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Huang Y, Wang H, Li C, Hu Q, Liu H, Deng J, Li W, Wang R, Wu H, Zhang Y. A Preliminary Simulation Study of Dose-Guided Adaptive Radiotherapy Based on Halcyon MV Cone-Beam CT Images With Retrospective Data From a Phase II Clinical Trial. Front Oncol 2020; 10:574889. [PMID: 33134173 PMCID: PMC7550711 DOI: 10.3389/fonc.2020.574889] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Accepted: 08/17/2020] [Indexed: 01/21/2023] Open
Abstract
Background and purpose: To evaluate the feasibility of dose-guided adaptive radiotherapy (ART) based on deformable image registration (DIR) using fractional megavoltage cone-beam CT (MVCBCT) images from Halcyon system that uses identical beams for treatment and imaging and to retrospectively investigate the influence of anatomic changes on target coverage and organ-at-risk (OAR) sparing across various tumor sites. Materials and Methods: Four hundred twenty-two MVCBCT images from 16 patients (three head and neck, seven thoracic, three abdominal, and three pelvic cases) treated in a phase II clinical trial for Halcyon were selected. DIR between the planning CT and daily MVCBCT image was implemented by Velocity software to create pseudo CT. To investigate the accuracy of dose calculation on pseudo CT, three evaluation patients with rescanned CT and adaptive plans were selected. Dose distribution of adaptive plans calculated on pseudo CT was compared with that calculated on the rescanned planning CT on the three evaluation patients. To investigate the impact of inter-fractional anatomic changes on target dose coverage and dose to OARs of the 16 patients, fractional dose was calculated and accumulated incrementally based on deformable registration between planning CT and daily MVCBCT images. Results: Passing rates using 3 mm/3%/10% threshold local gamma analysis were 93.04, 96.00, and 91.68%, respectively, for the three evaluation patients between the reconstructed dose on pseudo CT (MVCBCT) and rescanned CT, where accumulated dose deviations of over 97% voxels were smaller than 0.5 Gy. Planning target volume (PTV) D95% and D90% (the minimum dose received by at least 95/90% of the volume) of the accumulated dose could be as low as 93.8 and 94.5% of the planned dose, respectively. OAR overdose of various degrees were observed in the 16 patients relative to the planned dose. In most cases, OARs' dose volume histogram (DVH) lines of accumulated and planned dose were very close to each other if not overlapping. Among cases with visible deviations, the differences were bilateral without apparent patterns specific to tumor sites or organs. Conclusion: As a confidence building measure, this simulation study suggested the possibility of ART for Halcyon based on DIR between planning CT and MVCBCT. Preliminary clinical data suggested the benefit of patient-specific dose reconstruction and ART to avoid unacceptable target underdosage and OAR overdosage.
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Affiliation(s)
- Yuliang Huang
- Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing), Department of Radiation Oncology, Peking University Cancer Hospital and Institute, Beijing, China
| | - Haiyang Wang
- Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing), Department of Radiation Oncology, Peking University Cancer Hospital and Institute, Beijing, China
| | - Chenguang Li
- Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing), Department of Radiation Oncology, Peking University Cancer Hospital and Institute, Beijing, China
| | - Qiaoqiao Hu
- Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing), Department of Radiation Oncology, Peking University Cancer Hospital and Institute, Beijing, China
| | - Hongjia Liu
- Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing), Department of Radiation Oncology, Peking University Cancer Hospital and Institute, Beijing, China
| | - Jun Deng
- Department of Therapeutic Radiology, Yale University School of Medicine, New Haven, CT, United States
| | - Weibo Li
- Helmholtz Zentrum München-German Research Center for Environmental Health (GmbH), Institute of Radiation Medicine, Neuherberg, Germany
| | - Ruoxi Wang
- Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing), Department of Radiation Oncology, Peking University Cancer Hospital and Institute, Beijing, China
| | - Hao Wu
- Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing), Department of Radiation Oncology, Peking University Cancer Hospital and Institute, Beijing, China.,Institute of Medical Technology, Peking University Health Science Center, Beijing, China
| | - Yibao Zhang
- Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing), Department of Radiation Oncology, Peking University Cancer Hospital and Institute, Beijing, China.,Institute of Medical Technology, Peking University Health Science Center, Beijing, China
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Huang Y, Li C, Wang H, Hu Q, Wang R, Chang C, Ma W, Li W, Wu H, Zhang Y. A quantitative evaluation of deformable image registration based on MV cone beam CT images: Impact of deformation magnitudes and image modalities. Phys Med 2020; 71:82-87. [PMID: 32097874 DOI: 10.1016/j.ejmp.2020.02.016] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Revised: 02/15/2020] [Accepted: 02/19/2020] [Indexed: 02/03/2023] Open
Abstract
BACKGROUND AND PURPOSE To evaluate the impact of deformation magnitude and image modality on deformable-image-registration (DIR) accuracy using Halcyon megavoltage cone beam CT images (MVCBCT). MATERIALS AND METHODS Planning CT images of an anthropomorphic Head phantom were aligned rigidly with MVCBCT and re-sampled to achieve the same resolution, denoted as pCT. MVCBCT was warped with twenty simulated pre-known virtual deformation fields (Ti, i = 1-20) with increasing deformation magnitudes, yielding warped CBCT (wCBCT). The pCT and MVCBCT were registered to wCBCT respectively (Multi-modality and Uni-modality DIR), generating deformation vector fields Vi and Vi' (i = 1-20). Vi and Vi' were compared with Ti respectively to assess the DIR accuracy geometrically. In addition, Vi, Ti, and Vi' were applied to pCT, generating deformed CT (dCTi), ground-truth CT (Gi) and deformed CT' (dCTi') respectively. The Hounsfield Unit (HU) on these virtual CT images were also compared. RESULTS The mean errors of vector displacement increased with the deformation magnitude. For deformation magnitudes between 2.82 mm and 7.71 mm, the errors of uni-modality DIR were 1.16 mm ~ 1.73 mm smaller than that of multi-modality (p = 0.0001, Wilcoxon signed rank test). DIR could reduce the maximum signed and absolute HU deviations from 70.8 HU to 11.4 HU and 208 HU to 46.2 HU respectively. CONCLUSIONS As deformation magnitude increases, DIR accuracy continues to deteriorate and uni-modality DIR consistently outperformed multi-modality DIR. DIR-based adaptive radiotherapy utilizing the noisy MVCBCT images is only conditionally applicable with caution.
