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Hasler SW, Kallehauge JF, Hansen RH, Samsøe E, Arp DT, Nissen HD, Edmund JM, Bernchou U, Mahmood F. Geometric distortions in clinical MRI sequences for radiotherapy: insights gained from a multicenter investigation. Acta Oncol 2023; 62:1551-1560. [PMID: 37815867 DOI: 10.1080/0284186x.2023.2266560] [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: 05/23/2023] [Accepted: 09/28/2023] [Indexed: 10/12/2023]
Abstract
BACKGROUND As magnetic resonance imaging (MRI) becomes increasingly integrated into radiotherapy (RT) for enhanced treatment planning and adaptation, the inherent geometric distortion in acquired MR images pose a potential challenge to treatment accuracy. This study aimed to evaluate the geometric distortion levels in the clinical MRI protocols used across Danish RT centers and discuss influence of specific sequence parameters. Based on the variety in geometric performance across centers, we assess if harmonization of MRI sequences is a relevant measure. MATERIALS AND METHODS Nine centers participated with 12 MRI scanners and MRI-Linacs (MRL). Using a travelling phantom approach, a reference MRI sequence was used to assess variation in baseline distortion level between scanners. The phantom was also scanned with local clinical MRI sequences for brain, head/neck (H/N), abdomen, and pelvis. The influence of echo time, receiver bandwidth, image weighting, and 2D/3D acquisition was investigated. RESULTS We found a large variation in geometric accuracy across 93 clinical sequences examined, exceeding the baseline variation found between MRI scanners (σ = 0.22 mm), except for abdominal sequences where the variation was lower. Brain and abdominal sequences showed lowest distortion levels ([0.22, 2.26] mm), and a large variation in performance was found for H/N and pelvic sequences ([0.19, 4.07] mm). Post hoc analyses revealed that distortion levels decreased with increasing bandwidth and a less clear increase in distortion levels with increasing echo time. 3D MRI sequences had lower distortion levels than 2D (median of 1.10 and 2.10 mm, respectively), and in DWI sequences, the echo-planar imaging read-out resulted in highest distortion levels. CONCLUSION There is a large variation in the geometric distortion levels of clinical MRI sequences across Danish RT centers, and between anatomical sites. The large variation observed makes harmonization of MRI sequences across institutions and adoption of practices from well-performing anatomical sites, a relevant measure within RT.
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Affiliation(s)
- Signe Winther Hasler
- Laboratory of Radiation Physics, Department of Oncology, Odense University Hospital, Odense, Denmark
- Department of Clinical Research, University of Southern Denmark, Odense, Denmark
| | - Jesper Folsted Kallehauge
- Danish Centre for Particle Therapy, Aarhus University Hospital, Aarhus, Denmark
- Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Rasmus Hvass Hansen
- Section for Radiation Therapy, Department of Oncology, Center for Cancer and Organ Diseases, Copenhagen University Hospital, Copenhagen, Denmark
| | - Eva Samsøe
- Department of Clinical Oncology, Zealand University Hospital, Naestved, Denmark
| | - Dennis Tideman Arp
- Department of Medical Physics, Department of Oncology, Aalborg University Hospital, Aalborg, Denmark
| | - Henrik Dahl Nissen
- Department of Medical Physics, Vejle Hospital, University Hospital of Southern Denmark, Vejle, Denmark
| | - Jens M Edmund
- Radiotherapy Research Unit, Department of Oncology, Herlev and Gentofte Hospital, Herlev, Denmark
- Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark
| | - Uffe Bernchou
- Laboratory of Radiation Physics, Department of Oncology, Odense University Hospital, Odense, Denmark
- Department of Clinical Research, University of Southern Denmark, Odense, Denmark
| | - Faisal Mahmood
- Laboratory of Radiation Physics, Department of Oncology, Odense University Hospital, Odense, Denmark
- Department of Clinical Research, University of Southern Denmark, Odense, Denmark
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2
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Koivula L, Seppälä T, Collan J, Visapää H, Tenhunen M, Korhonen A. Synthetic computed tomography based dose calculation in prostate cancer patients with hip prostheses for magnetic resonance imaging-only radiotherapy. Phys Imaging Radiat Oncol 2023; 27:100469. [PMID: 37520639 PMCID: PMC10371839 DOI: 10.1016/j.phro.2023.100469] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2023] [Revised: 07/05/2023] [Accepted: 07/06/2023] [Indexed: 08/01/2023] Open
Abstract
Background and purpose Metallic hip prostheses cause substantial artefacts in both computed tomography (CT) and magnetic resonance (MR) images used in radiotherapy treatment planning (RTP) for prostate cancer patients. The aim of this study was to evaluate the dose calculation accuracy of a synthetic CT (sCT) generation workflow and the improvement in implant visibility using metal artefact reduction sequences. Materials and methods The study included 23 patients with prostate cancer who had hip prostheses, of which 10 patients had bilateral hip implants. An in-house protocol was applied to create sCT images for dose calculation comparison. The study compared prostheses volumes and resulting avoidance sectors against planning target volume (PTV) dose uniformity and organs at risk (OAR) sparing. Results Median PTV dose difference between sCT and CT-based dose calculation among all patients was 0.1 % (-0.4 to 0.4%) (median(range)). Bladder and rectum differences (V50Gy) were 0.2 % (-0.3 to 1.1%) and 0.1 % (-0.9 to 0.5%). The median 3D local gamma pass rate for partial arc cases using a Dixon MR sequence was Γ20%2mm/2% = 99.9%. For the bilateral full arc cases, using a metal artefact reconstruction sequence, the pass rate was Γ20%2mm/2% = 99.0%. Conclusions An in-house protocol for generating sCT images for dose calculation provided clinically feasible dose calculation accuracy for prostate cancer patients with hip implants. PTV median dose difference for uni- and bilateral patients with avoidance sectors remained <0.4%. The Outphase images enhanced implant visibility resulting in smaller avoidance sectors, better OAR sparing, and improved PTV uniformity.
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Affiliation(s)
- Lauri Koivula
- Department of Physics, MATRENA-doctoral programme, University of Helsinki, Gustaf Hällströmin katu 2, 00560 Helsinki, Finland
- Comprehensive Cancer Center, Helsinki University Hospital and University of Helsinki, Haartmaninkatu 4 Building 2, 00290 Helsinki, Finland
| | - Tiina Seppälä
- Comprehensive Cancer Center, Helsinki University Hospital and University of Helsinki, Haartmaninkatu 4 Building 2, 00290 Helsinki, Finland
| | - Juhani Collan
- Comprehensive Cancer Center, Helsinki University Hospital and University of Helsinki, Haartmaninkatu 4 Building 2, 00290 Helsinki, Finland
| | - Harri Visapää
- Comprehensive Cancer Center, Helsinki University Hospital and University of Helsinki, Haartmaninkatu 4 Building 2, 00290 Helsinki, Finland
| | - Mikko Tenhunen
- Comprehensive Cancer Center, Helsinki University Hospital and University of Helsinki, Haartmaninkatu 4 Building 2, 00290 Helsinki, Finland
| | - Arthur Korhonen
- Department of Medical Physics, Kymenlaakso Central Hospital, Kymenlaakso Social and Health Services (KymenHVA), Kotkantie 41, 48210 Kotka, Finland
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Zhang X, Liu T, Zhang H, Zhang M. Measurements of target volumes and organs at risk using DW‑MRI in patients with central lung cancer accompanied with atelectasis. Mol Clin Oncol 2023; 18:45. [PMID: 37152713 PMCID: PMC10155240 DOI: 10.3892/mco.2023.2641] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Accepted: 03/29/2023] [Indexed: 05/09/2023] Open
Abstract
Accurate imaging-based tumor delineation is crucial for guiding the radiotherapy treatments of various solid tumors. Currently, several imaging procedures, including diffusion-weighted magnetic resonance imaging (DW-MRI), intensified computed tomography and positron emission tomography are routinely used for targeted tumor delineation. However, the performance of these imaging procedures has not yet been comprehensively evaluated. In order to address this matter, the present study was conducted in an aim to assess the use of DW-MRI in guiding radiotherapy treatments, by comparing its performance to that of other imaging procedures. Specifically, the exposure dosages to organs at risk, including the lungs, heart and spinal mencord, were evaluated using various radiotherapy regimes. The findings of the present study demonstrated that DW-MRI is a non-invasive and cost-effective imaging procedure that can be used to reduce lung exposure doses, minimizing the risk of radiation pneumonitis. The data further demonstrate the immense potential of the DW-MRI procedure in the precision radiotherapy of lung cancers.
