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Oh G, Lee J, Kim H, Kim W, Kang S, Chung J, Jeong S, Lee H, Yoon M, Lee B. Monte Carlo simulation study of an in vivo four-dimensional tracking system with a diverging collimator for monitoring radiation source (Ir-192) location during brachytherapy: proof of concept and feasibility. Front Physiol 2024; 15:1302301. [PMID: 38590693 PMCID: PMC10999580 DOI: 10.3389/fphys.2024.1302301] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Accepted: 01/09/2024] [Indexed: 04/10/2024] Open
Abstract
Introduction: The aim of this study was to demonstrate the potential of an in vivo four-dimensional (4D) tracking system to accurately localize the radiation source, Iridium-192 (Ir-192) in high-dose rate brachytherapy. Methods: To achieve time-dependent 3D positioning of the Ir-192 source, we devised a 4D tracking system employing multiple compact detectors. During the system's design phase, we conducted comprehensive optimization and analytical evaluations of the diverging collimator employed for detection purposes. Subsequently, we executed 3D reconstruction and positioning procedures based on the 2D images obtained by six detectors, each equipped with an optimized diverging collimator. All simulations for designing and evaluating the 4D tracking system were performed using the open-source GATE (v9.1) Monte Carlo platform based on the GEANT4 (v10.7) toolkit. In addition, to evaluate the accuracy of the proposed 4D tracking system, we conducted simulations and 3D positioning using a solid phantom and patient data. Finally, the error between the reconstructed position coordinates determined by the tracking system and the original coordinates of the Ir-192 radiation source was analyzed. Results: The parameters for the optimized diverging collimator were a septal thickness of 0.3 mm and a collimator height of 30 mm. A tracking system comprising 6 compact detectors was designed and implemented utilizing this collimator. Analysis of the accuracy of the proposed Ir-192 source tracking system found that the average of the absolute values of the error between the 3D reconstructed and original positions for the simulation with the solid phantom were 0.440 mm for the x coordinate, 0.423 mm for the y coordinate, and 0.764 mm for the z coordinate, and the average Euclidean distance was 1.146 mm. Finally, in a simulation based on data from a patient who underwent brachytherapy, the average Euclidean distance between the original and reconstructed source position was 0.586 mm. Discussion: These results indicated that the newly designed in vivo 4D tracking system for monitoring the Ir-192 source during brachytherapy could determine the 3D position of the radiation source in real time during treatment. We conclude that the proposed positioning system has the potential to make brachytherapy more accurate and reliable.
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Affiliation(s)
- Geon Oh
- Department of Bioengineering, College of Health Sciences, Korea University, Seoul, Republic of Korea
- Department of Radiation Oncology, Inha University Hospital, Incheon, Republic of Korea
| | - Jeongshim Lee
- Department of Radiation Oncology, Inha University Hospital, Incheon, Republic of Korea
| | - Hunjung Kim
- Department of Radiation Oncology, Inha University Hospital, Incheon, Republic of Korea
| | - Woochul Kim
- Department of Radiation Oncology, Inha University Hospital, Incheon, Republic of Korea
| | - Sangwon Kang
- Department of Radiation Oncology, Seoul National University Bundang Hospital, Seongnam, Gyeonggi, Republic of Korea
| | - Jinbeom Chung
- Department of Radiation Oncology, Seoul National University Bundang Hospital, Seongnam, Gyeonggi, Republic of Korea
| | - Seonghoon Jeong
- Department of Neurology, Inje University Ilsan Paik Hospital, Goyang, Gyeonggi, Republic of Korea
| | - Hakjae Lee
- ARALE Laboratory Co., Ltd., Seoul, Republic of Korea
| | - Myonggeun Yoon
- Department of Bioengineering, College of Health Sciences, Korea University, Seoul, Republic of Korea
| | - Boram Lee
- Department of Radiation Oncology, Inha University Hospital, Incheon, Republic of Korea
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Nakanishi K, Yamamoto S, Yabe T, Yogo K, Noguchi Y, Okudaira K, Kawachi N, Kataoka J. Estimating blurless and noise-free Ir-192 source images from gamma camera images for high-dose-rate brachytherapy using a deep-learning approach. Biomed Phys Eng Express 2023; 10:015006. [PMID: 37948761 DOI: 10.1088/2057-1976/ad0bb2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2023] [Accepted: 11/10/2023] [Indexed: 11/12/2023]
Abstract
Objective. Precise monitoring of the position and dwell time of iridium-192 (Ir-192) during high-dose-rate (HDR) brachytherapy is crucial to avoid serious damage to normal tissues. Source imaging using a compact gamma camera is a potential approach for monitoring. However, images from the gamma camera are affected by blurring and statistical noise, which impact the accuracy of source position monitoring. This study aimed to develop a deep-learning approach for estimating ideal source images that reduce the effect of blurring and statistical noise from experimental images captured using a compact gamma camera.Approach. A double pix2pix model was trained using the simulated gamma camera images of an Ir-192 source. The first model was responsible for denoising the Ir-192 images, whereas the second model performed super resolution. Trained models were then applied to the experimental images to estimate the ideal images.Main results. At a distance of 100 mm between the compact gamma camera and the Ir-192 source, the difference in full width at half maximum (FWHM) between the estimated and actual source sizes was approximately 0.5 mm for a measurement time of 1.5 s. This difference has been improved from approximately 2.7 mm without the use of DL. Even with a measurement time of 0.1 s, the ideal images could be estimated as accurately as in the 1.5 s measurements. This method consistently achieved accurate estimations of the source images at any position within the field of view; however, the difference increased with the distance between the Ir-192 source and the compact gamma camera.Significance. The proposed method successfully provided estimated images from the experimental images within errors smaller than 0.5 mm at 100 mm. This method is promising for reducing blurring and statistical noise from the experimental images, enabling precise real-time monitoring of Ir-192 sources during HDR brachytherapy.
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Affiliation(s)
- Kohei Nakanishi
- Department of Integrated Health Science, Nagoya University Graduate School of Medicine, Japan
| | | | - Takuya Yabe
- Takasaki Institute for Advanced Quantum Science, Foundational Quantum Technology Research Directorate, National Institutes for Quantum Science and Technology (QST), Japan
| | - Katsunori Yogo
- Department of Integrated Health Science, Nagoya University Graduate School of Medicine, Japan
| | - Yumiko Noguchi
- Department of Radiological Technology, Nagoya University Hospital, Japan
| | - Kuniyasu Okudaira
- Department of Radiological Technology, Nagoya University Hospital, Japan
| | - Naoki Kawachi
- Takasaki Institute for Advanced Quantum Science, Foundational Quantum Technology Research Directorate, National Institutes for Quantum Science and Technology (QST), Japan
| | - Jun Kataoka
- Faculty of Science and Engineering, Waseda University, Japan
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Dürrbeck C, Schulz M, Pflaum L, Kallis K, Geimer T, Abu-Hossin N, Strnad V, Maier A, Fietkau R, Bert C. Estimating follow-up CTs from geometric deformations of catheter implants in interstitial breast brachytherapy: A feasibility study using electromagnetic tracking. Med Phys 2023; 50:5793-5805. [PMID: 37540071 DOI: 10.1002/mp.16659] [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: 11/10/2022] [Revised: 06/20/2023] [Accepted: 07/21/2023] [Indexed: 08/05/2023] Open
Abstract
BACKGROUND Electromagnetic tracking (EMT) systems have been shown to provide valuable information on the geometry of catheter implants in breast cancer patients undergoing interstitial brachytherapy (iBT). In the context of an extended patient-specific, pre-treatment verification, EMT can play a key role in determining the potential need and, if applicable, the appropriate time for treatment adaptation. To detect dosimetric shortcomings the relative position between catheters, and target volume and critical structures must be known. Since EMT cannot provide the anatomical context and standard imaging techniques such as cone-beam CT are not yet available in most brachytherapy suites, it is not possible to detect anatomic changes on a daily or fraction basis, so the need for adaptive planning cannot be identified. PURPOSE The aim of this feasibility study is to develop and evaluate a technique capable of estimating follow-up CTs at any time based on the initial treatment planning CT (PCT) and surrogate information about changes of the implant geometry from an EMT system. METHODS A deformation vector field is calculated from two different implant reconstructions acquired in treatment position through EMT, the first immediately after the PCT and the second at another time point during the course of treatment. The calculation is based on discrete displacement vectors of pairs of control and target points. These are extrapolated by means of different radial basis functions in order to cover the entire CT volume. The adequate parameters for the calculation of the deformation field were identified. By warping the PCT according to the deformation field, one obtains an estimated CT (ECT) that reflects the geometric changes. For the proof of concept, ECTs were computed for the time point of the clinical follow-up CT (FCT) that is embedded in the treatment workflow after the fourth fraction. RESULTS ECT and clinical FCTs of 20 patients were compared to each other quantitatively in terms of absolute Hounsfield unit differences in the planning target volume (PTV) and in a convex hull (CH) enclosing the catheters. The median differences were 31.2 and 29.5 HU for the CH and the PTV, respectively. CONCLUSION The proposed ECT approach was able to approximate the "anatomy of the day" and therefore, in principle, allows a dosimetric appraisal of the treatment plan quality before each fraction. In this way, it can contribute to a more detailed patient-specific quality assurance in iBT of the breast and help to identify the timing for a potential treatment adaptation.