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Affiliation(s)
- Yuliang Huang
- Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing), Department of Radiation Oncology, Peking University Cancer Hospital & Institute, Beijing 100142, China
| | - Chenguang Li
- Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing), Department of Radiation Oncology, Peking University Cancer Hospital & Institute, Beijing 100142, China
| | - Haiyang Wang
- Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing), Department of Radiation Oncology, Peking University Cancer Hospital & Institute, Beijing 100142, China
| | - Qiaoqiao Hu
- Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing), Department of Radiation Oncology, Peking University Cancer Hospital & Institute, Beijing 100142, China
| | - Ruoxi Wang
- Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing), Department of Radiation Oncology, Peking University Cancer Hospital & Institute, Beijing 100142, China
| | - Cheng Chang
- Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing), Department of Radiation Oncology, Peking University Cancer Hospital & Institute, Beijing 100142, China
| | - Wenjun Ma
- State Key Laboratory of Nuclear Physics and Technology, Peking University, Beijing 100871, China
| | - Weibo Li
- Institute of Radiation Medicine, Helmholtz Zentrum München - German Research Center for Environmental Health (GmbH), Ingolstädter Landstr, 85764 Neuherberg, Germany
| | - Hao Wu
- Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing), Department of Radiation Oncology, Peking University Cancer Hospital & Institute, Beijing 100142, China; Institute of Medical Technology, Peking University Health Science Center, Beijing 100191, China.
| | - Yibao Zhang
- Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing), Department of Radiation Oncology, Peking University Cancer Hospital & Institute, Beijing 100142, China; Institute of Medical Technology, Peking University Health Science Center, Beijing 100191, China.
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3
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Shelley LEA, Sutcliffe MPF, Harrison K, Scaife JE, Parker MA, Romanchikova M, Thomas SJ, Jena R, Burnet NG. Autosegmentation of the rectum on megavoltage image guidance scans. Biomed Phys Eng Express 2019; 5:025006. [PMID: 31057946 PMCID: PMC6466640 DOI: 10.1088/2057-1976/aaf1db] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2018] [Revised: 11/07/2018] [Accepted: 11/19/2018] [Indexed: 11/12/2022]
Abstract
Autosegmentation of image guidance (IG) scans is crucial for streamlining and optimising delivered dose calculation in radiotherapy. By accounting for interfraction motion, daily delivered dose can be accumulated and incorporated into automated systems for adaptive radiotherapy. Autosegmentation of IG scans is challenging due to poorer image quality than typical planning kilovoltage computed tomography (kVCT) systems, and the resulting reduction of soft tissue contrast in regions such as the pelvis makes organ boundaries less distinguishable. Current autosegmentation solutions generally involve propagation of planning contours to the IG scan by deformable image registration (DIR). Here, we present a novel approach for primary autosegmentation of the rectum on megavoltage IG scans acquired during prostate radiotherapy, based on the Chan-Vese algorithm. Pre-processing steps such as Hounsfield unit/intensity scaling, identifying search regions, dealing with air, and handling the prostate, are detailed. Post-processing features include identification of implausible contours (nominally those affected by muscle or air), 3D self-checking, smoothing, and interpolation. In cases where the algorithm struggles, the best estimate on a given slice may revert to the propagated kVCT rectal contour. Algorithm parameters were optimised systematically for a training cohort of 26 scans, and tested on a validation cohort of 30 scans, from 10 patients. Manual intervention was not required. Comparing Chan-Vese autocontours with contours manually segmented by an experienced clinical oncologist achieved a mean Dice Similarity Coefficient of 0.78 (SE < 0.011). This was comparable with DIR methods for kVCT and CBCT published in the literature. The autosegmentation system was developed within the VoxTox Research Programme for accumulation of delivered dose to the rectum in prostate radiotherapy, but may have applicability to further anatomical sites and imaging modalities.