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Affiliation(s)
- Xinli Zhang
- Department of Medical Oncology, The Affiliated Tai'an City Central Hospital of Qingdao University, Tai'an, Shandong 271000, P.R. China
- Department of Radiation Oncology, Shandong Cancer Hospital and Institute, Shandong University, Jinan, Shandong 250117, P.R. China
| | - Tong Liu
- Department of Stomatology, The Affiliated Tai'an City Central Hospital of Qingdao University, Tai'an, Shandong 271000, P.R. China
| | - Hong Zhang
- Department of Medical Oncology, The Affiliated Tai'an City Central Hospital of Qingdao University, Tai'an, Shandong 271000, P.R. China
| | - Mingbin Zhang
- Department of Stomatology, The Affiliated Tai'an City Central Hospital of Qingdao University, Tai'an, Shandong 271000, P.R. China
- Correspondence to: Dr Mingbin Zhang, Department of Stomatology, The Affiliated Tai'an City Central Hospital of Qingdao University, 29 Longtan Road, Tai'an, Shandong 271000, P.R. China
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Vanhanen A, Reinikainen P, Kapanen M. Radiation-induced prostate swelling during SBRT of the prostate. Acta Oncol 2022; 61:698-704. [PMID: 35435111 DOI: 10.1080/0284186x.2022.2062682] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
Abstract
BACKGROUND Reduced planning target volume (PTV) margins are commonly used in stereotactic body radiotherapy (SBRT) of the prostate. In addition, MR-only treatment planning is becoming more common in prostate radiotherapy and compared to CT-MRI-based contouring results in notable smaller clinical target volume (CTV). Tight PTV margins coupled with MR-only planning raise a concern whether the margins are adequate enough to cover possible volumetric changes of the prostate. The aim of this study was to evaluate the volumetric change of the prostate and its effect on PTV margin during 5x7.25 Gy SBRT of the prostate. MATERIAL AND METHODS Twenty patients were included in the study. Three MRI scans, first prior to treatment (baseline), second after third fraction (mid-treatment) and third after fifth fraction (end-treatment) were acquired for each patient. Prostate contours were delineated on each MRI scan and used to assess the prostate volume and maximum prostate diameter on left-right (LR), anterior-posterior (AP) and superior-inferior (SI) directions at baseline, mid- and end-treatment. RESULTS Median (IQR) change in the prostate volume relative to the baseline was 12.0% (3.1, 17.7) and 9.2% (2.0, 18.9) at the mid- and end-treatment, respectively, and the change was statistically significant (p = 0.004 and p = 0.020, respectively). Compared to the baseline, median increase in the maximum LR, SI and AP prostate diameters were 0.8, 2.3 and 1.5 mm at mid-treatment, and 0.5, 2.5 and 2.3 mm at end-treatment, respectively. CONCLUSION If prostate contouring is based solely on MRI (e.g., in MR-only protocol), additional margin of 1-2 mm should be considered to account for prostate swelling. The study is part of clinical trial NCT02319239.
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Affiliation(s)
- Antti Vanhanen
- Department of Oncology, Unit of Radiotherapy, Tampere University Hospital, Tampere, Finland
- Department of Medical Physics, Medical Imaging Center, Tampere University Hospital, Tampere, Finland
| | - Petri Reinikainen
- Department of Oncology, Unit of Radiotherapy, Tampere University Hospital, Tampere, Finland
| | - Mika Kapanen
- Department of Medical Physics, Medical Imaging Center, Tampere University Hospital, Tampere, Finland
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5
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Omidi A, Weiss E, Wilson JS, Rosu-Bubulac M. Quantitative assessment of intra- and inter-modality deformable image registration of the heart, left ventricle, and thoracic aorta on longitudinal 4D-CT and MR images. J Appl Clin Med Phys 2021; 23:e13500. [PMID: 34962065 PMCID: PMC8833287 DOI: 10.1002/acm2.13500] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Revised: 09/17/2021] [Accepted: 11/29/2021] [Indexed: 12/25/2022] Open
Abstract
Purpose Magnetic resonance imaging (MRI)‐based investigations into radiotherapy (RT)‐induced cardiotoxicity require reliable registrations of magnetic resonance (MR) imaging to planning computed tomography (CT) for correlation to regional dose. In this study, the accuracy of intra‐ and inter‐modality deformable image registration (DIR) of longitudinal four‐dimensional CT (4D‐CT) and MR images were evaluated for heart, left ventricle (LV), and thoracic aorta (TA). Methods and materials Non‐cardiac‐gated 4D‐CT and T1 volumetric interpolated breath‐hold examination (T1‐VIBE) MRI datasets from five lung cancer patients were obtained at two breathing phases (inspiration/expiration) and two time points (before treatment and 5 weeks after initiating RT). Heart, LV, and TA were manually contoured. Each organ underwent three intramodal DIRs ((A) CT modality over time, (B) MR modality over time, and (C) MR contrast effect at the same time) and two intermodal DIRs ((D) CT/MR multimodality at same time and (E) CT/MR multimodality over time). Hausdorff distance (HD), mean distance to agreement (MDA), and Dice were evaluated and assessed for compliance with American Association of Physicists in Medicine (AAPM) Task Group (TG)‐132 recommendations. Results Mean values of HD, MDA, and Dice under all registration scenarios for each region of interest ranged between 8.7 and 16.8 mm, 1.0 and 2.6 mm, and 0.85 and 0.95, respectively, and were within the TG‐132 recommended range (MDA < 3 mm, Dice > 0.8). Intramodal DIR showed slightly better results compared to intermodal DIR. Heart and TA demonstrated higher registration accuracy compared to LV for all scenarios except for HD and Dice values in Group A. Significant differences for each metric and tissue of interest were noted between Groups B and D and between Groups B and E. MDA and Dice significantly differed between LV and heart in all registrations except for MDA in Group E. Conclusions DIR of the heart, LV, and TA between non‐cardiac‐gated longitudinal 4D‐CT and MRI across two modalities, breathing phases, and pre/post‐contrast is acceptably accurate per AAPM TG‐132 guidelines. This study paves the way for future evaluation of RT‐induced cardiotoxicity and its related factors using multimodality DIR.
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Affiliation(s)
- Alireza Omidi
- Department of Biomedical Engineering, College of Engineering, Virginia Commonwealth University, Richmond, Virginia, USA
| | - Elisabeth Weiss
- Department of Radiation Oncology, Virginia Commonwealth University Health, Richmond, Virginia, USA
| | - John S Wilson
- Department of Biomedical Engineering, College of Engineering, Virginia Commonwealth University, Richmond, Virginia, USA.,Pauley Heart Center, Virginia Commonwealth University Health System, Richmond, Virginia, USA
| | - Mihaela Rosu-Bubulac
- Department of Radiation Oncology, Virginia Commonwealth University Health, Richmond, Virginia, USA
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Persson E, Emin S, Scherman J, Jamtheim Gustafsson C, Brynolfsson P, Ceberg S, Gunnlaugsson A, Olsson LE. Investigation of the clinical inter-observer bias in prostate fiducial marker image registration between CT and MR images. Radiat Oncol 2021; 16:150. [PMID: 34399806 PMCID: PMC8365967 DOI: 10.1186/s13014-021-01865-8] [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: 01/12/2021] [Accepted: 07/17/2021] [Indexed: 01/17/2023] Open
Abstract
Background and purpose Inter-modality image registration between computed tomography (CT) and magnetic resonance (MR) images is associated with systematic uncertainties and the magnitude of these uncertainties is not well documented.