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Affiliation(s)
- Christopher Dürrbeck
- Department of Radiation Oncology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany
- Comprehensive Cancer Center Erlangen-EMN (CCC ER-EMN), Erlangen, Germany
| | - Moritz Schulz
- Department of Radiation Oncology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany
- Comprehensive Cancer Center Erlangen-EMN (CCC ER-EMN), Erlangen, Germany
| | - Leonie Pflaum
- Department of Radiation Oncology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany
- Comprehensive Cancer Center Erlangen-EMN (CCC ER-EMN), Erlangen, Germany
- Pattern Recognition Lab, FAU, Erlangen, Germany
| | - Karoline Kallis
- Department of Radiation Oncology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany
| | - Tobias Geimer
- Department of Radiation Oncology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany
- Pattern Recognition Lab, FAU, Erlangen, Germany
| | - Nadin Abu-Hossin
- Department of Radiation Oncology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany
- Comprehensive Cancer Center Erlangen-EMN (CCC ER-EMN), Erlangen, Germany
| | - Vratislav Strnad
- Department of Radiation Oncology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany
- Comprehensive Cancer Center Erlangen-EMN (CCC ER-EMN), Erlangen, Germany
| | | | - Rainer Fietkau
- Department of Radiation Oncology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany
- Comprehensive Cancer Center Erlangen-EMN (CCC ER-EMN), Erlangen, Germany
| | - Christoph Bert
- Department of Radiation Oncology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany
- Comprehensive Cancer Center Erlangen-EMN (CCC ER-EMN), Erlangen, Germany
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Sung S, Lee M, Choi HJ, Park H, Cheon BW, Min CH, Yeom YS, Kim H, You SH, Choi HJ. Feasibility of internal-source tracking with C-arm CT/SPECT imaging with limited-angle projection data for online in vivo dose verification in brachytherapy: A Monte Carlo simulation study. Brachytherapy 2023; 22:673-685. [PMID: 37301703 DOI: 10.1016/j.brachy.2023.05.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2022] [Revised: 03/13/2023] [Accepted: 05/07/2023] [Indexed: 06/12/2023]
Abstract
PURPOSE The current protocol for use of the image-guided adaptive brachytherapy (IGABT) procedure entails transport of a patient between the treatment room and the 3-D tomographic imaging room after implantation of the applicators in the body, which movement can cause position displacement of the applicator. Moreover, it is not possible to track 3-D radioactive source movement inside the body, even though there can be significant inter- and intra-fractional patient-setup changes. In this paper, therefore, we propose an online single-photon emission computed tomography (SPECT) imaging technique with a combined C-arm fluoroscopy X-ray system and attachable parallel-hole collimator for internal radioactive source tracking of every source position in the applicator. METHODS AND MATERIALS In the present study, using Geant4 Monte Carlo (MC) simulation, the feasibility of high-energy gamma detection with a flat-panel detector for X-ray imaging was assessed. Further, a parallel-hole collimator geometry was designed based on an evaluation of projection image quality for a 192Ir point source, and 3-D limited-angle SPECT-image-based source-tracking performances were evaluated for various source intensities and positions. RESULTS The detector module attached to the collimator could discriminate the 192Ir point source with about 3.4% detection efficiency when including the total counts in the entire deposited energy region. As the result of collimator optimization, hole size, thickness, and length were determined to be 0.5, 0.2, and 45 mm, respectively. Accordingly, the source intensities and positions also were successfully tracked with the 3-D SPECT imaging system when the C-arm was rotated within 110° in 2 seconds. CONCLUSIONS We expect that this system can be effectively implemented for online IGABT and in vivo patient dose verification.
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Affiliation(s)
- Saerom Sung
- Department of Radiation Convergence Engineering, Yonsei University, Wonju-si, Gangwon-do, Republic of Korea
| | - Minjae Lee
- Department of Radiation Convergence Engineering, Yonsei University, Wonju-si, Gangwon-do, Republic of Korea
| | - Hyung-Joo Choi
- Department of Radiation Convergence Engineering, Yonsei University, Wonju-si, Gangwon-do, Republic of Korea
| | - Hyojun Park
- Department of Radiation Convergence Engineering, Yonsei University, Wonju-si, Gangwon-do, Republic of Korea
| | - Bo-Wi Cheon
- Department of Radiation Convergence Engineering, Yonsei University, Wonju-si, Gangwon-do, Republic of Korea
| | - Chul Hee Min
- Department of Radiation Convergence Engineering, Yonsei University, Wonju-si, Gangwon-do, Republic of Korea
| | - Yeon Soo Yeom
- Department of Radiation Convergence Engineering, Yonsei University, Wonju-si, Gangwon-do, Republic of Korea
| | - Hyemi Kim
- Department of Radiation Oncology, Wonju Severance Christian Hospital, Yonsei University Wonju College of Medicine, Wonju-si, Gangwon-do, Republic of Korea
| | - Sei Hwan You
- Department of Radiation Oncology, Wonju Severance Christian Hospital, Yonsei University Wonju College of Medicine, Wonju-si, Gangwon-do, Republic of Korea
| | - Hyun Joon Choi
- Department of Radiation Oncology, Wonju Severance Christian Hospital, Yonsei University Wonju College of Medicine, Wonju-si, Gangwon-do, Republic of Korea.
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Vasyltsiv R, Qian X, Xu Z, Ryu S, Zhao W, Howansky A. Feasibility of 4D HDR brachytherapy source tracking using x-ray tomosynthesis: Monte Carlo investigation. Med Phys 2023; 50:4695-4709. [PMID: 37402139 DOI: 10.1002/mp.16579] [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: 01/04/2023] [Revised: 05/16/2023] [Accepted: 06/11/2023] [Indexed: 07/05/2023] Open
Abstract
PURPOSE High dose rate (HDR) brachytherapy rapidly delivers dose to targets with steep dose gradients. This treatment method must adhere to prescribed treatment plans with high spatiotemporal accuracy and precision, as failure to do so may degrade clinical outcomes. One approach to achieving this goal is to develop imaging techniques to track HDR sources in vivo in reference to surrounding anatomy. This work investigates the feasibility of using an isocentric C-arm x-ray imager and tomosynthesis methods to track Ir-192 HDR brachytherapy sources in vivo over time (4D). METHODS A tomosynthesis imaging workflow was proposed and its achievable source detectability, localization accuracy, and spatiotemporal resolution were investigated in silico. An anthropomorphic female XCAT phantom was modified to include a vaginal cylinder applicator and Ir-192 HDR source (0.5 × 0.5 × 5.0 mm3 ), and the workflow was carried out using the MC-GPU Monte Carlo image simulation platform. Source detectability was characterized using the reconstructed source signal-difference-to-noise-ratio (SDNR), localization accuracy by the absolute 3D error in its measured centroid location, and spatiotemporal resolution by the full-width-at-half-maximum (FWHM) of line profiles through the source in each spatial dimension considering a maximum C-arm angular velocity of 30° per second. The dependence of these parameters on acquisition angular range (θtot = 0°-90°), number of views, angular increment between views (Δθ = 0°-15°), and volumetric constraints imposed in reconstruction was evaluated. Organ voxel doses were tallied to derive the workflow's attributable effective dose. RESULTS The HDR source was readily detected and its centroid was accurately localized with the proposed workflow and method (SDNR: 10-40, 3D error: 0-0.144 mm). Tradeoffs were demonstrated for various combinations of image acquisition parameters; namely, increasing the tomosynthesis acquisition angular range improved resolution in the depth-encoded direction, for example from 2.5 mm to 1.2 mm between θtot = 30o and θtot = 90o , at the cost of increasing acquisition time from 1 to 3 s. The best-performing acquisition parameters (θtot = 90o , Δθ = 1°) yielded no centroid localization error, and achieved submillimeter source resolution (0.57 × 1.21 × 5.04 mm3 apparent source dimensions, FWHM). The total effective dose for the workflow was 263 µSv for its required pre-treatment imaging component and 7.59 µSv per mid-treatment acquisition thereafter, which is comparable to common diagnostic radiology exams. CONCLUSIONS A system and method for tracking HDR brachytherapy sources in vivo using C-arm tomosynthesis was proposed and its performance investigated in silico. Tradeoffs in source conspicuity, localization accuracy, spatiotemporal resolution, and dose were determined. The results suggest this approach is feasible for localizing an Ir-192 HDR source in vivo with submillimeter spatial resolution, 1-3 second temporal resolution and minimal additional dose burden.