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Affiliation(s)
- L E A Shelley
- University of Cambridge, Department of Engineering, Cambridge, United Kingdom
- Addenbrooke's Hospital, Department of Medical Physics and Clinical Engineering, Cambridge, United Kingdom
- Cambridge University Hospitals NHS Foundation Trust, Cancer Research UK VoxTox Research Group, Cambridge, United Kingdom
| | - M P F Sutcliffe
- University of Cambridge, Department of Engineering, Cambridge, United Kingdom
- Cambridge University Hospitals NHS Foundation Trust, Cancer Research UK VoxTox Research Group, Cambridge, United Kingdom
| | - K Harrison
- Cambridge University Hospitals NHS Foundation Trust, Cancer Research UK VoxTox Research Group, Cambridge, United Kingdom
- University of Cambridge, Cavendish Laboratory, Cambridge, United Kingdom
| | - J E Scaife
- Gloucestershire Oncology Centre, Cheltenham General Hospital, Cheltenham, United Kingdom
| | - M A Parker
- Cambridge University Hospitals NHS Foundation Trust, Cancer Research UK VoxTox Research Group, Cambridge, United Kingdom
- University of Cambridge, Cavendish Laboratory, Cambridge, United Kingdom
| | - M Romanchikova
- Cambridge University Hospitals NHS Foundation Trust, Cancer Research UK VoxTox Research Group, Cambridge, United Kingdom
- National Physical Laboratory, Teddington, United Kingdom
| | - S J Thomas
- Addenbrooke's Hospital, Department of Medical Physics and Clinical Engineering, Cambridge, United Kingdom
- Cambridge University Hospitals NHS Foundation Trust, Cancer Research UK VoxTox Research Group, Cambridge, United Kingdom
| | - R Jena
- Cambridge University Hospitals NHS Foundation Trust, Cancer Research UK VoxTox Research Group, Cambridge, United Kingdom
- Addenbrooke's Hospital, Oncology Centre, Cambridge, United Kingdom
| | - N G Burnet
- Cambridge University Hospitals NHS Foundation Trust, Cancer Research UK VoxTox Research Group, Cambridge, United Kingdom
- University of Manchester, Manchester Academic Health Science Centre, Manchester, United Kingdom
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Takemura A, Nagano A, Kojima H, Ikeda T, Yokoyama N, Tsukamoto K, Noto K, Isomura N, Ueda S, Kawashima H. An uncertainty metric to evaluate deformation vector fields for dose accumulation in radiotherapy. PHYSICS & IMAGING IN RADIATION ONCOLOGY 2018; 6:77-82. [PMID: 33458393 PMCID: PMC7807581 DOI: 10.1016/j.phro.2018.05.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/24/2017] [Revised: 05/14/2018] [Accepted: 05/23/2018] [Indexed: 02/08/2023]
Abstract
Background and purpose In adaptive radiotherapy, deformable image registration (DIR) is used to propagate delineations of tumors and organs into a new therapy plan and to calculate the accumulated total dose. Many DIR accuracy metrics have been proposed. An alternative proposed here could be a local uncertainty (LU) metric for DIR results. Materials and methods The LU represented the uncertainty of each DIR position and was focused on deformation evaluation in uniformly-dense regions. Four cases demonstrated LU calculations: two head and neck cancer cases, a lung cancer case, and a prostate cancer case. Each underwent two CT examinations for radiotherapy planning. Results LU maps were calculated from each DIR of the clinical cases. Reduced fat regions had LUs of 4.6 ± 0.9 mm, 4.8 ± 1.0 mm, and 4.5 ± 0.7 mm, while the shrunken left parotid gland had a LU of 4.1 ± 0.8 mm and the shrunken lung tumor had a LU of 3.7 ± 0.7 mm. The bowels in the pelvic region had a LU of 10.2 ± 3.7 mm. LU histograms for the cases were similar and 99% of the voxels had a LU < 3 mm. Conclusions LU is a new uncertainty metric for DIR that was demonstrated for clinical cases. It had a tolerance of <3 mm.
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Affiliation(s)
- Akihiro Takemura
- Faculty of Health Sciences, Institution of Medical, Pharmaceutical and Health Sciences, Kanazawa University, 5-11-80 Kodatsuno, Kanazawa 920-0942, Japan
| | - Akira Nagano
- Division of Radiology, Okayama University Hospital, 2-5-1 Shikatacho, Kitaku, Okayama 700-8558, Japan
| | - Hironori Kojima
- Department of Radiological Technology, Kanazawa University Hospital, 13-1 Takaramachi, Kanazawa 920-8641, Japan.,Division of Health Sciences, Graduate School of Medical Sciences, Kanazawa University, 5-11-80 Kodatsuno, Kanazawa 920-0942, Japan
| | - Tomohiro Ikeda
- Department of Radiation Oncology, Southern Tohoku Proton Therapy Center, 7-115 Yatsuyamada, Koriyama-City, Fukushima-Pref. 963-8563, Japan
| | - Noriomi Yokoyama
- Division of Health Sciences, Graduate School of Medical Sciences, Kanazawa University, 5-11-80 Kodatsuno, Kanazawa 920-0942, Japan
| | - Kosuke Tsukamoto
- Department of Radiological Technology, Kanazawa University Hospital, 13-1 Takaramachi, Kanazawa 920-8641, Japan
| | - Kimiya Noto
- Department of Radiological Technology, Kanazawa University Hospital, 13-1 Takaramachi, Kanazawa 920-8641, Japan
| | - Naoki Isomura
- Department of Radiological Technology, Kanazawa University Hospital, 13-1 Takaramachi, Kanazawa 920-8641, Japan
| | - Shinichi Ueda
- Department of Radiological Technology, Kanazawa University Hospital, 13-1 Takaramachi, Kanazawa 920-8641, Japan
| | - Hiroki Kawashima
- Faculty of Health Sciences, Institution of Medical, Pharmaceutical and Health Sciences, Kanazawa University, 5-11-80 Kodatsuno, Kanazawa 920-0942, Japan
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Tsai YL, Wu CJ, Shaw S, Yu PC, Nien HH, Lui LT. Quantitative analysis of respiration-induced motion of each liver segment with helical computed tomography and 4-dimensional computed tomography. Radiat Oncol 2018; 13:59. [PMID: 29609631 PMCID: PMC5879734 DOI: 10.1186/s13014-018-1007-0] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Accepted: 03/22/2018] [Indexed: 12/16/2022] Open
Abstract
Background To analyze the respiratory-induced motion of each liver segment using helical computed tomography (helical CT) and 4-dimensional computed tomography (4DCT), and to establish the individual segment expansion margin of internal target volume (ITV) to facilitate target delineation of tumors in different liver segments. Methods Twenty patients who received radiotherapy with CT-simulation scanning of the whole liver in both helical CT and 10-phase-gated 4DCT were investigated, including 2 patients with esophagus cancer, 4 with lung cancer, 10 with breast cancer, 2 with liver cancer, 1 with thymoma, and 1 with gastric diffuse large B-cell lymphoma (DLBCL). For each patient, 9 representative points were drawn on the helical CT images of liver segments 1, 2, 3, 4a, 4b, 5, 6, 7, and 8, respectively, and adaptively deformed to 2 phases of the 4DCT images at the end of inspiration (phase 0 CT) and expiration (phase 50 CT) in the treatment planning system. Using the amplitude of each point between phase 0 CT and phase 50 CT, we established quantitative data for the respiration-induced motion of each liver segment in 3-dimensional directions. Moreover, using the amplitude between the original helical CT and both 4DCT images, we rendered the individual segment expansion margin of ITV for hepatic target delineation to cover more than 95% of each tumor. Results The average amplitude (mean ± standard deviation) was 0.6 ± 3.0 mm in the left-right (LR) direction, 2.3 ± 2.4 mm in the anterior-posterior (AP) direction, and 5.7 ± 3.4 mm in the superior-inferior (SI) direction, respectively. All of the segments moved posteriorly and superiorly during expiration. Segment 7 had the largest amplitude in the SI direction, at 8.6 ± 3.4 mm. Otherwise, the segments over the lateral side, including segments 2, 3, 6, and 7, had greater excursion in the SI direction compared to the medial segments. To cover more than 95% of each tumor, the required expansion margin of ITV in the LR, AP, and SI directions were at least 2.5 mm, 2.5 mm, and 5.0 mm on average, respectively, with variations between different segments. Conclusions The greatest excursion occurred in liver segment 7, followed by the segments over the lateral side in the SI direction. The individual segment expansion margin of ITV is required to delineate targets for each segment and direction.