The purpose of this study was to investigate the potential uncertainty of gold fiducial marker (GFM) registration for localized prostate cancer and to estimate the inter-observer bias in a clinical setting. Methods
Four experienced observers registered CT and MR images for 42 prostate cancer patients. Manual GFM identification was followed by a landmark-based registration. The absolute difference between observers in GFM identification and the displacement of the clinical target volume (CTV) was investigated. The CTV center of mass (CoM) vector displacements, DICE-index and Hausdorff distances for the observer registrations were compared against a clinical baseline registration. The time allocated for the manual registrations was compared. Results Absolute difference in GFM identification between observers ranged from 0.0 to 3.0 mm. The maximum CTV CoM displacement from the clinical baseline was 3.1 mm. Displacements larger than or equal to 1 mm, 2 mm and 3 mm were 46%, 18% and 4%, respectively. No statistically significant difference was detected between observers in terms of CTV displacement. Median DICE-index and Hausdorff distance for the CTV, with their respective ranges were 0.94 [0.70–1.00] and 2.5 mm [0.7–8.7]. Conclusions Registration of CT and MR images using GFMs for localized prostate cancer patients was subject to inter-observer bias on an individual patient level. A CTV displacement as large as 3 mm occurred for individual patients. These results show that GFM registration in a clinical setting is associated with uncertainties, which motivates the removal of inter-modality registrations in the radiotherapy workflow and a transition to an MRI-only workflow for localized prostate cancer.
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Affiliation(s)
- Emilia Persson
- Radiation Physics, Department of Hematology, Oncology, and Radiation Physics , Skåne University Hospital, Klinikgatan 5, 221 85, Lund, Sweden. .,Department of Translational Medicine, Medical Radiation Physics, Lund University, Carl Bertil Laurellsgata 9, 205 02, Malmö, Sweden.
| | - Sevgi Emin
- Radiation Physics, Department of Hematology, Oncology, and Radiation Physics , Skåne University Hospital, Klinikgatan 5, 221 85, Lund, Sweden
| | - Jonas Scherman
- Radiation Physics, Department of Hematology, Oncology, and Radiation Physics , Skåne University Hospital, Klinikgatan 5, 221 85, Lund, Sweden
| | - Christian Jamtheim Gustafsson
- Radiation Physics, Department of Hematology, Oncology, and Radiation Physics , Skåne University Hospital, Klinikgatan 5, 221 85, Lund, Sweden.,Department of Translational Medicine, Medical Radiation Physics, Lund University, Carl Bertil Laurellsgata 9, 205 02, Malmö, Sweden
| | - Patrik Brynolfsson
- Department of Translational Medicine, Medical Radiation Physics, Lund University, Carl Bertil Laurellsgata 9, 205 02, Malmö, Sweden
| | - Sofie Ceberg
- Department of Medical Radiation Physics, Lund University, Barngatan 4, 222 85, Lund, Sweden
| | - Adalsteinn Gunnlaugsson
- Radiation Physics, Department of Hematology, Oncology, and Radiation Physics , Skåne University Hospital, Klinikgatan 5, 221 85, Lund, Sweden
| | - Lars E Olsson
- Radiation Physics, Department of Hematology, Oncology, and Radiation Physics , Skåne University Hospital, Klinikgatan 5, 221 85, Lund, Sweden.,Department of Translational Medicine, Medical Radiation Physics, Lund University, Carl Bertil Laurellsgata 9, 205 02, Malmö, Sweden
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Yoo D, Choi YA, Rah CJ, Lee E, Cai J, Min BJ, Kim EH. Signal Enhancement of Low Magnetic Field Magnetic Resonance Image Using a Conventional- and Cyclic-Generative Adversarial Network Models With Unpaired Image Sets. Front Oncol 2021; 11:660284. [PMID: 34046353 PMCID: PMC8144640 DOI: 10.3389/fonc.2021.660284] [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: 01/29/2021] [Accepted: 04/08/2021] [Indexed: 11/23/2022] Open
Abstract
In this study, the signal enhancement ratio of low-field magnetic resonance (MR) images was investigated using a deep learning-based algorithm. Unpaired image sets (0.06 Tesla and 1.5 Tesla MR images for different patients) were used in this study following three steps workflow. In the first step, the deformable registration of a 1.5 Tesla MR image into a 0.06 Tesla MR image was performed to ensure that the shapes of the unpaired set matched. In the second step, a cyclic-generative adversarial network (GAN) was used to generate a synthetic MR image of the original 0.06 Tesla MR image based on the deformed or original 1.5 Tesla MR image. Finally, an enhanced 0.06 Tesla MR image could be generated using the conventional-GAN with the deformed or synthetic MR image. The results from the optimized flow and enhanced MR images showed significant signal enhancement of the anatomical view, especially in the nasal septum, inferior nasal choncha, nasopharyngeal fossa, and eye lens. The signal enhancement ratio, signal-to-noise ratio (SNR) and correlation factor between the original and enhanced MR images were analyzed for the evaluation of the image quality. A combined method using conventional- and cyclic-GANs is a promising approach for generating enhanced MR images from low-magnetic-field MR.
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Affiliation(s)
- Denis Yoo
- Artificial Intelligence Research Lab, Talos, Sheung Wan, Hong Kong
| | | | - C J Rah
- Artificial Intelligence Research Lab, Talos, Sheung Wan, Hong Kong
| | - Eric Lee
- Artificial Intelligence Research Lab, Talos, Sheung Wan, Hong Kong
| | - Jing Cai
- Department of Health Technology & Informatics, Hong Kong Polytechnic University, Hung Hom, Hong Kong
| | - Byung Jun Min
- Department of Radiation Oncology, Chungbuk National University Hospital, Cheongju, South Korea
| | - Eun Ho Kim
- Department of Biochemistry, School of Medicine, Daegu Catholic University, Daegu, South Korea
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8
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Bernstein D, Taylor A, Nill S, Imseeh G, Kothari G, Llewelyn M, De Paepe KN, Rockall A, Shiarli AM, Oelfke U. An Inter-observer Study to Determine Radiotherapy Planning Target Volumes for Recurrent Gynaecological Cancer Comparing Magnetic Resonance Imaging Only With Computed Tomography-Magnetic Resonance Imaging. Clin Oncol (R Coll Radiol) 2021; 33:307-313. [PMID: 33640196 PMCID: PMC8051139 DOI: 10.1016/j.clon.2021.02.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Revised: 01/11/2021] [Accepted: 02/05/2021] [Indexed: 11/25/2022]
Abstract
AIMS Target delineation uncertainty is arguably the largest source of geometric uncertainty in radiotherapy. Several factors can affect it, including the imaging modality used for delineation. It is accounted for by applying safety margins to the target to produce a planning target volume (PTV), to which treatments are designed. To determine the margin, the delineation uncertainty is measured as the delineation error, and then a margin recipe used. However, there is no published evidence of such analysis for recurrent gynaecological cancers (RGC). The aims of this study were first to quantify the delineation uncertainty for RGC gross tumour volumes (GTVs) and to calculate the associated PTV margins and then to quantify the difference in GTV, delineation uncertainty and PTV margin, between a computed tomography-magnetic resonance imaging (CT-MRI) and MRI workflow. MATERIALS AND METHODS Seven clinicians delineated the GTV for 20 RGC tumours on co-registered CT and MRI datasets (CT-MRI) and on MRI alone. The delineation error, the standard deviation of distances from each clinician's outline to a reference, was measured and the required PTV margin determined. Differences between using CT-MRI and MRI alone were assessed. RESULTS The overall delineation error and the resulting margin were 3.1 mm and 8.5 mm, respectively, for CT-MRI, reducing to 2.5 mm and 7.1 mm, respectively, for MRI alone. Delineation errors and therefore the theoretical margins, varied widely between patients. MRI tumour volumes were on average 15% smaller than CT-MRI tumour volumes. DISCUSSION This study is the first to quantify delineation error for RGC tumours and to calculate the corresponding PTV margin. The determined margins were larger than those reported in the literature for similar patients, bringing into question both current margins and margin calculation methods. The wide variation in delineation error between these patients suggests that applying a single population-based margin may result in PTVs that are suboptimal for many. Finally, the reduced tumour volumes and safety margins suggest that patients with RGC may benefit from an MRI-only treatment workflow.