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Affiliation(s)
- Roman Vasyltsiv
- Department of Radiology, Stony Brook University, Health Sciences Center L4-120, Stony Brook, New York, USA
| | - Xin Qian
- Department of Radiation Oncology, Stony Brook University, Health Sciences Center L2, Stony Brook, New York, USA
| | - Zhigang Xu
- Department of Radiation Oncology, Stony Brook University, Health Sciences Center L2, Stony Brook, New York, USA
| | - Samuel Ryu
- Department of Radiation Oncology, Stony Brook University, Health Sciences Center L2, Stony Brook, New York, USA
| | - Wei Zhao
- Department of Radiology, Stony Brook University, Health Sciences Center L4-120, Stony Brook, New York, USA
| | - Adrian Howansky
- Department of Radiology, Stony Brook University, Health Sciences Center L4-120, Stony Brook, New York, USA
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Richardson SL, Buzurovic IM, Cohen GN, Culberson WS, Dempsey C, Libby B, Melhus CS, Miller RA, Scanderbeg DJ, Simiele SJ. AAPM medical physics practice guideline 13.a: HDR brachytherapy, part A. J Appl Clin Med Phys 2023; 24:e13829. [PMID: 36808798 PMCID: PMC10018677 DOI: 10.1002/acm2.13829] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Revised: 08/09/2022] [Accepted: 09/22/2022] [Indexed: 02/22/2023] Open
Abstract
The American Association of Physicists in Medicine (AAPM) is a nonprofit professional society whose primary purposes are to advance the science, education, and professional practice of medical physics. The AAPM has more than 8000 members and is the principal organization of medical physicists in the United States. The AAPM will periodically define new practice guidelines for medical physics practice to help advance the science of medical physics and to improve the quality of service to patients throughout the United States. Existing medical physics practice guidelines (MPPGs) will be reviewed for the purpose of revision or renewal, as appropriate, on their fifth anniversary or sooner. Each medical physics practice guideline represents a policy statement by the AAPM, has undergone a thorough consensus process in which it has been subjected to extensive review, and requires the approval of the Professional Council. The medical physics practice guidelines recognize that the safe and effective use of diagnostic and therapeutic radiology requires specific training, skills, and techniques, as described in each document. Reproduction or modification of the published practice guidelines and technical standards by those entities not providing these services is not authorized. The following terms are used in the AAPM practice guidelines: (1) Must and must not: Used to indicate that adherence to the recommendation is considered necessary to conform to this practice guideline. (2) Should and should not: Used to indicate a prudent practice to which exceptions may occasionally be made in appropriate circumstances. Approved by AAPM's Executive Committee April 28, 2022.
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Affiliation(s)
| | - Ivan M Buzurovic
- Brigham & Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Gil'ad N Cohen
- Memorial Sloan-Kettering Cancer Center, New York, NY, USA
| | | | - Claire Dempsey
- Calvary Mater Newcastle Hospital University of Newcastle, Callaghan, Australia University of Washington, Seattle, USA
| | | | | | - Robin A Miller
- Multicare Regional Cancer Center, Northwest Medical Physics Center, Tacoma, WA, USA
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Fiber-Optic Based Laser Wakefield Accelerated Electron Beams and Potential Applications in Radiotherapy Cancer Treatments. PHOTONICS 2022. [DOI: 10.3390/photonics9060403] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Ultra-compact electron beam technology based on laser wakefield acceleration (LWFA) could have a significant impact on radiotherapy treatments. Recent developments in LWFA high-density regime (HD-LWFA) and low-intensity fiber optically transmitted laser beams could allow for cancer treatments with electron beams from a miniature electronic source. Moreover, an electron beam emitted from a tip of a fiber optic channel could lead to new endoscopy-based radiotherapy, which is not currently available. Low-energy (10 keV–1 MeV) LWFA electron beams can be produced by irradiating high-density nano-materials with a low-intensity laser in the range of ~1014 W/cm2. This energy range could be useful in radiotherapy and, specifically, brachytherapy for treating superficial, interstitial, intravascular, and intracavitary tumors. Furthermore, it could unveil the next generation of high-dose-rate brachytherapy systems that are not dependent on radioactive sources, do not require specially designed radiation-shielded rooms for treatment, could be portable, could provide a selection of treatment energies, and would significantly reduce operating costs to a radiation oncology clinic.
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Hanna S, Lapuz C, Lim A. Gynecological intrauterine brachytherapy training for radiation therapists: The development and implementation of a training program. Brachytherapy 2022; 21:678-685. [PMID: 35672241 DOI: 10.1016/j.brachy.2022.03.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Accepted: 03/26/2022] [Indexed: 11/02/2022]
Abstract
PURPOSE Gynecological brachytherapy (GynBT) is an important part of gynecological cancer management. At Olivia Newton-John Cancer Wellness & Research Centre (ONJCWRC), Melbourne, Australia, radiation therapists (RTs) are integral to the MRI adaptive GynBT program workflow. However, there is limited GynBT training available for RTs in Australia. A GynBT training program has been developed at ONJCWRC to meet this need and support RTs in becoming competent, proficient and confident in the various roles in GynBT. This is a preliminary report on the development and implementation of a credentialing program, providing a structured approach to GynBT training of RTs. METHODS AND MATERIALS A credentialing program was designed with modules and competency assessments to ensure efficiency and proficiency of RTs in the GynBT workflow. The program includes theoretical modules in anatomy, international GynBT guidelines, radiation safety and local protocols; and practical modules in equipment, ultrasound for GynBT, operating theatre procedures, MRI, contouring, applicator reconstruction, planning, quality assurance and treatment delivery. Learning strategies include self-directed learning, tutorials, practical sessions, and third-party courses. The program concludes with an exit examination assessing major competencies. RESULTS The program was implemented in April 2018 with three RTs completing the program and passing the exit examination on first attempt. On post-program survey, the RTs felt the program was comprehensive, helping to build their confidence, and proficiency in GynBT. CONCLUSIONS A GynBT RT credentialing program was successfully developed and implemented to improve the quality of training at ONJCWRC. This program is mandatory for RTs joining the GynBT team. This program can provide a framework for implementation of GynBT training in other centers.
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Affiliation(s)
- Sylvia Hanna
- Department of Radiation Oncology, Olivia Newton-John Cancer Wellness & Research Centre, Austin Health, Melbourne, Australia.
| | - Carminia Lapuz
- Department of Radiation Oncology, Olivia Newton-John Cancer Wellness & Research Centre, Austin Health, Melbourne, Australia
| | - Adeline Lim
- Department of Radiation Oncology, Olivia Newton-John Cancer Wellness & Research Centre, Austin Health, Melbourne, Australia
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In Vivo Verification of Treatment Source Dwell Times in Brachytherapy of Postoperative Endometrial Carcinoma: A Feasibility Study. J Pers Med 2022; 12:jpm12060911. [PMID: 35743696 PMCID: PMC9224704 DOI: 10.3390/jpm12060911] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Revised: 05/24/2022] [Accepted: 05/28/2022] [Indexed: 11/17/2022] Open
Abstract
(1) Background: In brachytherapy, there are still many manual procedures that can cause adverse events which can be detected with in vivo dosimetry systems. Plastic scintillator dosimeters (PSD) have interesting properties to achieve this objective such as real-time reading, linearity, repeatability, and small size to fit inside brachytherapy catheters. The purpose of this study was to evaluate the performance of a PSD in postoperative endometrial brachytherapy in terms of source dwell time accuracy. (2) Methods: Measurements were carried out in a PMMA phantom to characterise the PSD. Patient measurements in 121 dwell positions were analysed to obtain the differences between planned and measured dwell times. (3) Results: The repeatability test showed a relative standard deviation below 1% for the measured dwell times. The relative standard deviation of the PSD sensitivity with accumulated absorbed dose was lower than 1.2%. The equipment operated linearly in total counts with respect to absorbed dose and also in count rate versus absorbed dose rate. The mean (standard deviation) of the absolute differences between planned and measured dwell times in patient treatments was 0.0 (0.2) seconds. (4) Conclusions: The PSD system is useful as a quality assurance tool for brachytherapy treatments.