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Affiliation(s)
- Yu-Lun Tsai
- Department of Radiation Oncology, Cathay General Hospital, Taipei, Taiwan
| | - Ching-Jung Wu
- Department of Radiation Oncology, Cathay General Hospital, Taipei, Taiwan.,Department of Radiation Oncology, National Defense Medical Center, Taipei, Taiwan.,Department of Biomedical Engineering, I-Shou University, Kaohsiung, Taiwan
| | - Suzun Shaw
- Department of Radiation Oncology, Cathay General Hospital, Taipei, Taiwan
| | - Pei-Chieh Yu
- Department of Radiation Oncology, Cathay General Hospital, Taipei, Taiwan
| | - Hsin-Hua Nien
- Department of Radiation Oncology, Cathay General Hospital, Taipei, Taiwan
| | - Louis Tak Lui
- Department of Radiation Oncology, Cathay General Hospital, Taipei, Taiwan.
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Kim H, Chen J, Phillips J, Pukala J, Yom SS, Kirby N. Validating Dose Uncertainty Estimates Produced by AUTODIRECT: An Automated Program to Evaluate Deformable Image Registration Accuracy. Technol Cancer Res Treat 2017; 16:885-892. [PMID: 28490254 PMCID: PMC5762045 DOI: 10.1177/1533034617708076] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2016] [Revised: 02/27/2017] [Accepted: 03/22/2017] [Indexed: 11/17/2022] Open
Abstract
Deformable image registration is a powerful tool for mapping information, such as radiation therapy dose calculations, from one computed tomography image to another. However, deformable image registration is susceptible to mapping errors. Recently, an automated deformable image registration evaluation of confidence tool was proposed to predict voxel-specific deformable image registration dose mapping errors on a patient-by-patient basis. The purpose of this work is to conduct an extensive analysis of automated deformable image registration evaluation of confidence tool to show its effectiveness in estimating dose mapping errors. The proposed format of automated deformable image registration evaluation of confidence tool utilizes 4 simulated patient deformations (3 B-spline-based deformations and 1 rigid transformation) to predict the uncertainty in a deformable image registration algorithm's performance. This workflow is validated for 2 DIR algorithms (B-spline multipass from Velocity and Plastimatch) with 1 physical and 11 virtual phantoms, which have known ground-truth deformations, and with 3 pairs of real patient lung images, which have several hundred identified landmarks. The true dose mapping error distributions closely followed the Student t distributions predicted by automated deformable image registration evaluation of confidence tool for the validation tests: on average, the automated deformable image registration evaluation of confidence tool-produced confidence levels of 50%, 68%, and 95% contained 48.8%, 66.3%, and 93.8% and 50.1%, 67.6%, and 93.8% of the actual errors from Velocity and Plastimatch, respectively. Despite the sparsity of landmark points, the observed error distribution from the 3 lung patient data sets also followed the expected error distribution. The dose error distributions from automated deformable image registration evaluation of confidence tool also demonstrate good resemblance to the true dose error distributions. Automated deformable image registration evaluation of confidence tool was also found to produce accurate confidence intervals for the dose-volume histograms of the deformed dose.
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Affiliation(s)
- Hojin Kim
- Department of Radiation Oncology, University of California, San Francisco, CA, USA
- Department of Radiation Oncology, Asan Medical Center, University of Uslan College of Medicine, Seoul, Korea
| | - Josephine Chen
- Department of Radiation Oncology, University of California, San Francisco, CA, USA
| | - Justin Phillips
- Department of Radiation Oncology, University of California, San Francisco, CA, USA
| | - Jason Pukala
- Department of Radiation Oncology, University of Florida Health Cancer Center at Orlando Health, Orlando, FL, USA
| | - Sue S. Yom
- Department of Radiation Oncology, University of California, San Francisco, CA, USA
| | - Neil Kirby
- Department of Radiation Oncology, University of Texas Health Science Center San Antonio, San Antonio, TX, USA
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Sugawara Y, Tachibana H, Kadoya N, Kitamura N, Sawant A, Jingu K. Prognostic factors associated with the accuracy of deformable image registration in lung cancer patients treated with stereotactic body radiotherapy. Med Dosim 2017; 42:326-333. [PMID: 28802976 DOI: 10.1016/j.meddos.2017.07.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2016] [Revised: 03/28/2017] [Accepted: 07/03/2017] [Indexed: 11/19/2022]
Abstract
We evaluated the accuracy of an in-house program in lung stereotactic body radiation therapy (SBRT) cancer patients, and explored the prognostic factors associated with the accuracy of deformable image registrations (DIRs). The accuracy of the 3 programs which implement the free-form deformation and the B-spline algorithm was compared regarding the structures on 4-dimensional computed tomography (4DCT) image datasets between the peak-inhale and peak-exhale phases. The dice similarity coefficient (DSC) and normalized DSC (NDSC) were measured for the gross tumor volumes from 19 lung SBRT patients. We evaluated the accuracy of DIR using gross tumor volume, magnitude of displacement from 0% phase to 50% phase, whole lung volume in the 50% phase image, and status of tumor pleural attachment. The median NDSC values using the NiftyReg, MIM Maestro and Velocity AI programs were 1.027, 1.005, and 0.946, respectively, indicating that NiftyReg and MIM Maestro programs had similar accuracy with an uncertainty of < 1 mm. Larger uncertainty of 1 to 2 mm was observed using the Velocity AI program. The NiftyReg and the MIM programs provided higher NDSC values than the median values when the gross tumor volume was attached to the pleura (p <0.05). However, it showed a different trend in using the Velocity AI program. All software programs provided unexpected results, and there is a possibility that such results would reduce the accuracy of 4D treatment planning and adaptive radiotherapy. The unexpected results may be because the tumors are surrounded by other tissues, and there are differences regarding the region of interest for rigid and nonrigid registration. Furthermore, our results indicated that the pleural attachment status might be an important predictor of DIR accuracy for thoracic images, indicating that there is a potentially large dose distribution discrepancy concerning 4D treatment planning and adaptive radiotherapy.