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Affiliation(s)
- D Bernstein
- Joint Department of Physics, The Institute of Cancer Research and The Royal Marsden NHS Foundation Trust, London, UK.
| | - A Taylor
- Gynaecology Unit, Royal Marsden NHS Foundation Trust, London, UK
| | - S Nill
- Joint Department of Physics, The Institute of Cancer Research and The Royal Marsden NHS Foundation Trust, Sutton, London, UK
| | - G Imseeh
- Gynaecology Unit, Royal Marsden NHS Foundation Trust, London, UK; Radiotherapy and Imaging, The Institute of Cancer Research and The Royal Marsden NHS Foundation Trust, Sutton, London, UK
| | - G Kothari
- Gynaecology Unit, Royal Marsden NHS Foundation Trust, London, UK; Peter MacCallum Cancer Center, Melbourne, Victoria, Australia
| | - M Llewelyn
- Gynaecology Unit, Royal Marsden NHS Foundation Trust, London, UK
| | - K N De Paepe
- Radiotherapy and Imaging, The Institute of Cancer Research and The Royal Marsden NHS Foundation Trust, Sutton, London, UK; Department of Radiology, Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK
| | - A Rockall
- Department of Radiology, Royal Marsden NHS Foundation Trust, London, UK; Department of Surgery and Cancer, Imperial College London, London, UK
| | - A-M Shiarli
- Gynaecology Unit, Royal Marsden NHS Foundation Trust, London, UK
| | - U Oelfke
- Joint Department of Physics, The Institute of Cancer Research and The Royal Marsden NHS Foundation Trust, Sutton, London, UK
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9
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Kavaluus H, Nousiainen K, Kaijaluoto S, Seppälä T, Saarilahti K, Tenhunen M. Determination of acceptance criteria for geometric accuracy of magnetic resonance imaging scanners used in radiotherapy planning. PHYSICS & IMAGING IN RADIATION ONCOLOGY 2021; 17:58-64. [PMID: 33898780 PMCID: PMC8058029 DOI: 10.1016/j.phro.2021.01.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Revised: 01/14/2021] [Accepted: 01/14/2021] [Indexed: 12/23/2022]
Abstract
Geometric accuracy of MRI-scanners in radiotherapy planning must be evaluated. Phantom acquisitions with standard and clinical sequences were performed. Geometric distortions were determined in several volumes of interest. We recommend acceptance criteria for MRI-scanners in radiotherapy planning. Explicit and simple acceptance criteria enable effective regulatory inspections.
Background and Purpose Magnetic resonance imaging is increasingly used in radiotherapy planning; yet, the performance of the utilized scanners is rarely regulated by any authority. The aim of this study was to determine the geometric accuracy of several magnetic resonance imaging scanners used for radiotherapy planning, and to establish acceptance criteria for such scanners. Materials and Methods The geometric accuracy of five different scanners was measured with three sequences using a commercial large-field-of-view phantom. The distortion magnitudes were determined in spherical volumes around the scanner isocenter and in cylindrical volumes along scanner z-axis. The repeatability of the measurements was determined on a single scanner with two quality assurance sequences with three single-setup and seven repeated-setup measurements. Results For all scanners and sequences except one, the mean and median distortion magnitude was <1 mm and <2 mm in spherical volumes with diameters of 400 mm and 500 mm, respectively. For all sequences maximum distortion was <2 mm in spherical volume with diameter of 300 mm. The mean standard deviation of marker-by-marker distortion magnitudes over repeated acquisitions was ≤0.6 mm with both tested sequences. Conclusions All tested scanners were geometrically accurate for their current use in radiotherapy planning. The acceptance criteria of geometric accuracy for regulatory inspections of a supervising authority could be set according to these results.
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Affiliation(s)
- Henna Kavaluus
- Radiation and Nuclear Safety Authority, STUK, Laippatie 4, FI-00880 Helsinki, Finland.,HUS Cancer Center, Helsinki University Hospital and University of Helsinki, P.O. Box 180, FI-00029 Helsinki, Finland.,Department of Physics, University of Helsinki, P.O. Box 64, FI-00014 Helsinki, Finland
| | - Katri Nousiainen
- Radiation and Nuclear Safety Authority, STUK, Laippatie 4, FI-00880 Helsinki, Finland.,HUS Cancer Center, Helsinki University Hospital and University of Helsinki, P.O. Box 180, FI-00029 Helsinki, Finland.,Department of Physics, University of Helsinki, P.O. Box 64, FI-00014 Helsinki, Finland.,HUS Medical Imaging Center, Helsinki University Hospital and University of Helsinki, B.O. Box 340, FI-00029 Helsinki, Finland
| | - Sampsa Kaijaluoto
- Radiation and Nuclear Safety Authority, STUK, Laippatie 4, FI-00880 Helsinki, Finland
| | - Tiina Seppälä
- HUS Cancer Center, Helsinki University Hospital and University of Helsinki, P.O. Box 180, FI-00029 Helsinki, Finland
| | - Kauko Saarilahti
- HUS Cancer Center, Helsinki University Hospital and University of Helsinki, P.O. Box 180, FI-00029 Helsinki, Finland
| | - Mikko Tenhunen
- HUS Cancer Center, Helsinki University Hospital and University of Helsinki, P.O. Box 180, FI-00029 Helsinki, Finland
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10
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Rigaud B, Simon A, Castelli J, Lafond C, Acosta O, Haigron P, Cazoulat G, de Crevoisier R. Deformable image registration for radiation therapy: principle, methods, applications and evaluation. Acta Oncol 2019; 58:1225-1237. [PMID: 31155990 DOI: 10.1080/0284186x.2019.1620331] [Citation(s) in RCA: 64] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Background: Deformable image registration (DIR) is increasingly used in the field of radiation therapy (RT) to account for anatomical deformations. The aims of this paper are to describe the main applications of DIR in RT and discuss current DIR evaluation methods. Methods: Articles on DIR published from January 2000 to October 2018 were extracted from PubMed and Science Direct. Our search was restricted to articles that report data obtained from humans, were written in English, and address DIR methods for RT. A total of 207 articles were selected from among 2506 identified in the search process. Results: At planning, DIR is used for organ delineation using atlas-based segmentation, deformation-based planning target volume definition, functional planning and magnetic resonance imaging-based dose calculation. In image-guided RT, DIR is used for contour propagation and dose calculation on per-treatment imaging. DIR is also used to determine the accumulated dose from fraction to fraction in external beam RT and brachytherapy, both for dose reporting and adaptive RT. In the case of re-irradiation, DIR can be used to estimate the cumulated dose of the two irradiations. Finally, DIR can be used to predict toxicity in voxel-wise population analysis. However, the evaluation of DIR remains an open issue, especially when dealing with complex cases such as the disappearance of matter. To quantify DIR uncertainties, most evaluation methods are limited to geometry-based metrics. Software companies have now integrated DIR tools into treatment planning systems for clinical use, such as contour propagation and fraction dose accumulation. Conclusions: DIR is increasingly important in RT applications, from planning to toxicity prediction. DIR is routinely used to reduce the workload of contour propagation. However, its use for complex dosimetric applications must be carefully evaluated by combining quantitative and qualitative analyses.