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Dürrbeck C, Gulde S, Abu-Hossin N, Fietkau R, Strnad V, Bert C. Influence and compensation of patient motion in electromagnetic tracking based quality assurance in interstitial brachytherapy of the breast. Med Phys 2022; 49:2652-2662. [PMID: 35143053 DOI: 10.1002/mp.15517] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Revised: 12/21/2021] [Accepted: 01/21/2022] [Indexed: 11/08/2022] Open
Abstract
PURPOSE Electromagnetic tracking (EMT) is a versatile and viable technique for various quality assurance (QA) tasks in interstitial brachytherapy (iBT). As the duration of EMT measurements in iBT is on the order of minutes, they can be strongly affected by patient motion, especially breathing, which gives rise to motion artefacts. Since the centrepiece of EMT related QA in iBT is to assess the geometry of the iBT implant or applicator, the absence of adequate motion compensation techniques could impede the use of EMT for QA purposes. A common way to compensate for this is to reference the data to either external or internal reference sensors (ERS, IRS) which are fixated on the patient's body or inside the applicator and therefore move with the patient. The purpose of the presented study is to provide a quantitative and in-depth analysis on the use of reference sensors for motion compensation. METHODS First, the need for adequate motion compensation is identified both qualitatively and quantitatively using a phantom subjected to simulated breathing motion. An evaluation routine is developed to assess the influence of motion compensation using reference sensors on the acquired EMT data. The evaluation metric is based on the observed displacement of the EMT sensor from its mean position while dwelling at a dwell position (DP) for a dwell time of 1 s. After that the routine is applied to a cohort of 54 breast cancer patients treated with iBT and the quality of an ERS based compensation approach is assessed. In a subgroup of four patients, an IRS is inserted into the iBT implant and IRS based compensation is compared to the ERS based approach. Moreover, a correlation analysis of the ERS and IRS approach is performed, also including respiratory signals derived from the trajectories of the different reference sensors. RESULTS It was found that motion compensation with ERS effectively reduced the mean sensor displacement per DP to median values as low as 0.11 mm in both phantom and patient measurements, which is below the precision of the EMT system (0.48 mm). Compensation using the IRS yielded comparable results and was as good as compensation with ERS. The results obtained from both approaches showed a strong correlation. Also the respiratory signals calculated from the different reference sensors were well correlated in most cases. CONCLUSION These results indicate that motion compensation with ERS can effectively remove motion artefacts in EMT data. While compensation with an IRS leads to comparable results, the IRS occupies one catheter whose geometry hence cannot be assessed. The use of ERS has proven to be both effective and practical in clinical routine. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Christopher Dürrbeck
- Department of Radiation Oncology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany.,Comprehensive Cancer Center Erlangen-EMN (CCC ER-EMN), Erlangen, Germany
| | - Sarah Gulde
- Department of Radiation Oncology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany.,Comprehensive Cancer Center Erlangen-EMN (CCC ER-EMN), Erlangen, Germany
| | - Nadin Abu-Hossin
- Department of Radiation Oncology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany.,Comprehensive Cancer Center Erlangen-EMN (CCC ER-EMN), Erlangen, Germany
| | - Rainer Fietkau
- Department of Radiation Oncology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany.,Comprehensive Cancer Center Erlangen-EMN (CCC ER-EMN), Erlangen, Germany
| | - Vratislav Strnad
- Department of Radiation Oncology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany.,Comprehensive Cancer Center Erlangen-EMN (CCC ER-EMN), Erlangen, Germany
| | - Christoph Bert
- Department of Radiation Oncology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany.,Comprehensive Cancer Center Erlangen-EMN (CCC ER-EMN), Erlangen, Germany
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11
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Jørgensen EB, Buus S, Bentzen L, Hokland SB, Rylander S, Kertzscher G, Beddar S, Tanderup K, Johansen JG. 3D dose reconstruction based on in vivo dosimetry for determining the dosimetric impact of geometric variations in high-dose-rate prostate brachytherapy. Radiother Oncol 2022; 171:62-68. [PMID: 35033604 DOI: 10.1016/j.radonc.2022.01.006] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Revised: 12/30/2021] [Accepted: 01/04/2022] [Indexed: 11/16/2022]
Abstract
INTRODUCTION In vivo dosimetry (IVD) can be used for source tracking (ST), i.e., estimating source positions, during brachytherapy. The aim of this study was to exploit IVD-based ST to perform 3D dose reconstruction for high-dose-rate prostate brachytherapy and to evaluate the robustness of the treatments against observed geometric variations. MATERIALS AND METHODS Twenty-three fractions of high-dose-rate prostate brachytherapy were analysed. The treatment planning was based on MRI. Time-resolved IVD was performed using a fibre-coupled scintillator. ST was retrospectively performed using the IVD measurements. The ST identified 2D positional shifts of each treatment catheter and thereby inferred updated source positions. For each fraction, the dose was recalculated based on the source-tracked catheter positions and compared with the original plan dose using differences in dose volume histogram indices. RESULTS Of 352 treatment catheters, 344 had shifts of less than 5 mm. Shifts between 5 and 10 mm were observed for 3 catheters, and shifts greater than 10 mm for 2 catheters. The ST failed for 3 catheters. The maximum relative difference in clinical target volume (prostate + 3 mm isotropic margin) D90% was 5%. In one fraction, the bladder D2cm3 dose increased by 18% (1.4Gy) due to a single source position being inside the bladder rather than nearby as planned. The max increase in urethra dose was 1.5Gy (15%). CONCLUSION IVD-based 3D dose reconstruction for high-dose-rate prostate brachytherapy is feasible. The dosimetric impact of the observed catheter shifts was limited. Dose reconstruction can therefore aid in determining the dosimetric impact of geometric variations and errors in brachytherapy.
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Affiliation(s)
- Erik B Jørgensen
- Department of Clinical Medicine, Aarhus University, Aarhus, Denmark.
| | - Simon Buus
- Department of Oncology, Aarhus University Hospital, Aarhus, Denmark
| | - Lise Bentzen
- Department of Clinical Medicine, Aarhus University, Aarhus, Denmark; Department of Oncology, Aarhus University Hospital, Aarhus, Denmark
| | | | - Susanne Rylander
- Department of Oncology, Aarhus University Hospital, Aarhus, Denmark
| | | | - Sam Beddar
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas, United States
| | - Kari Tanderup
- Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Jacob G Johansen
- Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
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12
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Fonseca GP, van Wagenberg T, Voncken R, Podesta M, van Beveren C, van Limbergen E, Lutgens L, Vanneste B, Berbee M, Reniers B, Verhaegen F. Brachytherapy treatment verification using gamma radiation from the internal treatment source combined with an imaging panel-a phantom study. Phys Med Biol 2021; 66. [PMID: 33831856 DOI: 10.1088/1361-6560/abf605] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2021] [Accepted: 04/08/2021] [Indexed: 12/15/2022]
Abstract
Brachytherapy has an excellent clinical outcome for different treatment sites. However,in vivotreatment verification is not performed in the majority of hospitals due to the lack of proper monitoring systems. This study investigates the use of an imaging panel (IP) and the photons emitted by a high dose rate (HDR)192Ir source to track source motion and obtain some information related to the patient anatomy. The feasibility of this approach was studied by monitoring the treatment delivery to a 3D printed phantom that mimicks a prostate patient. A 3D printed phantom was designed with a template for needle insertion, a cavity ('rectum') to insert an ultrasound probe, and lateral cavities used to place tissue-equivalent materials. CT images were acquired to create HDR192Ir treatment plans with a range of dwell times, interdwell distances and needle arrangements. Treatment delivery was verified with an IP placed at several positions around the phantom using radiopaque markers on the outer surface to register acquired IP images with the planning CT. All dwell positions were identified using acquisition times ≤0.11 s (frame rates ≥ 9 fps). Interdwell distances and dwell positions (in relation to the IP) were verified with accuracy better than 0.1 cm. Radiopaque markers were visible in the acquired images and could be used for registration with CT images. Uncertainties for image registration (IP and planning CT) between 0.1 and 0.4 cm. The IP is sensitive to tissue-mimicking insert composition and showed phantom boundaries that could be used to improve treatment verification. The IP provided sufficient time and spatial resolution for real-time source tracking and allows for the registration of the planning CT and IP images. The results obtained in this study indicate that several treatment errors could be detected including swapped catheters, incorrect dwell times and dwell positions.