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Affiliation(s)
- Yasuharu Sugawara
- Department of Radiology, National Center for Global Health and Medicine, Tokyo, Japan; Department of Radiation Oncology, Tohoku University Graduate School of Medicine, Miyagi, Japan
| | - Hidenobu Tachibana
- Particle Therapy Division, Research Center for Innovative Oncology, National Cancer Center Hospital East, Chiba, Japan.
| | - Noriyuki Kadoya
- Department of Radiation Oncology, Tohoku University Graduate School of Medicine, Miyagi, Japan
| | - Nozomi Kitamura
- Department of Radiation Oncology, Cancer Institute Hospital of the Japanese Foundation of Cancer Research, Tokyo, Japan
| | - Amit Sawant
- Department of Radiation Oncology, University of Texas Southwestern Medical Center, Texas, USA
| | - Keiichi Jingu
- Department of Radiation Oncology, Tohoku University Graduate School of Medicine, Miyagi, Japan
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8
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Abe Y, Kadoya N, Arai K, Takayama Y, Kato T, Kimura K, Ono T, Nakamura T, Wada H, Kikuchi Y, Jingu K. Effect of DIR uncertainty on prostate passive-scattering proton therapy dose accumulation. Phys Med 2017. [DOI: 10.1016/j.ejmp.2017.06.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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Moriya S, Tachibana H, Kitamura N, Sawant A, Sato M. Dose warping performance in deformable image registration in lung. Phys Med 2017; 37:16-23. [DOI: 10.1016/j.ejmp.2017.03.016] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/14/2016] [Revised: 02/13/2017] [Accepted: 03/20/2017] [Indexed: 10/19/2022] Open
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Moulton CR, House MJ, Lye V, Tang CI, Krawiec M, Joseph DJ, Denham JW, Ebert MA. Prostate external beam radiotherapy combined with high-dose-rate brachytherapy: dose-volume parameters from deformably-registered plans correlate with late gastrointestinal complications. Radiat Oncol 2016; 11:144. [PMID: 27799048 PMCID: PMC5087115 DOI: 10.1186/s13014-016-0719-2] [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: 07/28/2016] [Accepted: 10/17/2016] [Indexed: 01/05/2023] Open
Abstract
BACKGROUND Derivation of dose-volume correlated with toxicity for multi-modal treatments can be difficult due to the perceived need for voxel-by-voxel dose accumulation. With data available for a single-institution cohort with long follow-up, an investigation was undertaken into rectal dose-volume effects for gastrointestinal toxicities after deformably-registering each phase of a combined external beam radiotherapy (EBRT)/high-dose-rate (HDR) brachytherapy prostate treatment. METHODS One hundred and eighteen patients received EBRT in 23 fractions of 2 Gy and HDR (TG43 algorithm) in 3 fractions of 6.5 Gy. Results for the Late Effects of Normal Tissues - Subjective, Objective, Management and Analytic toxicity assessments were available with a median follow-up of 72 months. The HDR CT was deformably-registered to the EBRT CT. Doses were corrected for dose fractionation. Rectum dose-volume histogram (DVH) parameters were calculated in two ways. (1) Distribution-adding: parameters were calculated after the EBRT dose distribution was 3D-summed with the registered HDR dose distribution. (2) Parameter-adding: the EBRT DVH parameters were added to HDR DVH parameters. Logistic regressions and Mann-Whitney U-tests were used to correlate parameters with late peak toxicity (dichotomised at grade 1 or 2). RESULTS The 48-80, 40-63 and 49-55 Gy dose regions from distribution-adding were significantly correlated with rectal bleeding, urgency/tenesmus and stool frequency respectively. Additionally, urgency/tenesmus and anorectal pain were associated with the 25-26 Gy and 44-48 Gy dose regions from distribution-adding respectively. Parameter-adding also indicated the low-mid dose region was significantly correlated with stool frequency and proctitis. CONCLUSIONS This study confirms significant dose-histogram effects for gastrointestinal toxicities after including deformable registration to combine phases of EBRT/HDR prostate cancer treatment. The findings from distribution-adding were in most cases consistent with those from parameter-adding. The mid-high dose range and near maximum doses were important for rectal bleeding. The distribution-adding mid-high dose range was also important for stool frequency and urgency/tenesmus. We encourage additional studies in a variety of institutions using a variety of dose accumulation methods with appropriate inter-fraction motion management. TRIAL REGISTRATION NCT NCT00193856 . Retrospectively registered 12 September 2005.
