital and Institute, Shandong First Medical University and Shandong Academy of Medical Sciences, Jinan, Shandong Province, China
| | - Lizhen Wang
- Shandong Cancer Hospital and Institute, Shandong First Medical University and Shandong Academy of Medical Sciences, Jinan, Shandong Province, China
| | - Bo Yang
- East China University of Technology, Nanchang, Jiangxi, China
| | - Yong Yin
- Shandong Cancer Hospital and Institute, Shandong First Medical University and Shandong Academy of Medical Sciences, Jinan, Shandong Province, China
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