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Affiliation(s)
- G P Fonseca
- Department of Radiation Oncology (MAASTRO), GROW School for Oncology and Developmental Biology, Maastricht University Medical Centre+, Doctor Tanslaan 12, 6229 ET Maastricht, The Netherlands
| | - T van Wagenberg
- Department of Radiation Oncology (MAASTRO), GROW School for Oncology and Developmental Biology, Maastricht University Medical Centre+, Doctor Tanslaan 12, 6229 ET Maastricht, The Netherlands
| | - R Voncken
- Department of Radiation Oncology (MAASTRO), GROW School for Oncology and Developmental Biology, Maastricht University Medical Centre+, Doctor Tanslaan 12, 6229 ET Maastricht, The Netherlands
| | - M Podesta
- Department of Radiation Oncology (MAASTRO), GROW School for Oncology and Developmental Biology, Maastricht University Medical Centre+, Doctor Tanslaan 12, 6229 ET Maastricht, The Netherlands
| | - C van Beveren
- Department of Radiation Oncology (MAASTRO), GROW School for Oncology and Developmental Biology, Maastricht University Medical Centre+, Doctor Tanslaan 12, 6229 ET Maastricht, The Netherlands
| | - E van Limbergen
- Department of Radiation Oncology (MAASTRO), GROW School for Oncology and Developmental Biology, Maastricht University Medical Centre+, Doctor Tanslaan 12, 6229 ET Maastricht, The Netherlands
| | - L Lutgens
- Department of Radiation Oncology (MAASTRO), GROW School for Oncology and Developmental Biology, Maastricht University Medical Centre+, Doctor Tanslaan 12, 6229 ET Maastricht, The Netherlands
| | - B Vanneste
- Department of Radiation Oncology (MAASTRO), GROW School for Oncology and Developmental Biology, Maastricht University Medical Centre+, Doctor Tanslaan 12, 6229 ET Maastricht, The Netherlands
| | - M Berbee
- Department of Radiation Oncology (MAASTRO), GROW School for Oncology and Developmental Biology, Maastricht University Medical Centre+, Doctor Tanslaan 12, 6229 ET Maastricht, The Netherlands
| | - B Reniers
- Research group NuTeC, Centre for Environmental Sciences, Hasselt University, Diepenbeek, Belgium
| | - F Verhaegen
- Department of Radiation Oncology (MAASTRO), GROW School for Oncology and Developmental Biology, Maastricht University Medical Centre+, Doctor Tanslaan 12, 6229 ET Maastricht, The Netherlands
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13
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Fonseca GP, Johansen JG, Smith RL, Beaulieu L, Beddar S, Kertzscher G, Verhaegen F, Tanderup K. In vivo dosimetry in brachytherapy: Requirements and future directions for research, development, and clinical practice. PHYSICS & IMAGING IN RADIATION ONCOLOGY 2020; 16:1-11. [PMID: 33458336 PMCID: PMC7807583 DOI: 10.1016/j.phro.2020.09.002] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Revised: 08/24/2020] [Accepted: 09/17/2020] [Indexed: 12/19/2022]
Abstract
Brachytherapy can deliver high doses to the target while sparing healthy tissues due to its steep dose gradient leading to excellent clinical outcome. Treatment accuracy depends on several manual steps making brachytherapy susceptible to operational mistakes. Currently, treatment delivery verification is not routinely available and has led, in some cases, to systematic errors going unnoticed for years. The brachytherapy community promoted developments in in vivo dosimetry (IVD) through research groups and small companies. Although very few of the systems have been used clinically, it was demonstrated that the likelihood of detecting deviations from the treatment plan increases significantly with time-resolved methods. Time–resolved methods could interrupt a treatment avoiding gross errors which is not possible with time-integrated dosimetry. In addition, lower experimental uncertainties can be achieved by using source-tracking instead of direct dose measurements. However, the detector position in relation to the patient anatomy remains a main source of uncertainty. The next steps towards clinical implementation will require clinical trials and systematic reporting of errors and near-misses. It is of utmost importance for each IVD system that its sensitivity to different types of errors is well understood, so that end-users can select the most suitable method for their needs. This report aims to formulate requirements for the stakeholders (clinics, vendors, and researchers) to facilitate increased clinical use of IVD in brachytherapy. The report focuses on high dose-rate IVD in brachytherapy providing an overview and outlining the need for further development and research.
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Affiliation(s)
- Gabriel P Fonseca
- Department of Radiation Oncology (Maastro), GROW School for Oncology, Maastricht University Medical Centre+, Maastricht, Doctor Tanslaan 12, 6229 ET Maastricht, the Netherlands
| | - Jacob G Johansen
- Department of Oncology, Aarhus University Hospital, Palle Juul-Jensens Boulevard 99, DK-8200 Aarhus, Denmark
| | - Ryan L Smith
- Alfred Health Radiation Oncology, Alfred Health, 55 Commercial Rd, Melbourne, VIC 3004, Australia
| | - Luc Beaulieu
- Department of Physics, Engineering Physics & Optics and Cancer Research Center, Université Laval, Quebec City, QC, Canada.,Department of Radiation Oncology, Research Center of CHU de Québec, Université Laval, Quebec City, QC, Canada
| | - Sam Beddar
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Blvd., Unit 1420, Houston, TX 77030, United States
| | - Gustavo Kertzscher
- Department of Oncology, Aarhus University Hospital, Palle Juul-Jensens Boulevard 99, DK-8200 Aarhus, Denmark
| | - Frank Verhaegen
- Department of Radiation Oncology (Maastro), GROW School for Oncology, Maastricht University Medical Centre+, Maastricht, Doctor Tanslaan 12, 6229 ET Maastricht, the Netherlands
| | - Kari Tanderup
- Department of Oncology, Aarhus University Hospital, Palle Juul-Jensens Boulevard 99, DK-8200 Aarhus, Denmark
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14
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Woulfe P, Sullivan FJ, Kam W, O’Keeffe S. Optical fiber dosimeter for real-time in-vivo dose monitoring during LDR brachytherapy. BIOMEDICAL OPTICS EXPRESS 2020; 11:4027-4036. [PMID: 33014583 PMCID: PMC7510901 DOI: 10.1364/boe.385610] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Revised: 02/24/2020] [Accepted: 02/26/2020] [Indexed: 05/28/2023]
Abstract
An optical fiber sensor for monitoring low dose radiation is presented. The sensor, based on radiation sensitive scintillation material, terbium doped gadolinium oxysulphide (Gd2O2S:Tb), is embedded in a cavity of 700µm diameter within a 1mm plastic optical fiber. The sensor is compared with the treatment planning system for repeatability, angular dependency, distance and accumulated radiation activity. The sensor demonstrates a high sensitivity of 152 photon counts/Gy with a temporal resolution of 0.1 seconds, with the largest repeatability error of 4.1%, to 0.361mCi of Iodine-125 the radioactive source most commonly used in LDR brachytherapy for treating prostate cancer.
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Affiliation(s)
- P. Woulfe
- Optical Fiber Sensors Research Centre, University of Limerick, Ireland
- Dept. of Radiotherapy Physics, Galway Clinic, Ireland
| | - F. J. Sullivan
- Prostate Cancer Institute, National University of Ireland Galway, Ireland
- Department of Radiotherapy, Galway Clinic, Ireland
| | - W. Kam
- Optical Fiber Sensors Research Centre, University of Limerick, Ireland
| | - S. O’Keeffe
- Optical Fiber Sensors Research Centre, University of Limerick, Ireland
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15
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First experience of 192Ir source stuck event during high-dose-rate brachytherapy in Japan. J Contemp Brachytherapy 2020; 12:53-60. [PMID: 32190071 PMCID: PMC7073345 DOI: 10.5114/jcb.2020.92401] [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: 08/15/2019] [Accepted: 12/09/2019] [Indexed: 11/17/2022] Open
Abstract
Purpose To share the experience of an iridium-192 (192Ir) source stuck event during high-dose-rate (HDR) brachytherapy for cervical cancer. Material and methods In 2014, we experienced the first source stuck event in Japan when treating cervical cancer with HDR brachytherapy. The cause of the event was a loose screw in the treatment device that interfered with the gear reeling the source. This event had minimal clinical effects on the patient and staff; however, after the event, we created a normal treatment process and an emergency process. In the emergency processes, each staff member is given an appropriate role. The dose rate distribution calculated by the new Monte Carlo simulation system was used as a reference to create the process. Results According to the calculated dose rate distribution, the dose rates inside the maze, near the treatment room door, and near the console room were ≅ 10-2 [cGy · h-1], 10-3 [cGy · h-1], and << 10-3 [cGy · h-1], respectively. Based on these findings, in the emergency process, the recorder was evacuated to the console room, and the rescuer waited inside the maze until the radiation source was recovered. This emergency response manual is currently a critical workflow once a year with vendors. Conclusions We reported our experience of the source stuck event. Details of the event and proposed emergency process will be helpful in managing a patient safety program for other HDR brachytherapy users.