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Affiliation(s)
- Bastien Rigaud
- CLCC Eugène Marquis, University of Rennes, Inserm , Rennes , France
| | - Antoine Simon
- CLCC Eugène Marquis, University of Rennes, Inserm , Rennes , France
| | - Joël Castelli
- CLCC Eugène Marquis, University of Rennes, Inserm , Rennes , France
| | - Caroline Lafond
- CLCC Eugène Marquis, University of Rennes, Inserm , Rennes , France
| | - Oscar Acosta
- CLCC Eugène Marquis, University of Rennes, Inserm , Rennes , France
| | - Pascal Haigron
- CLCC Eugène Marquis, University of Rennes, Inserm , Rennes , France
| | - Guillaume Cazoulat
- Department of Imaging Physics, The University of Texas MD Anderson Cancer Center , Houston , TX , USA
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11
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Daniel M, Kuess P, Andrzejewski P, Nyholm T, Helbich T, Polanec S, Dragschitz F, Goldner G, Georg D, Baltzer P. Impact of androgen deprivation therapy on apparent diffusion coefficient and T2w MRI for histogram and texture analysis with respect to focal radiotherapy of prostate cancer. Strahlenther Onkol 2019; 195:402-411. [PMID: 30478670 PMCID: PMC6488548 DOI: 10.1007/s00066-018-1402-3] [Citation(s) in RCA: 8] [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: 07/10/2018] [Accepted: 11/12/2018] [Indexed: 12/20/2022]
Abstract
PURPOSE Accurate prostate cancer (PCa) detection is essential for planning focal external beam radiotherapy (EBRT). While biparametric MRI (bpMRI) including T2-weighted (T2w) and diffusion-weighted images (DWI) is an accurate tool to localize PCa, its value is less clear in the case of additional androgen deprivation therapy (ADT). The aim of this study was to investigate the value of a textural feature (TF) approach on bpMRI analysis in prostate cancer patients with and without neoadjuvant ADT with respect to future dose-painting applications. METHODS 28 PCa patients (54-80 years) with (n = 14) and without (n = 14) ADT who underwent bpMRI with T2w and DWI were analyzed retrospectively. Lesions, central gland (CG), and peripheral zone (PZ) were delineated by an experienced urogenital radiologist based on localized pre-therapeutic histopathology. Histogram parameters and 20 Haralick TF were calculated. Regional differences (i. e., tumor vs. PZ, tumor vs. CG) were analyzed for all imaging parameters. Receiver-operating characteristic (ROC) analysis was performed to measure diagnostic performance to distinguish PCa from benign prostate tissue and to identify the features with best discriminative power in both patient groups. RESULTS The obtained sensitivities were equivalent or superior when utilizing the TF in the no-ADT group, while specificity was higher for the histogram parameters. However, in the ADT group, TF outperformed the conventional histogram parameters in both specificity and sensitivity. Rule-in and rule-out criteria for ADT patients could exclusively be defined with the aid of TF. CONCLUSIONS The TF approach has the potential for quantitative image-assisted boost volume delineation in PCa patients even if they are undergoing neoadjuvant ADT.
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Affiliation(s)
- M Daniel
- Christian Doppler Laboratory for Medical Radiation Research for Radiation Oncology, Medical University of Vienna, Vienna, Austria.
- Department of Radiotherapy, Comprehensive Cancer Center, Medical University of Vienna/Vienna General Hospital, Vienna, Austria.
| | - P Kuess
- Christian Doppler Laboratory for Medical Radiation Research for Radiation Oncology, Medical University of Vienna, Vienna, Austria
- Department of Radiotherapy, Comprehensive Cancer Center, Medical University of Vienna/Vienna General Hospital, Vienna, Austria
| | - P Andrzejewski
- Christian Doppler Laboratory for Medical Radiation Research for Radiation Oncology, Medical University of Vienna, Vienna, Austria
- Medical Physics, EBG MedAustron GmbH, Wiener Neustadt, Austria
| | - T Nyholm
- Department of Radiation Sciences, Umeå University, Umeå, Sweden
| | - T Helbich
- Christian Doppler Laboratory for Medical Radiation Research for Radiation Oncology, Medical University of Vienna, Vienna, Austria
| | - S Polanec
- Christian Doppler Laboratory for Medical Radiation Research for Radiation Oncology, Medical University of Vienna, Vienna, Austria
- Department of Biomedical Imaging and Image-Guided Therapy, Medical University of Vienna/Vienna General Hospital, Vienna, Austria
| | - F Dragschitz
- Department of Radiotherapy, Comprehensive Cancer Center, Medical University of Vienna/Vienna General Hospital, Vienna, Austria
| | - G Goldner
- Department of Radiotherapy, Comprehensive Cancer Center, Medical University of Vienna/Vienna General Hospital, Vienna, Austria
| | - D Georg
- Christian Doppler Laboratory for Medical Radiation Research for Radiation Oncology, Medical University of Vienna, Vienna, Austria
- Department of Radiotherapy, Comprehensive Cancer Center, Medical University of Vienna/Vienna General Hospital, Vienna, Austria
| | - P Baltzer
- Christian Doppler Laboratory for Medical Radiation Research for Radiation Oncology, Medical University of Vienna, Vienna, Austria
- Department of Biomedical Imaging and Image-Guided Therapy, Medical University of Vienna/Vienna General Hospital, Vienna, Austria
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12
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Target definition in radiotherapy of prostate cancer using magnetic resonance imaging only workflow. PHYSICS & IMAGING IN RADIATION ONCOLOGY 2019; 9:89-91. [PMID: 33458431 PMCID: PMC7807603 DOI: 10.1016/j.phro.2019.03.004] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/02/2019] [Revised: 03/04/2019] [Accepted: 03/06/2019] [Indexed: 12/28/2022]
Abstract
In magnetic resonance (MR) only radiotherapy, the target delineation needs to be performed without computed tomography (CT). We investigated in thirteen patients with prostate cancer, how the clinical target volume (CTV) was affected, when the target delineation procedure was changed from using both CT and MR images to using MR images only. The mean volume of the CTVCT/MR was 61.0 cm3 as compared to 49.9 cm3 from MR-only based target delineation, corresponding to an average decrease of 18%. Our results show that CTVMR-only was consistently smaller than CTVCT/MR, which has to be taken into consideration before clinical commissioning of MR-only radiotherapy.
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13
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Wegener D, Zips D, Thorwarth D, Weiß J, Othman AE, Grosse U, Notohamiprodjo M, Nikolaou K, Müller AC. Precision of T2 TSE MRI-CT-image fusions based on gold fiducials and repetitive T2 TSE MRI-MRI-fusions for adaptive IGRT of prostate cancer by using phantom and patient data. Acta Oncol 2019; 58:88-94. [PMID: 30264629 DOI: 10.1080/0284186x.2018.1518594] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
INTRODUCTION To increase precision of radiation treatment (RT) delivery in prostate cancer, MRI-based RT as well as the use of fiducials like gold markers (GMs) have shown promising results. Their combined use is currently under investigation in clinical trials. Here, we aimed to evaluate a workflow of image registration based on GMs between CT and MRI as well as weekly MRI-MRI adaption based on T2 TSE sequence. MATERIAL AND METHODS A gel-phantom with two inserted GMs was scanned with CT and three different MR-scanners of 1.5 and 3 T (T2 TSE and T1 VIBE-Dixon, isotropic, voxel size 2 × 2 × 2 mm). After image fusion, deviations for fiducial and gel match were measured and artifacts were evaluated. Additionally, CT-MRI-match deviations and MRI-MRI-match deviations of 10 Patients from the M-basePro study using GMs were assessed. RESULTS GMs were visible in all imaging modalities. The outer gel contours were matched with <1 mm deviation, contour volumes varied between 0 and 1%. The deviations of the GMs were less than 2 mm in any direction of MRI/CT. Shifts of peripherally or centrally located GMs were randomly distributed. The average MRI-CT-match precision of 10 patients with GMs was 1.9 mm (range 1.1-3.1 mm). CONCLUSIONS Match inaccuracies for GMs between reference CT and voxel-isotropic T2-TSE sequences are small. Spatial deviations of CT- and MR-contoured fiducials were less than 2 mm, i.e., below SLT of the applied modalities. In patients, the average CT-MRI-match precision for GMs was 1.9 mm supporting their use in MR-guided high precision RT.