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Affiliation(s)
- Calyn R. Moulton
- School of Physics (M013), University of Western Australia, 35 Stirling Highway, Crawley, WA 6009 Australia
| | - Michael J. House
- School of Physics (M013), University of Western Australia, 35 Stirling Highway, Crawley, WA 6009 Australia
| | - Victoria Lye
- Radiation Oncology, Sir Charles Gairdner Hospital, Hospital Avenue, Nedlands, WA 6009 Australia
| | - Colin I. Tang
- Radiation Oncology, Sir Charles Gairdner Hospital, Hospital Avenue, Nedlands, WA 6009 Australia
| | - Michele Krawiec
- Radiation Oncology, Sir Charles Gairdner Hospital, Hospital Avenue, Nedlands, WA 6009 Australia
| | - David J. Joseph
- Radiation Oncology, Sir Charles Gairdner Hospital, Hospital Avenue, Nedlands, WA 6009 Australia
- School of Surgery, University of Western Australia, 35 Stirling Highway, Crawley, WA 6009 Australia
| | - James W. Denham
- School of Medicine and Population Health, University of Newcastle, University Drive, Callaghan, NSW 2308 Australia
| | - Martin A. Ebert
- School of Physics (M013), University of Western Australia, 35 Stirling Highway, Crawley, WA 6009 Australia
- Radiation Oncology, Sir Charles Gairdner Hospital, Hospital Avenue, Nedlands, WA 6009 Australia
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11
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Rosewall T, Wheat J, Currie G, Kong V, Bayley AJ, Moseley J, Chung P, Catton C, Craig T, Milosevic M. Planned versus 'delivered' bladder dose reconstructed using solid and hollow organ models during prostate cancer IMRT. Radiother Oncol 2016; 119:417-22. [PMID: 27072936 DOI: 10.1016/j.radonc.2016.03.022] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2016] [Revised: 03/11/2016] [Accepted: 03/13/2016] [Indexed: 10/22/2022]
Abstract
BACKGROUND AND PURPOSE All studies to date have evaluated the dosimetric effect of bladder deformation using an organ model that includes the dose to the urine. This research reconstructed bladder dose using both hollow and solid organ models, to determine if dose/volume differences exist. MATERIALS AND METHODS 35 prostate IMRT patients were selected, who had received 78Gy in 39 fractions and full bladder instructions. Biomechanical modelling and finite element analysis were used to reconstruct bladder dose (solid and hollow organ model) using every third CBCT throughout the treatment course. RESULTS Reconstructed dose (ReconDose) was 11.3Gy greater than planned dose (planDose) with a hollow bladder model (p<0.001) and 12.3Gy greater with a solid bladder model (p<0.0001). Median reconstructed volumes within the 30Gy, 65Gy and 78Gy isodoses were 3-4 times larger with the solid organ model (p<0.0001). The difference between planning bladder volume and median treatment volume was associated with the difference between the planDose and reconDose below 78Gy (R(2)>0.61). CONCLUSIONS Substantial differences exist between planned and reconstructed bladder dose, associated with the differences in bladder filling between planning and treatment. Dose reconstructed using a solid bladder model over-reports the volume of bladder within key isodose levels and overestimates the differences between planned and reconstructed dose. Dose reconstruction with a hollow organ model is recommended if the goal is to associate that dose with toxicity.
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Affiliation(s)
- Tara Rosewall
- Radiation Medicine Program, Princess Margaret Cancer Centre, Toronto, Canada; Department of Radiation Oncology, University of Toronto, Canada; Faculty of Science, Charles Sturt University, Australia.
| | - Janelle Wheat
- Faculty of Science, Charles Sturt University, Australia; Faculty of Medicine and Health Sciences, Macquarie University, Australia
| | - Geoffrey Currie
- Faculty of Science, Charles Sturt University, Australia; Faculty of Medicine and Health Sciences, Macquarie University, Australia
| | - Vickie Kong
- Radiation Medicine Program, Princess Margaret Cancer Centre, Toronto, Canada
| | - Andrew J Bayley
- Radiation Medicine Program, Princess Margaret Cancer Centre, Toronto, Canada; Department of Radiation Oncology, University of Toronto, Canada
| | - Joanne Moseley
- Radiation Medicine Program, Princess Margaret Cancer Centre, Toronto, Canada
| | - Peter Chung
- Radiation Medicine Program, Princess Margaret Cancer Centre, Toronto, Canada; Department of Radiation Oncology, University of Toronto, Canada
| | - Charles Catton
- Radiation Medicine Program, Princess Margaret Cancer Centre, Toronto, Canada; Department of Radiation Oncology, University of Toronto, Canada
| | - Tim Craig
- Radiation Medicine Program, Princess Margaret Cancer Centre, Toronto, Canada; Department of Radiation Oncology, University of Toronto, Canada
| | - Michael Milosevic
- Radiation Medicine Program, Princess Margaret Cancer Centre, Toronto, Canada; Department of Radiation Oncology, University of Toronto, Canada
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12
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Nassef M, Simon A, Cazoulat G, Duménil A, Blay C, Lafond C, Acosta O, Balosso J, Haigron P, de Crevoisier R. Quantification of dose uncertainties in cumulated dose estimation compared to planned dose in prostate IMRT. Radiother Oncol 2016; 119:129-36. [DOI: 10.1016/j.radonc.2016.03.007] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2015] [Revised: 03/02/2016] [Accepted: 03/02/2016] [Indexed: 12/25/2022]
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13
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Kirby N, Chen J, Kim H, Morin O, Nie K, Pouliot J. An automated deformable image registration evaluation of confidence tool. Phys Med Biol 2016; 61:N203-14. [DOI: 10.1088/0031-9155/61/8/n203] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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14
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Scaife JE, Thomas SJ, Harrison K, Romanchikova M, Sutcliffe MPF, Forman JR, Bates AM, Jena R, Parker MA, Burnet NG. Accumulated dose to the rectum, measured using dose-volume histograms and dose-surface maps, is different from planned dose in all patients treated with radiotherapy for prostate cancer. Br J Radiol 2015. [PMID: 26204919 PMCID: PMC4730972 DOI: 10.1259/bjr.20150243] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
OBJECTIVE We sought to calculate accumulated dose (DA) to the rectum in patients treated with radiotherapy for prostate cancer. We were particularly interested in whether dose-surface maps (DSMs) provide additional information to dose-volume histograms (DVHs). METHODS Manual rectal contours were obtained for kilovoltage and daily megavoltage CT scans for 10 participants from the VoxTox study (380 scans). Daily delivered dose recalculation was performed using a ray-tracing algorithm. Delivered DVHs were summated to create accumulated DVHs. The rectum was considered as a cylinder, cut and unfolded to produce daily delivered DSMs; these were summated to produce accumulated DSMs. RESULTS Accumulated dose-volumes were different from planned in all participants. For one participant, all DA levels were higher and all volumes were larger than planned. For four participants, all DA levels were lower and all volumes were smaller than planned. For each of these four participants, ≥1% of pixels on the accumulated DSM received ≥5 Gy more than had been planned. CONCLUSION Differences between accumulated and planned dose-volumes were seen in all participants. DSMs were able to identify differences between DA and planned dose that could not be appreciated from the DVHs. Further work is needed to extract the dose data embedded in the DSMs. These will be correlated with toxicity as part of the VoxTox Programme. ADVANCES IN KNOWLEDGE DSMs are able to identify differences between DA and planned dose that cannot be appreciated from DVHs alone and should be incorporated into future studies investigating links between DA and toxicity.