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16
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Masitho S, Kallis K, Strnad V, Fietkau R, Bert C. Error detection using an electromagnetic tracking system in multi-catheter breast interstitial brachytherapy. ACTA ACUST UNITED AC 2019; 64:205018. [DOI: 10.1088/1361-6560/ab4336] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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17
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Marant-Micallef C, Shield KD, Vignat J, Cléro E, Kesminiene A, Hill C, Rogel A, Vacquier B, Bray F, Laurier D, Soerjomataram I. The risk of cancer attributable to diagnostic medical radiation: Estimation for France in 2015. Int J Cancer 2019; 144:2954-2963. [PMID: 30537057 DOI: 10.1002/ijc.32048] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2018] [Revised: 11/26/2018] [Accepted: 11/27/2018] [Indexed: 01/06/2023]
Abstract
Although medical ionizing radiation (IR) has clear clinical benefits, it is an established carcinogen. Our study estimates the number of new cancer cases in France in 2015 attributable to IR exposure from medical procedures. Exposures from external (X-rays, CT scans, interventional radiology) and internal (nuclear medicine) sources were considered. We used 2007 national frequencies of diagnostic examinations by sex and age to estimate the lifetime organ dose exposure adjusted for changes in the use of such procedures over time. The Biological Effects of Ionizing Radiation VII risk models were used to estimate the corresponding excess cancer risk, assuming an average latency period of 10 years. Additionally, we used cancer incidence data from the French Cancer Registries Network. Of the 346,000 estimated new cancer cases in adults in France in 2015, 2300 cases (940 among men and 1360 among women) were attributable to diagnostic IR, representing 0.7% of all new cancer cases (0.5% for men and 0.9% for women). The leading cancers attributable to medical IR were female breast (n = 560 cases), lung (n = 500 cases) and colon (n = 290 cases) cancers. Compared to other risk factors, the contribution of medical IR to the cancer burden is small, and the benefits largely outweigh its harms. However, some of these IR-associated cancer cases may be preventable through dose optimization of and enhanced justification for diagnostic examinations.
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Affiliation(s)
- Claire Marant-Micallef
- Section of Cancer Surveillance, International Agency for Research on Cancer, Lyon, France
| | - Kevin D Shield
- Section of Cancer Surveillance, International Agency for Research on Cancer, Lyon, France
| | - Jérôme Vignat
- Section of Cancer Surveillance, International Agency for Research on Cancer, Lyon, France
| | - Enora Cléro
- Institute for Radiological Protection and Nuclear Safety, Fontenay-aux-Roses, France
| | - Ausrele Kesminiene
- Senior Visiting Scientist, Section of Environment and Radiation, International Agency for Research on Cancer, Lyon, France
| | | | - Agnès Rogel
- Santé Publique France, Saint-Maurice, France
| | | | - Freddie Bray
- Section of Cancer Surveillance, International Agency for Research on Cancer, Lyon, France
| | - Dominique Laurier
- Institute for Radiological Protection and Nuclear Safety, Fontenay-aux-Roses, France
| | - Isabelle Soerjomataram
- Section of Cancer Surveillance, International Agency for Research on Cancer, Lyon, France
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18
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Fonseca GP, Podesta M, Bellezzo M, Van den Bosch MR, Lutgens L, Vanneste BGL, Voncken R, Van Limbergen EJ, Reniers B, Verhaegen F. Online pretreatment verification of high-dose rate brachytherapy using an imaging panel. Phys Med Biol 2018; 62:5440-5461. [PMID: 28609297 DOI: 10.1088/1361-6560/aa7028] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Brachytherapy is employed to treat a wide variety of cancers. However, an accurate treatment verification method is currently not available. This study describes a pre-treatment verification system that uses an imaging panel (IP) to verify important aspects of the treatment plan. A detailed modelling of the IP was only possible with an extensive calibration performed using a robotic arm. Irradiations were performed with a high dose rate (HDR) 192Ir source within a water phantom. An empirical fit was applied to measure the distance between the source and the detector so 3D Cartesian coordinates of the dwell positions can be obtained using a single panel. The IP acquires 7.14 fps to verify the dwell times, dwell positions and air kerma strength (Sk). A gynecological applicator was used to create a treatment plan that was registered with a CT image of the water phantom used during the experiments for verification purposes. Errors (shifts, exchanged connections and wrong dwell times) were simulated to verify the proposed verification system. Cartesian source positions (panel measurement plane) have a standard deviation of about 0.02 cm. The measured distance between the source and the panel (z-coordinate) have a standard deviation up to 0.16 cm and maximum absolute error of ≈0.6 cm if the signal is close to sensitive limit of the panel. The average response of the panel is very linear with Sk. Therefore, Sk measurements can be performed with relatively small errors. The measured dwell times show a maximum error of 0.2 s which is consistent with the acquisition rate of the panel. All simulated errors were clearly identified by the proposed system. The use of IPs is not common in brachytherapy, however, it provides considerable advantages. It was demonstrated that the IP can accurately measure Sk, dwell times and dwell positions.
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Affiliation(s)
- Gabriel P Fonseca
- Department of Radiation Oncology (MAASTRO), GROW-School for Oncology and Developmental Biology, Maastricht University Medical Center, Dr. Tanslaan 12, Maastricht 6229 ET, Netherlands
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Treatment plan dosimetric impact after catheter stretch during multi-catheter interstitial breast brachytherapy. J Contemp Brachytherapy 2017; 9:418-423. [PMID: 29204162 PMCID: PMC5705834 DOI: 10.5114/jcb.2017.70987] [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: 05/18/2017] [Accepted: 07/27/2017] [Indexed: 11/24/2022] Open
Abstract
Purpose Nylon 6/6 interstitial brachytherapy catheters may stretch when exposed to moisture, mechanical tension, and body temperature. The purpose of this study is to evaluate the magnitude of catheter stretch during a course of multi-catheter interstitial breast brachytherapy for nylon 6/6 treatment catheters, and to assess the impact this has on treatment plan dosimetry. Material and methods Catheters were exposed to water at 37°C for six days and the internal catheter length change (ΔL_W) was measured daily. Additionally, the measured internal catheter length change (ΔL_P), performed prior to each treatment fraction, for seven interstitial breast brachytherapy patients (total of 76 catheters) were retrospectively analyzed. The maximum length change seen in ΔL_P and ΔL_W were introduced as a source positional error to retrospective treatment plans, and treatment plan dosimetry was analyzed. Results ΔL_W and ΔL_P were on average +4.0% and +1.6% of the catheter lengths in water or tissue after 48 hours. Weak correlation was seen between the average ΔL_P per catheter and both the catheter length within tissue (ρ = 0.36, p = 0.0007), and the mid-catheter depth in tissue (ρ = 0.42, p < 0.0001). The D90CTV decreased 1.5% (p < 0.05) and 8.2% (p < 0.05) when the ΔL_P and ΔL_W were introduced to the initial plans. Conclusions Nylon 6/6 catheters stretch during a course of multi-catheter interstitial breast brachytherapy treatment. The observed stretch may affect treatment plan dosimetry, if the catheter internal length is only measured immediately after the insertion. Additional catheter length checks are recommended to verify the actual catheter internal length during the treatment.
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Ramachandran P. New era of electronic brachytherapy. World J Radiol 2017; 9:148-154. [PMID: 28529679 PMCID: PMC5415885 DOI: 10.4329/wjr.v9.i4.148] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/30/2016] [Revised: 12/05/2016] [Accepted: 01/18/2017] [Indexed: 02/06/2023] Open
Abstract
Traditional brachytherapy refers to the placement of radioactive sources on or inside the cancer tissues. Based on the type of sources, brachytherapy can be classified as radionuclide and electronic brachytherapy. Electronic brachytherapy uses miniaturized X-ray sources instead of radionuclides to deliver high doses of radiation. The advantages of electronic brachytherapy include low dose to organs at risk, reduced dose to treating staff, no leakage radiation in off state, less shielding, and no radioactive waste. Most of these systems operate between 50 and 100 kVp and are widely used in the treatment of skin cancer. Intrabeam, Xoft and Papillon systems are also used in the treatment of intra-operative radiotherapy to breast in addition to other treatment sites. The rapid fall-off in the dose due to its low energy is a highly desirable property in brachytherapy and results in a reduced dose to the surrounding normal tissues compared to the Ir-192 source. The Xoft Axxent brachytherapy system uses a 2.25 mm miniaturized X-ray tube and the source almost mimics the high dose rate Ir-192 source in terms of dose rate and it is the only electronic brachytherapy system specifically used in the treatment of cervical cancers. One of the limiting factors that impede the use of electronic brachytherapy for interstitial application is the source dimension. However, it is highly anticipated that the design of miniaturized X-ray tube closer to the dimension of an Ir-192 wire is not too far away, and the new era of electronic brachytherapy has just begun.
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21
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Electromagnetic tracking for treatment verification in interstitial brachytherapy. J Contemp Brachytherapy 2016; 8:448-453. [PMID: 27895688 PMCID: PMC5116452 DOI: 10.5114/jcb.2016.63356] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2016] [Accepted: 10/04/2016] [Indexed: 11/29/2022] Open
Abstract
Electromagnetic tracking (EMT) is used in several medical fields to determine the position and orientation of dedicated sensors, e.g., attached to surgical tools. Recently, EMT has been introduced to brachytherapy for implant reconstruction and error detection. The manuscript briefly summarizes the main issues of EMT and error detection in brachytherapy. The potential and complementarity of EMT as treatment verification technology will be discussed in relation to in vivo dosimetry and imaging.