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Affiliation(s)
- D. Wegener
- Department of Radiation Oncology, University Hospital Tübingen, Eberhard Karls University Tübingen, Tübingen, Germany
| | - D. Zips
- Department of Radiation Oncology, University Hospital Tübingen, Eberhard Karls University Tübingen, Tübingen, Germany
- German Cancer Consortium (DKTK), Partner Site Tübingen; and German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - D. Thorwarth
- Section for Biomedical Physics, Department of Radiation Oncology, University Hospital Tübingen, Tübingen, Germany
- German Cancer Consortium (DKTK), Partner Site Tübingen; and German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - J. Weiß
- Department of Radiology, University Hospital Tübingen, Eberhard Karls University Tübingen, Tübingen, Germany
| | - A. E. Othman
- Department of Radiology, University Hospital Tübingen, Eberhard Karls University Tübingen, Tübingen, Germany
| | - U. Grosse
- Department of Radiology, University Hospital Tübingen, Eberhard Karls University Tübingen, Tübingen, Germany
| | - M. Notohamiprodjo
- Department of Radiology, University Hospital Tübingen, Eberhard Karls University Tübingen, Tübingen, Germany
| | - K. Nikolaou
- Department of Radiology, University Hospital Tübingen, Eberhard Karls University Tübingen, Tübingen, Germany
| | - A. C. Müller
- Department of Radiation Oncology, University Hospital Tübingen, Eberhard Karls University Tübingen, Tübingen, Germany
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Böckelmann F, Hammon M, Lettmaier S, Fietkau R, Bert C, Putz F. Penile bulb sparing in prostate cancer radiotherapy : Dose analysis of an in-house MRI system to improve contouring. Strahlenther Onkol 2018; 195:153-163. [PMID: 30315483 DOI: 10.1007/s00066-018-1377-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2018] [Accepted: 09/20/2018] [Indexed: 01/01/2023]
Abstract
OBJECTIVE This study aimed to assess the reduction in dose to the penile bulb (PB) achieved by MRI-based contouring following drinking and endorectal balloon (ERB) instructions. PATIENTS AND METHODS A total of 17 prostate cancer patients were treated with intensity-modulated radiation therapy (IMRT) and interstitial brachytherapy (IBT). CT and MRI datasets were acquired back-to-back based on a 65 cm3 air-filled ERB and drinking instructions. After rigid co-registration of the imaging data, the CT-based planning target volume (PTV) used for treatment planning was retrospectively compared to an MRI-based adaptive PTV and the dose to the PB was determined in each case. The adapted PTV encompassed a caudally cropped CT-based PTV which was defined on the basis of the MRI-based prostate contour plus an additional 5 mm safety margin. RESULTS In the seven-field IMRT treatment plans, the MRI-based adapted PTV achieved mean (Dmean) and maximum (Dmax) doses to the PB which were significantly lower (by 7.6 Gy and 10.9 Gy, respectively; p <0.05) than those of the CT-contoured PTV. For 6 patients, the estimated PB Dmax (seven-field IMRT and IBT) for the adapted PTV was <70 Gy, whereas only 1 patient fulfilled this criterium with the CT-based PTV. CONCLUSION MRI-based contouring and seven-field IMRT-based treatment planning achieved dose sparing to the PB. Whereas the comparison of MRI and CT contouring only relates to external beam radiotherapy (EBRT) sparing, considering EBRT and IBT shows the improvement in PB sparing for the total treatment.
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Affiliation(s)
- F Böckelmann
- Department of Radiation Oncology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Universitätsstraße 27, 91054, Erlangen, Germany
| | - M Hammon
- Department of Radiology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Maximiliansplatz 1, 91054, Erlangen, Germany
| | - S Lettmaier
- Department of Radiation Oncology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Universitätsstraße 27, 91054, Erlangen, Germany
| | - R Fietkau
- Department of Radiation Oncology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Universitätsstraße 27, 91054, Erlangen, Germany
| | - C Bert
- Department of Radiation Oncology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Universitätsstraße 27, 91054, Erlangen, Germany.
| | - F Putz
- Department of Radiation Oncology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Universitätsstraße 27, 91054, Erlangen, Germany
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15
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Tenhunen M, Korhonen J, Kapanen M, Seppälä T, Koivula L, Collan J, Saarilahti K, Visapää H. MRI-only based radiation therapy of prostate cancer: workflow and early clinical experience. Acta Oncol 2018; 57:902-907. [PMID: 29488426 DOI: 10.1080/0284186x.2018.1445284] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
BACKGROUND Magnetic resonance imaging (MRI) is the most comprehensive imaging modality for radiation therapy (RT) target delineation of most soft tissue tumors including prostate cancer. We have earlier presented step by step the MRI-only based workflow for RT planning and image guidance for localized prostate cancer. In this study we present early clinical experiences of MRI-only based planning. MATERIAL AND METHODS We have analyzed the technical planning workflow of the first 200 patients having received MRI-only planned radiation therapy for localized prostate cancer in Helsinki University Hospital Cancer center. Early prostate specific antigen (PSA) results were analyzed from n = 125 MRI-only patients (n = 25 RT only, n = 100 hormone treatment + RT) and were compared with the corresponding computed tomography (CT) planned patient group. RESULTS Technically the MRI-only planning procedure was suitable for 92% of the patients, only 8% of the patients required supplemental CT imaging. Early PSA response in the MRI-only planned group showed similar treatment results compared with the CT planned group and with an equal toxicity level. CONCLUSION Based on this retrospective study, MRI-only planning procedure is an effective and safe way to perform RT for localized prostate cancer. It is suitable for the majority of the patients.
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Affiliation(s)
- Mikko Tenhunen
- Cancer Centre, Helsinki University Hospital, Helsinki, Finland
| | - Juha Korhonen
- Cancer Centre, Helsinki University Hospital, Helsinki, Finland
| | - Mika Kapanen
- Cancer Centre, Helsinki University Hospital, Helsinki, Finland
| | - Tiina Seppälä
- Cancer Centre, Helsinki University Hospital, Helsinki, Finland
| | - Lauri Koivula
- Cancer Centre, Helsinki University Hospital, Helsinki, Finland
| | - Juhani Collan
- Cancer Centre, Helsinki University Hospital, Helsinki, Finland
| | | | - Harri Visapää
- Cancer Centre, Helsinki University Hospital, Helsinki, Finland
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16
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Henderson DR, Tree AC, Harrington KJ, van As NJ. Dosimetric Implications of Computerised Tomography-Only versus Magnetic Resonance-Fusion Contouring in Stereotactic Body Radiotherapy for Prostate Cancer. MEDICINES (BASEL, SWITZERLAND) 2018; 5:E32. [PMID: 29621134 PMCID: PMC6023312 DOI: 10.3390/medicines5020032] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/31/2018] [Revised: 04/02/2018] [Accepted: 04/03/2018] [Indexed: 12/31/2022]
Abstract
Background: Magnetic resonance (MR)-fusion contouring is the standard of care in prostate stereotactic body radiotherapy (SBRT) for target volume localisation. However, the planning computerised tomography (CT) scan continues to be used for dose calculation and treatment planning and verification. Discrepancies between the planning MR and CT scans may negate the benefits of MR-fusion contouring and it adds a significant resource burden. We aimed to determine whether CT-only contouring resulted in a dosimetric detriment compared with MR-fusion contouring in prostate SBRT planning. Methods: We retrospectively compared target volumes and SBRT plans for 20 patients treated clinically with MR-fusion contouring (standard of care) with those produced by re-contouring using CT data only. Dose was 36.25 Gy in 5 fractions. CT-only contouring was done on two occasions blind to MR data and reviewed by a separate observer. Primary outcome was the difference in rectal volume receiving 36 Gy or above. Results: Absolute target volumes were similar: 63.5 cc (SD ± 27.9) versus 63.2 (SD ± 26.5), Dice coefficient 0.86 (SD ± 0.04). Mean difference in apex superior-inferior position was 1.1 (SD ± 3.5; CI: −0.4–2.6). Small dosimetric differences in favour of CT-only contours were seen, with the mean rectal V36 Gy 0.3 cc (95% CI: 0.1–0.5) lower for CT-only contouring. Conclusions: Prostate SBRT can be successfully planned without MR-fusion contouring. Consideration can be given to omitting MR-fusion from the prostate SBRT workflow, provided reference to diagnostic MR imaging is available. Development of MR-only work flow is a key research priority to gain access to the anatomical fidelity of MR imaging.
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Affiliation(s)
- Daniel R Henderson
- Royal Marsden Hospital, Fulham Road, London SW3 6JJ, UK.
- Institute of Cancer Research, 237 Fulham Road, London SW3 6JB, UK.
- The Cancer Centre, University Hospitals Birmingham, Mindelsohn Way, Edgbaston, Birmingham B15 2GW, UK.
| | - Alison C Tree
- Royal Marsden Hospital, Fulham Road, London SW3 6JJ, UK.