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Affiliation(s)
- Jessica E Scaife
- 1 Cancer Research UK VoxTox Research Group, Department of Oncology, University of Cambridge, Addenbrooke's Hospital, Cambridge, UK.,2 Department of Oncology, University of Cambridge, Cambridge Biomedical Campus, Addenbrooke's Hospital, Cambridge, UK
| | - Simon J Thomas
- 1 Cancer Research UK VoxTox Research Group, Department of Oncology, University of Cambridge, Addenbrooke's Hospital, Cambridge, UK.,3 Medical Physics Department, Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK
| | - Karl Harrison
- 1 Cancer Research UK VoxTox Research Group, Department of Oncology, University of Cambridge, Addenbrooke's Hospital, Cambridge, UK.,4 Department of Physics, University of Cambridge, Cavendish Laboratory, Cambridge, UK
| | - Marina Romanchikova
- 1 Cancer Research UK VoxTox Research Group, Department of Oncology, University of Cambridge, Addenbrooke's Hospital, Cambridge, UK.,3 Medical Physics Department, Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK
| | - Michael P F Sutcliffe
- 1 Cancer Research UK VoxTox Research Group, Department of Oncology, University of Cambridge, Addenbrooke's Hospital, Cambridge, UK.,5 Department of Engineering, University of Cambridge, Cambridge, UK
| | - Julia R Forman
- 1 Cancer Research UK VoxTox Research Group, Department of Oncology, University of Cambridge, Addenbrooke's Hospital, Cambridge, UK.,6 Cambridge Clinical Trials Unit, Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK
| | - Amy M Bates
- 1 Cancer Research UK VoxTox Research Group, Department of Oncology, University of Cambridge, Addenbrooke's Hospital, Cambridge, UK.,2 Department of Oncology, University of Cambridge, Cambridge Biomedical Campus, Addenbrooke's Hospital, Cambridge, UK
| | - Raj Jena
- 1 Cancer Research UK VoxTox Research Group, Department of Oncology, University of Cambridge, Addenbrooke's Hospital, Cambridge, UK.,2 Department of Oncology, University of Cambridge, Cambridge Biomedical Campus, Addenbrooke's Hospital, Cambridge, UK
| | - M Andrew Parker
- 1 Cancer Research UK VoxTox Research Group, Department of Oncology, University of Cambridge, Addenbrooke's Hospital, Cambridge, UK.,4 Department of Physics, University of Cambridge, Cavendish Laboratory, Cambridge, UK
| | - Neil G Burnet
- 1 Cancer Research UK VoxTox Research Group, Department of Oncology, University of Cambridge, Addenbrooke's Hospital, Cambridge, UK.,2 Department of Oncology, University of Cambridge, Cambridge Biomedical Campus, Addenbrooke's Hospital, Cambridge, UK
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15
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Hayashi K, Isohashi F, Akino Y, Wakai N, Mabuchi S, Suzuki O, Seo Y, Ootani Y, Sumida I, Yoshioka Y, Kimura T, Ogawa K. Estimation of the total rectal dose of radical external beam and intracavitary radiotherapy for uterine cervical cancer using the deformable image registration method. JOURNAL OF RADIATION RESEARCH 2015; 56:546-52. [PMID: 25678538 PMCID: PMC4426921 DOI: 10.1093/jrr/rru127] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2014] [Revised: 12/15/2014] [Accepted: 12/25/2014] [Indexed: 05/25/2023]
Abstract
We adapted the deformable image registration (DIR) technique to accurately calculate the cumulative intracavitary brachytherapy (ICBT) and external beam radiotherapy (EBRT) rectal dose for treating uterine cervical cancer. A total of 14 patients with primary cervical cancer radically treated with ICRT and EBRT were analysed using the Velocity AI(TM) software. Computed tomography (CT) images were registered, and EBRT and ICBT dose distributions were determined. Cumulative D2cm (3), D1cm (3) and D0.1cm (3) were calculated by simple addition of fractional values or by DIR. The accuracy of DIR was evaluated by means of a virtual phantom mimicking the rectum. The dice similarity coefficient (DSC) was calculated to evaluate rectal contour concordance between CT images before and after DIR. Virtual phantom analysis revealed that the average difference between the DIR-based phantom Dmean and the simple phantom Dmean was 1.9 ± 2.5 Gy (EQD2), and the DIR method included an uncertainty of ∼8.0%. The mean DSC between reference CT and CT was significantly improved after DIR (EBRT: 0.43 vs 0.85, P < 0.005; ICBT: 0.60 vs 0.87, P < 0.005). The average simple rectal D2cm (3), D1cm (3) and D0.1cm (3) values were 77.6, 81.6 and 91.1 Gy (EQD2), respectively; the DIR-based values were 76.2, 79.5 and 87.6 Gy, respectively. The simple addition values were overestimated, on average, by 3.1, 3.7 and 5.5 Gy, respectively, relative to the DIR-based values. In conclusion, the difference between the simple rectal dose-volume histogram (DVH) parameter addition and DIR-based cumulative rectal doses increased with decreasing DVH parameters.