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Moloney F, Fama D, Twomey M, O’Leary R, Houlihane C, Murphy KP, O’Neill SB, O’Connor OJ, Breen D, Maher MM. Cumulative radiation exposure from diagnostic imaging in intensive care unit patients. World J Radiol 2016; 8:419-427. [PMID: 27158429 PMCID: PMC4840200 DOI: 10.4329/wjr.v8.i4.419] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/25/2015] [Revised: 12/03/2015] [Accepted: 01/31/2016] [Indexed: 02/06/2023] Open
Abstract
AIM: To quantify cumulative effective dose of intensive care unit (ICU) patients attributable to diagnostic imaging.
METHODS: This was a prospective, interdisciplinary study conducted in the ICU of a large tertiary referral and level 1 trauma center. Demographic and clinical data including age, gender, date of ICU admission, primary reason for ICU admission, APACHE II score, length of stay, number of days intubated, date of death or discharge, and re-admission data was collected on all patients admitted over a 1-year period. The overall radiation exposure was quantified by the cumulative effective radiation dose (CED) in millisieverts (mSv) and calculated using reference effective doses published by the United Kingdom National Radiation Protection Board. Pediatric patients were selected for subgroup-analysis.
RESULTS: A total of 2737 studies were performed in 421 patients. The total CED was 1704 mSv with a median CED of 1.5 mSv (IQR 0.04-6.6 mSv). Total CED in pediatric patients was 74.6 mSv with a median CED of 0.07 mSv (IQR 0.01-4.7 mSv). Chest radiography was the most commonly performed examination accounting for 83% of all studies but only 2.7% of total CED. Computed tomography (CT) accounted for 16% of all studies performed and contributed 97% of total CED. Trauma patients received a statistically significant higher dose [median CED 7.7 mSv (IQR 3.5-13.8 mSv)] than medical [median CED 1.4 mSv (IQR 0.05-5.4 mSv)] and surgical [median CED 1.6 mSv (IQR 0.04-7.5 mSv)] patients. Length of stay in ICU [OR = 1.12 (95%CI: 1.079-1.157)] was identified as an independent predictor of receiving a CED greater than 15 mSv.
CONCLUSION: Trauma patients and patients with extended ICU admission times are at increased risk of higher CEDs. CED should be minimized where feasible, especially in young patients.
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Smith RL, Haworth A, Panettieri V, Millar JL, Franich RD. A method for verification of treatment delivery in HDR prostate brachytherapy using a flat panel detector for both imaging and source tracking. Med Phys 2016; 43:2435. [DOI: 10.1118/1.4946820] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Abstract
Dosimetric audit is required for the improvement of patient safety in radiotherapy and to aid optimization of treatment. The reassurance that treatment is being delivered in line with accepted standards, that delivered doses are as prescribed and that quality improvement is enabled is as essential for brachytherapy as it is for the more commonly audited external beam radiotherapy. Dose measurement in brachytherapy is challenging owing to steep dose gradients and small scales, especially in the context of an audit. Several different approaches have been taken for audit measurement to date: thimble and well-type ionization chambers, thermoluminescent detectors, optically stimulated luminescence detectors, radiochromic film and alanine. In this work, we review all of the dosimetric brachytherapy audits that have been conducted in recent years, look at current audits in progress and propose required directions for brachytherapy dosimetric audit in the future. The concern over accurate source strength measurement may be essentially resolved with modern equipment and calibration methods, but brachytherapy is a rapidly developing field and dosimetric audit must keep pace.
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Affiliation(s)
- A L Palmer
- Department of Physics, Faculty of Engineering and Physical Science, University of Surrey, UK
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ACPSEM brachytherapy working group recommendations for quality assurance in brachytherapy. AUSTRALASIAN PHYSICAL & ENGINEERING SCIENCES IN MEDICINE 2013; 36:387-96. [DOI: 10.1007/s13246-013-0228-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Lawler PR, Afilalo J, Eisenberg MJ, Pilote L. Comparison of cancer risk associated with low-dose ionizing radiation from cardiac imaging and therapeutic procedures after acute myocardial infarction in women versus men. Am J Cardiol 2013; 112:1545-50. [PMID: 23972348 DOI: 10.1016/j.amjcard.2013.07.009] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/12/2013] [Revised: 07/12/2013] [Accepted: 07/12/2013] [Indexed: 10/26/2022]
Abstract
Patients with cardiovascular disease are increasingly exposed to low-dose ionizing radiation (LDIR) from diagnostic and therapeutic procedures. Previous studies have suggested that the malignancy risk associated with LDIR may be greatest in women and in young patients. We sought to compare the effect of LDIR on incident cancer across gender and age strata in a population-based cohort of patients with myocardial infarction (MI). All initially cancer-free patients with MI from 1996 to 2006 were identified in a province-wide administrative database. Procedure-specific LDIR dose estimates were used to generate a cumulative cardiac LDIR exposure variable. Time-dependent multivariate Cox regression was used to determine the relation between cardiac LDIR and incident cancer. A time-lag covariate of 3 years was used wherein a de novo cancer could only be attributed to LDIR incurred at least 3 years earlier. The effect of age and gender on LDIR-associated risk of cancer was evaluated with stratified models and the addition of interaction terms. The study cohort consisted of 56,606 men and 26,255 women. For each millisievert of cardiac LDIR, women were more likely to develop a cancer (hazard ratio 1.005, 95% confidence interval 1.002 to 1.008) than men (hazard ratio 1.002, 95% confidence interval 1.001 to 1.004) after adjusting for age, noncardiac LDIR, and covariates (p for interaction = 0.014). Contrarily, over the range studied (predominantly patients aged >50 years), age was not a determinant of LDIR-associated risk of cancer. In conclusion, women exposed to LDIR from cardiac imaging and therapeutic procedures after MI are at a greater risk of incident cancer compared with men after similar exposure. The extrapolated absolute risk from LDIR exposure would nonetheless be expected to be low.
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Smith RL, Taylor ML, McDermott LN, Haworth A, Millar JL, Franich RD. Source position verification and dosimetry in HDR brachytherapy using an EPID. Med Phys 2013; 40:111706. [DOI: 10.1118/1.4823758] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
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Martineau-Beaulieu D, Lanthier L. Low-dose ionising radiation from medical imaging in patients hospitalised in Internal Medicine. Intern Med J 2013; 42:547-53. [PMID: 22152026 DOI: 10.1111/j.1445-5994.2011.02640.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
BACKGROUND Medical imaging is responsible for increasing exposure to low-dose ionising radiation in the general population. The extent of exposure in specific patient populations remains to be determined. AIM We sought to determine the level of exposure in patients hospitalised in General Internal Medicine. METHODS In this retrospective cohort study, we searched the Centre Informatisé de Recherche Évaluative en Services et Soins de Santé database for adult patients hospitalised in General Internal Medicine from 1 January 2008 to 31 December 2008. We collected data on demographics, co-morbidities, and radiological and nuclear imaging. We used data from the literature to calculate an estimated annual effective dose for each patient and searched for factors associated with higher exposure. RESULTS One thousand one hundred eighty-seven (1187) patients were hospitalised at least once during the study period. The median age was 69 years (interquartile range 56-81) and 636 (53.6%) were men. The median annual effective dose of the whole cohort was 8.7 mSv/year. Patients aged between 55 and 80 years were exposed to a higher median effective dose compared with their younger and older counterparts (P < 0.001). Patients with cardiac, pulmonary, peripheral arterial and neoplastic disease were at higher risk of exposure to high and very high annual effective dose (P < 0.01). Patients with longer hospitalisations were at higher risk of exposure to high and very high annual effective dose (P < 0.01). CONCLUSION Patients hospitalised on a General Internal Medicine ward are exposed to three times more ionising radiation than the general population.
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Affiliation(s)
- D Martineau-Beaulieu
- Department of Medicine, Internal Medicine Division, Centre Hospitalier Universitaire de Sherbrooke (CHUS), Sherbrooke, Quebec, Canada
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Palmer A, Bradley D, Nisbet A. Physics-aspects of dose accuracy in high dose rate (HDR) brachytherapy: source dosimetry, treatment planning, equipment performance and in vivo verification techniques. J Contemp Brachytherapy 2012; 4:81-91. [PMID: 23349649 PMCID: PMC3552629 DOI: 10.5114/jcb.2012.29364] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2012] [Revised: 04/14/2012] [Accepted: 05/05/2012] [Indexed: 11/17/2022] Open
Abstract
This study provides a review of recent publications on the physics-aspects of dosimetric accuracy in high dose rate (HDR) brachytherapy. The discussion of accuracy is primarily concerned with uncertainties, but methods to improve dose conformation to the prescribed intended dose distribution are also noted. The main aim of the paper is to review current practical techniques and methods employed for HDR brachytherapy dosimetry. This includes work on the determination of dose rate fields around brachytherapy sources, the capability of treatment planning systems, the performance of treatment units and methods to verify dose delivery. This work highlights the determinants of accuracy in HDR dosimetry and treatment delivery and presents a selection of papers, focusing on articles from the last five years, to reflect active areas of research and development. Apart from Monte Carlo modelling of source dosimetry, there is no clear consensus on the optimum techniques to be used to assure dosimetric accuracy through all the processes involved in HDR brachytherapy treatment. With the exception of the ESTRO mailed dosimetry service, there is little dosimetric audit activity reported in the literature, when compared with external beam radiotherapy verification.