- Institute of Cancer Research, 237 Fulham Road, London SW3 6JB, UK.
| | - Kevin J Harrington
- Royal Marsden Hospital, Fulham Road, London SW3 6JJ, UK.
- Institute of Cancer Research, 237 Fulham Road, London SW3 6JB, UK.
| | - Nicholas J van As
- Royal Marsden Hospital, Fulham Road, London SW3 6JJ, UK.
- Institute of Cancer Research, 237 Fulham Road, London SW3 6JB, UK.
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Nyholm T, Svensson S, Andersson S, Jonsson J, Sohlin M, Gustafsson C, Kjellén E, Söderström K, Albertsson P, Blomqvist L, Zackrisson B, Olsson LE, Gunnlaugsson A. MR and CT data with multiobserver delineations of organs in the pelvic area-Part of the Gold Atlas project. Med Phys 2018; 45:1295-1300. [DOI: 10.1002/mp.12748] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2017] [Revised: 11/20/2017] [Accepted: 12/20/2017] [Indexed: 11/06/2022] Open
Affiliation(s)
- Tufve Nyholm
- Department of Radiation Sciences; Umeå University; Umeå Sweden
| | | | | | - Joakim Jonsson
- Department of Radiation Sciences; Umeå University; Umeå Sweden
| | - Maja Sohlin
- Department of Radiation Physics; Institute of Clinical Sciences; Sahlgrenska University Hospital; Göteborg Sweden
| | - Christian Gustafsson
- Department of Hematology, Oncology and Radiation Physics; Skåne University Hospital; Lund Sweden
- Department of Medical Physics; Lund University; Malmö Sweden
| | - Elisabeth Kjellén
- Department of Hematology, Oncology and Radiation Physics; Skåne University Hospital; Lund Sweden
| | | | - Per Albertsson
- Department of Oncology; Institute of Clinical Sciences; Sahlgrenska Academy; University of Gothenburg; Gothenburg Sweden
| | - Lennart Blomqvist
- Department of Radiation Sciences; Umeå University; Umeå Sweden
- Department of Molecular Medicine and Surgery; Karolinska Institutet; Stockholm Sweden
| | | | - Lars E. Olsson
- Department of Hematology, Oncology and Radiation Physics; Skåne University Hospital; Lund Sweden
| | - Adalsteinn Gunnlaugsson
- Department of Hematology, Oncology and Radiation Physics; Skåne University Hospital; Lund Sweden
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18
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Koivula L, Kapanen M, Seppälä T, Collan J, Dowling JA, Greer PB, Gustafsson C, Gunnlaugsson A, Olsson LE, Wee L, Korhonen J. Intensity-based dual model method for generation of synthetic CT images from standard T2-weighted MR images - Generalized technique for four different MR scanners. Radiother Oncol 2017; 125:411-419. [PMID: 29097012 DOI: 10.1016/j.radonc.2017.10.011] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2017] [Revised: 10/09/2017] [Accepted: 10/10/2017] [Indexed: 11/17/2022]
Abstract
BACKGROUND AND PURPOSE Recent studies have shown that it is possible to conduct entire radiotherapy treatment planning (RTP) workflow using only MR images. This study aims to develop a generalized intensity-based method to generate synthetic CT (sCT) images from standard T2-weighted (T2w) MR images of the pelvis. MATERIALS AND METHODS This study developed a generalized dual model HU conversion method to convert standard T2w MR image intensity values to synthetic HU values, separately inside and outside of atlas-segmented bone volume contour. The method was developed and evaluated with 20 and 35 prostate cancer patients, respectively. MR images with scanning sequences in clinical use were acquired with four different MR scanners of three vendors. RESULTS For the generated synthetic CT (sCT) images of the 35 prostate patients, the mean (and maximal) HU differences in soft and bony tissue volumes were 16 ± 6 HUs (34 HUs) and -46 ± 56 HUs (181 HUs), respectively, against the true CT images. The average of the PTV mean dose difference in sCTs compared to those in true CTs was -0.6 ± 0.4% (-1.3%). CONCLUSIONS The study provides a generalized method for sCT creation from standard T2w images of the pelvis. The method produced clinically acceptable dose calculation results for all the included scanners and MR sequences.
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Affiliation(s)
- Lauri Koivula
- Department of Radiation Oncology, Cancer Center, Helsinki University Central Hospital, Finland; Department of Physics, University of Helsinki, Finland; Medical Imaging and Radiation Therapy, Kymenlaakso Central Hospital, Kymenlaakso Social and Health Services (Carea), Kotka, Finland.
| | - Mika Kapanen
- Department of Medical Physics, Medical Imaging Center, Tampere University Hospital, Finland
| | - Tiina Seppälä
- Department of Radiation Oncology, Cancer Center, Helsinki University Central Hospital, Finland
| | - Juhani Collan
- Department of Radiation Oncology, Cancer Center, Helsinki University Central Hospital, Finland
| | - Jason A Dowling
- CSIRO Health and Biosecurity, The Australian e-Health & Research Centre, Herston, Australia
| | - Peter B Greer
- School of Mathematical and Physical Sciences, The University of Newcastle, Australia; Department of Radiation Oncology, Calvary Mater Newcastle Hospital, Australia
| | - Christian Gustafsson
- Department of Hematology, Oncology and Radiation Physics, Skåne University Hospital, Lund, Sweden; Department of Medical Physics, Lund University, Malmö, Sweden
| | - Adalsteinn Gunnlaugsson
- Department of Hematology, Oncology and Radiation Physics, Skåne University Hospital, Lund, Sweden
| | - Lars E Olsson
- Department of Medical Physics, Lund University, Malmö, Sweden; Department of Translational Sciences, Lund University, Skåne University Hospital, Malmö, Sweden
| | - Leonard Wee
- MAASTRO Clinic, School of Oncology and Developmental Biology, Maastricht University, The Netherlands; Department of Medical Physics, Oncology Services, Vejle Hospital, Denmark
| | - Juha Korhonen
- Department of Radiation Oncology, Cancer Center, Helsinki University Central Hospital, Finland; Medical Imaging and Radiation Therapy, Kymenlaakso Central Hospital, Kymenlaakso Social and Health Services (Carea), Kotka, Finland; Department of Radiology, Helsinki University Central Hospital, Finland; Department of Nuclear Medicine, Helsinki University Central Hospital, Finland
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Zhang X, Fu Z, Gong G, Wei H, Duan J, Chen Z, Chen X, Wang R, Yin Y. Implementation of diffusion-weighted magnetic resonance imaging in target delineation of central lung cancer accompanied with atelectasis in precision radiotherapy. Oncol Lett 2017; 14:2677-2682. [PMID: 28927030 PMCID: PMC5588085 DOI: 10.3892/ol.2017.6479] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2015] [Accepted: 04/21/2017] [Indexed: 12/28/2022] Open
Abstract
Radiotherapy, particularly the target delineation of cancer based on scanned images, plays a key role in the planning of cancer treatment. Recently, diffusion-weighted magnetic resonance imaging (DW-MRI) has emerged as a prospective superior procedure compared with intensified computed tomography (CT) and positron emission tomography (PET) in the target delineation of cancer. However, the implication of DW-MRI in lung cancer, the leading cause of cancer-associated mortality worldwide, has not been extensively evaluated. In the present study, the gross target volumes of lung cancer masses delineated using the DW-MRI, CT and PET procedures were compared in a pairwise manner in a group of 27 lung cancer patients accompanied with atelectasis of various levels. The data showed that compared with CT and PET procedures, DW-MRI has a more precise delineation of lung cancer while exhibiting higher reproducibility. Together with the fact that it is non-invasive and cost-effective, these data demonstrate the great application potential of the DW-MRI procedure in cancer precision radiotherapy.