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Affiliation(s)
- Kazuhiko Hayashi
- Department of Radiation Oncology, Osaka University Graduate School of Medicine, Osaka, Japan
| | - Fumiaki Isohashi
- Department of Radiation Oncology, Osaka University Graduate School of Medicine, Osaka, Japan
| | - Yuichi Akino
- Department of Radiology, Suita Tokushukai Hospital, Osaka, Japan
| | - Nobuhide Wakai
- Department of Radiation Oncology, Nara Medical University, Nara, Japan
| | - Seiji Mabuchi
- Department of Obstetrics and Gynecology, Osaka University Graduate School of Medicine, Osaka, Japan
| | - Osamu Suzuki
- Department of Radiation Oncology, Osaka University Graduate School of Medicine, Osaka, Japan
| | - Yuji Seo
- Department of Radiation Oncology, Osaka University Graduate School of Medicine, Osaka, Japan
| | - Yuki Ootani
- Department of Radiation Oncology, Osaka University Graduate School of Medicine, Osaka, Japan
| | - Iori Sumida
- Department of Radiation Oncology, Osaka University Graduate School of Medicine, Osaka, Japan
| | - Yasuo Yoshioka
- Department of Radiation Oncology, Osaka University Graduate School of Medicine, Osaka, Japan
| | - Tadashi Kimura
- Department of Obstetrics and Gynecology, Osaka University Graduate School of Medicine, Osaka, Japan
| | - Kazuhiko Ogawa
- Department of Radiation Oncology, Osaka University Graduate School of Medicine, Osaka, Japan
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16
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Assessment of cumulative external beam and intracavitary brachytherapy organ doses in gynecologic cancers using deformable dose summation. Radiother Oncol 2015; 115:195-202. [DOI: 10.1016/j.radonc.2015.04.002] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2013] [Revised: 03/26/2015] [Accepted: 04/05/2015] [Indexed: 11/23/2022]
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17
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Abe T, Tamaki T, Makino S, Ebara T, Hirai R, Miyaura K, Kumazaki Y, Ohno T, Shikama N, Nakano T, Kato S. Assessing cumulative dose distributions in combined radiotherapy for cervical cancer using deformable image registration with pre-imaging preparations. Radiat Oncol 2014; 9:293. [PMID: 25526986 PMCID: PMC4296553 DOI: 10.1186/s13014-014-0293-4] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2014] [Accepted: 12/08/2014] [Indexed: 11/20/2022] Open
Abstract
Background The purpose of the study was to evaluate the feasibility of deformable image registration (DIR) in assessing cumulative dose distributions of the combination of external beam radiotherapy (EBRT) and fractionated intracavitary brachytherapy (ICBT) for cervical cancer. Materials and methods Three-dimensional image data sets of five consecutive patients were used. The treatment plan consisted of whole pelvic EBRT (total dose: 45 Gy in 25 fractions) combined with computed tomography (CT)-based high-dose rate ICBT (≥24 Gy in 4 fractions to the high risk clinical target volume (HR-CTV)). Organs at risk and HR-CTV were contoured on each CT images and dose-volume parameters were acquired. Pre-imaging preparations were performed prior to each ICBT to minimize the uncertainty of the organ position. Physical doses of each treatment were converted to biologically equivalent doses in 2 Gy daily fractions by the linear quadratic model. Three-dimensional dose distributions of each treatment were accumulated on CT images of the first ICBT using DIR with commercially available image registration software (MIM Maestro®). To compare with DIR, 3D dose distributions were fused by rigid registration based on bony structure matching. To evaluate the accuracy of DIR, the Dice similarity coefficient (DSC) was measured between deformed contours and initial contours. Results The cumulative dose distributions were successfully illustrated on the CT images using DIR. Mean DSCs of the HR-CTV, rectum, and bladder were 0.46, 0.62 and 0.69, respectively, with rigid registration; and 0.78, 0.76, and 0.87, respectively, with DIR (p <0.05). The mean DSCs derived from our DIR procedure were comparable to those of previous reports describing the quality of DIR algorithms in the pelvic region. DVH parameters derived from the 2 methods showed no significant difference. Conclusions Our results suggest that DIR-based dose accumulation may be acceptable for assessing cumulative dose distributions to assess doses to the tumor and organs at risk in combined radiotherapy for cervical cancer under pre-imaging preparations.
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Affiliation(s)
- Takanori Abe
- Department of Radiation Oncology, Saitama Medical University, International Medical Center, 1397-1 Yamane, Hidaka-shi, 350-1298, Japan.
| | - Tomoaki Tamaki
- Department of Radiation Oncology, Saitama Medical University, International Medical Center, 1397-1 Yamane, Hidaka-shi, 350-1298, Japan.
| | - Souichi Makino
- Department of Radiation Oncology, Saitama Medical University, International Medical Center, 1397-1 Yamane, Hidaka-shi, 350-1298, Japan.
| | - Takeshi Ebara
- Gunma Prefectural Cancer Center, 617-1 Takabayashinishi-machi, Ohta-shi, Gunma, 373-8550, Japan.
| | - Ryuuta Hirai
- Department of Radiation Oncology, Saitama Medical University, International Medical Center, 1397-1 Yamane, Hidaka-shi, 350-1298, Japan.
| | - Kazunori Miyaura
- Department of Radiation Oncology, Saitama Medical University, International Medical Center, 1397-1 Yamane, Hidaka-shi, 350-1298, Japan.
| | - Yu Kumazaki
- Department of Radiation Oncology, Saitama Medical University, International Medical Center, 1397-1 Yamane, Hidaka-shi, 350-1298, Japan.
| | - Tatsuya Ohno
- Gunma University Heavy Ion Medical Center, 3-39-22 Showa-machi, Maebashi-shi, Gunma, 371-8511, Japan.
| | - Naoto Shikama
- Department of Radiation Oncology, Saitama Medical University, International Medical Center, 1397-1 Yamane, Hidaka-shi, 350-1298, Japan.
| | - Takashi Nakano
- Department of Radiation Oncology, Gunma University, 3-39-22 Showa-machi, Maebashi-shi, Gunma, 371-8511, Japan.
| | - Shingo Kato
- Department of Radiation Oncology, Saitama Medical University, International Medical Center, 1397-1 Yamane, Hidaka-shi, 350-1298, Japan.
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