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Affiliation(s)
- Xinli Zhang
- Department of Radiation Oncology, Shandong Cancer Hospital and Institute, Shandong University, Jinan, Shandong 250117, P.R. China.,Department of Medical Oncology, Tai'an City Central Hospital, Tai'an, Shandong 271000, P.R. China
| | - Zheng Fu
- Department of Radiation Oncology, Shandong Cancer Hospital and Institute, Shandong University, Jinan, Shandong 250117, P.R. China
| | - Guanzhong Gong
- Department of Radiation Oncology, Shandong Cancer Hospital and Institute, Shandong University, Jinan, Shandong 250117, P.R. China
| | - Hong Wei
- Department of Radiation Oncology, Shandong Cancer Hospital and Institute, Shandong University, Jinan, Shandong 250117, P.R. China
| | - Jinghao Duan
- Department of Radiation Oncology, Shandong Cancer Hospital and Institute, Shandong University, Jinan, Shandong 250117, P.R. China
| | - Zhaoqiu Chen
- Department of Radiation Oncology, Shandong Cancer Hospital and Institute, Shandong University, Jinan, Shandong 250117, P.R. China
| | - Xiangming Chen
- Department of Medical Oncology, Tai'an City Central Hospital, Tai'an, Shandong 271000, P.R. China
| | - Ruozheng Wang
- Department of Radiation Oncology, Affiliated Tumor Hospital of Xinjiang Medical University, Urumqi, Xinjiang 830011, P.R. China
| | - Yong Yin
- Department of Radiation Oncology, Shandong Cancer Hospital and Institute, Shandong University, Jinan, Shandong 250117, P.R. China
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Koivula L, Wee L, Korhonen J. Feasibility of MRI-only treatment planning for proton therapy in brain and prostate cancers: Dose calculation accuracy in substitute CT images. Med Phys 2017; 43:4634. [PMID: 27487880 DOI: 10.1118/1.4958677] [Citation(s) in RCA: 60] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
PURPOSE Magnetic resonance imaging (MRI) is increasingly used for radiotherapy target delineation, image guidance, and treatment response monitoring. Recent studies have shown that an entire external x-ray radiotherapy treatment planning (RTP) workflow for brain tumor or prostate cancer patients based only on MRI reference images is feasible. This study aims to show that a MRI-only based RTP workflow is also feasible for proton beam therapy plans generated in MRI-based substitute computed tomography (sCT) images of the head and the pelvis. METHODS The sCTs were constructed for ten prostate cancer and ten brain tumor patients primarily by transforming the intensity values of in-phase MR images to Hounsfield units (HUs) with a dual model HU conversion technique to enable heterogeneous tissue representation. HU conversion models for the pelvis were adopted from previous studies, further extended in this study also for head MRI by generating anatomical site-specific conversion models (a new training data set of ten other brain patients). This study also evaluated two other types of simplified sCT: dual bulk density (for bone and water) and homogeneous (water only). For every clinical case, intensity modulated proton therapy (IMPT) plans robustly optimized in standard planning CTs were calculated in sCT for evaluation, and vice versa. Overall dose agreement was evaluated using dose-volume histogram parameters and 3D gamma criteria. RESULTS In heterogeneous sCTs, the mean absolute errors in HUs were 34 (soft tissues: 13, bones: 92) and 42 (soft tissues: 9, bones: 97) in the head and in the pelvis, respectively. The maximum absolute dose differences relative to CT in the brain tumor clinical target volume (CTV) were 1.4% for heterogeneous sCT, 1.8% for dual bulk sCT, and 8.9% for homogenous sCT. The corresponding maximum differences in the prostate CTV were 0.6%, 1.2%, and 3.6%, respectively. The percentages of dose points in the head and pelvis passing 1% and 1 mm gamma index criteria were over 91%, 85%, and 38% with heterogeneous, dual bulk, and homogeneous sCTs, respectively. There were no significant changes to gamma index pass rates for IMPT plans first optimized in CT and then calculated in heterogeneous sCT versus IMPT plans first optimized in heterogeneous sCT and then calculated on standard CT. CONCLUSIONS This study demonstrates that proton therapy dose calculations on heterogeneous sCTs are in good agreement with plans generated with standard planning CT. An MRI-only based RTP workflow is feasible in IMPT for brain tumors and prostate cancers.
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Affiliation(s)
- Lauri Koivula
- Department of Radiation Oncology, Comprehensive Cancer Center, Helsinki University Central Hospital, P.O. Box 180, Helsinki 00029 HUS, Finland and Department of Medical Physics, Oncology Services, Vejle Hospital, Kabbeltoft 25, Vejle DK-7100, Denmark
| | - Leonard Wee
- Department of Medical Physics, Oncology Services, Vejle Hospital, Kabbeltoft 25, Vejle DK-7100, Denmark and Danish Colorectal Cancer Centre South, Vejle Hospital, Kabbeltoft 25, Vejle DK-7100, Denmark
| | - Juha Korhonen
- Department of Radiation Oncology, Comprehensive Cancer Center, Helsinki University Central Hospital, P.O. Box 180, Helsinki 00029 HUS, Finland; Danish Colorectal Cancer Centre South, Vejle Hospital, Kabbeltoft 25, Vejle DK-7100, Denmark; and Department of Radiology, Helsinki University Central Hospital, P.O. Box 180, Helsinki 00029 HUS, Finland
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Prostate Cancer Radiation Therapy: What Do Clinicians Have to Know? BIOMED RESEARCH INTERNATIONAL 2016; 2016:6829875. [PMID: 28116302 PMCID: PMC5225325 DOI: 10.1155/2016/6829875] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/31/2016] [Revised: 10/18/2016] [Accepted: 10/31/2016] [Indexed: 12/11/2022]
Abstract
Radiotherapy (RT) for prostate cancer (PC) has steadily evolved over the last decades, with improving biochemical disease-free survival. Recently population based research also revealed an association between overall survival and doses ≥ 75.6 Gray (Gy) in men with intermediate- and high-risk PC. Examples of improved RT techniques are image-guided RT, intensity-modulated RT, volumetric modulated arc therapy, and stereotactic ablative body RT, which could facilitate further dose escalation. Brachytherapy is an internal form of RT that also developed substantially. New devices such as rectum spacers and balloons have been developed to spare rectal structures. Newer techniques like protons and carbon ions have the intrinsic characteristics maximising the dose on the tumour while minimising the effect on the surrounding healthy tissue, but clinical data are needed for confirmation in randomised phase III trials. Furthermore, it provides an overview of an important discussion issue in PC treatment between urologists and radiation oncologists: the comparison between radical prostatectomy and RT. Current literature reveals that all possible treatment modalities have the same cure rate, but a different toxicity pattern. We recommend proposing the possible different treatment modalities with their own advantages and side-effects to the individual patient. Clinicians and patients should make treatment decisions together (shared decision-making) while using patient decision aids.
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Commandeur F, Simon A, Mathieu R, Nassef M, Arango JDO, Rolland Y, Haigron P, de Crevoisier R, Acosta O. MRI to CT Prostate Registration for Improved Targeting in Cancer External Beam Radiotherapy. IEEE J Biomed Health Inform 2016; 21:1015-1026. [PMID: 27333613 DOI: 10.1109/jbhi.2016.2581881] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
External radiotherapy is a major clinical treatment for localized prostate cancer. Currently, computed tomography (CT) is used to delineate the prostate and to plan the radiotherapy treatment. However, CT images suffer from a poor soft-tissue contrast and do not allow an accurate organ delineation. On the contrary, magnetic resonance imaging (MRI) provides rich details and high soft-tissue contrast, allowing tumor detection. Thus, the intraindividual propagation of MRI delineations toward the planning CT may improve tumor targeting. In this paper, we introduce a new method to propagate MRI prostate delineations to the planning CT. In the first step, a random forest classification is performed to coarsely detect the prostate in the CT images, yielding a prostate probability membership for each voxel and a prostate hard segmentation. Then, the registration is performed using a new similarity metric which maximizes the probability and the collinearity between the normals of the manual registration (MR) existing contour and the contour resulting from the CT classification. The first study on synthetic data was performed to analyze the influence of the metric parameters with different levels of noise. Then, the method was also evaluated on real MR-CT data using manual alignments and intraprostatic fiducial markers and compared to a classically used mutual information (MI) approach. The proposed metric outperformed MI by 7% in terms of Dice score coefficient, by 3.14 mm the Hausdorff distance, and 2.13 mm the markers position errors. Finally, the impact of registration uncertainties on the treatment planning was evaluated, demonstrating the potential advantage of the proposed approach in a clinical setup to define a precise target.
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