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Affiliation(s)
- Antony Palmer
- Department of Physics, Faculty of Engineering and Physical Science, University of Surrey, United Kingdom
- Medical Physics Department, Queen Alexandra Hospital, Portsmouth Hospitals NHS Trust, Portsmouth, United Kingdom
| | - David Bradley
- Department of Physics, Faculty of Engineering and Physical Science, University of Surrey, United Kingdom
| | - Andrew Nisbet
- Department of Physics, Faculty of Engineering and Physical Science, University of Surrey, United Kingdom
- Medical Physics Department, Royal Surrey County Hospital NHS Foundation Trust, Guildford, United Kingdom
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Einstein AJ, Knuuti J. Cardiac imaging: does radiation matter? Eur Heart J 2012; 33:573-8. [PMID: 21828062 PMCID: PMC3291500 DOI: 10.1093/eurheartj/ehr281] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/11/2011] [Revised: 06/14/2011] [Accepted: 07/14/2011] [Indexed: 12/13/2022] Open
Abstract
The use of ionizing radiation in cardiovascular imaging has generated considerable discussion. Radiation should not be considered in isolation, but rather in the context of a careful examination of the benefits, risks, and costs of cardiovascular imaging. Such consideration requires an understanding of some fundamental aspects of the biology, physics, epidemiology, and terminology germane to radiation, as well as principles of radiological protection. This paper offers a concise, contemporary perspective on these areas by addressing pertinent questions relating to radiation and its application to cardiac imaging.
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Affiliation(s)
- Andrew J Einstein
- Cardiology Division, Department of Medicine, Columbia University Medical Center and New York-Presbyterian Hospital, New York, NY, USA.
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Cunningham J, Coffey M, Knöös T, Holmberg O. Radiation Oncology Safety Information System (ROSIS)--profiles of participants and the first 1074 incident reports. Radiother Oncol 2010; 97:601-7. [PMID: 21087801 DOI: 10.1016/j.radonc.2010.10.023] [Citation(s) in RCA: 74] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2009] [Revised: 10/19/2010] [Accepted: 10/23/2010] [Indexed: 11/17/2022]
Abstract
BACKGROUND AND PURPOSE The Radiation Oncology Safety Information System (ROSIS) was established in 2001. The aim of ROSIS is to collate and share information on incidents and near-incidents in radiotherapy, and to learn from these incidents in the context of departmental infrastructure and procedures. MATERIALS AND METHODS A voluntary web-based cross-organisational and international reporting and learning system was developed (cf. the www.rosis.info website). Data is collected via online Department Description and Incident Report Forms. A total of 101 departments, and 1074 incident reports are reviewed. RESULTS The ROSIS departments represent about 150,000 patients, 343 megavoltage (MV) units, and 114 brachytherapy units. On average, there are 437 patients per MV unit, 281 per radiation oncologist, 387 per physicist and 353 per radiation therapy technologist (RT/RTT). Only 14 departments have a completely networked system of electronic data transfer, while 10 departments have no electronic data transfer. On average seven quality assurance (QA) or quality control (QC) methods are used at each department. A total of 1074 ROSIS reports are analysed; 97.7% relate to external beam radiation treatment and 50% resulted in incorrect irradiation. Many incidents arise during pre-treatment but are not detected until later in the treatment process. Where an incident is not detected prior to treatment, an average of 22% of the prescribed treatment fractions were delivered incorrectly. The most commonly reported detection methods were "found at time of patient treatment" and during "chart-check". CONCLUSION While the majority of the incidents that reported to this international cross-organisational reporting system are of minor dosimetric consequence, they affect on average more than 20% of the patient's treatment fractions. Nonetheless, defence-in-depth is apparent in departments registered with ROSIS. This indicates a need for further evaluation of the effectiveness of quality controls.
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Affiliation(s)
- Joanne Cunningham
- Discipline of Radiation Therapy, School of Medicine, Trinity College, Dublin, Ireland.
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Rumack CM. 2010 ACR Presidential Address: Patient-Focused Radiology: Taking Charge of Radiation Dose. J Am Coll Radiol 2010; 7:837-44. [DOI: 10.1016/j.jacr.2010.07.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2010] [Accepted: 07/01/2010] [Indexed: 11/28/2022]
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A program for the independent verification of brachytherapy planning system calculations. J Contemp Brachytherapy 2010; 2:129-133. [PMID: 27853474 PMCID: PMC5104832 DOI: 10.5114/jcb.2010.16924] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2010] [Accepted: 09/21/2010] [Indexed: 11/17/2022] Open
Abstract
Purpose In this work a spreadsheet based program is presented that to a large extent independently verifies the calculations of individual plans of brachytherapy treatment planning systems for low dose rate, high dose rate and pulsed dose rate techniques. Material and methods The verification program has been developed based on workbooks/spreadsheets. The treatment planning system output text files are automatically loaded into the new program, allowing the use of the source coordinates, the desired calculation point coordinates, and the dwell times of a patient plan. The source strength and the reference dates are entered by the user and then dose points calculations are independently performed. The program shows its results in a comparison of its calculated point dose data with the corresponding TPS outcome. Results Results of 250 clinical cases show agreement with the TPS outcome within a 2% level. Conclusions The program allows the implementation of the recommendations to verify the clinical brachytherapy dosimetry in a simple and accurate way, in only few minutes and with a minimum of user interactions.
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Safety aspects of pulsed dose rate brachytherapy: analysis of errors in 1,300 treatment sessions. Int J Radiat Oncol Biol Phys 2008; 70:953-60. [PMID: 18262105 DOI: 10.1016/j.ijrobp.2007.11.003] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2007] [Revised: 11/01/2007] [Accepted: 11/01/2007] [Indexed: 11/22/2022]
Abstract
PURPOSE To determine the safety of pulsed-dose-rate (PDR) brachytherapy by analyzing errors and technical failures during treatment. METHODS AND MATERIALS More than 1,300 patients underwent treatment with PDR brachytherapy, using five PDR remote afterloaders. Most patients were treated with consecutive pulse schemes, also outside regular office hours. Tumors were located in the breast, esophagus, prostate, bladder, gynecology, anus/rectum, orbit, head/neck, with a miscellaneous group of small numbers, such as the lip, nose, and bile duct. Errors and technical failures were analyzed for 1,300 treatment sessions, for which nearly 20,000 pulses were delivered. For each tumor localization, the number and type of occurring errors were determined, as were which localizations were more error prone than others. RESULTS By routinely using the built-in dummy check source, only 0.2% of all pulses showed an error during the phase of the pulse when the active source was outside the afterloader. Localizations treated using flexible catheters had greater error frequencies than those treated with straight needles or rigid applicators. Disturbed pulse frequencies were in the range of 0.6% for the anus/rectum on a classic version 1 afterloader to 14.9% for orbital tumors using a version 2 afterloader. Exceeding the planned overall treatment time by >10% was observed in only 1% of all treatments. Patients received their dose as originally planned in 98% of all treatments. CONCLUSIONS According to the experience in our institute with 1,300 PDR treatments, we found that PDR is a safe brachytherapy treatment modality, both during and outside of office hours.
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Hujoel P, Hollender L, Bollen AM, Young JD, McGee M, Grosso A. Head-and-neck organ doses from an episode of orthodontic care. Am J Orthod Dentofacial Orthop 2008; 133:210-7. [PMID: 18249287 DOI: 10.1016/j.ajodo.2007.10.026] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2007] [Revised: 09/24/2007] [Accepted: 10/18/2007] [Indexed: 10/22/2022]
Abstract
INTRODUCTION The high prevalence of orthodontic treatment in young people makes the associated radiation to the head and neck of potential public-health significance. In this study, we estimated secular changes (1963-2003) in age-specific organ doses associated with orthodontic care and collective organ doses in the United States in 1999. METHODS A survey of radiographic records at 1 university clinic was combined with published estimates to provide organ-specific radiation doses. Collective organ doses were estimated from the 1999 US Nationwide Evaluation of X-ray Trends and published orthodontic utilization surveys. RESULTS Before 1992, orthodontic care in a university setting was associated with mean doses of 7.0 milligrays (mGy) to the thyroid, 0.8 mGy to the red bone marrow, 2.7 mGy to the brain, 13.2 mGy to the salivary glands, and 5.1 mGy to the bone. After 1992, the doses decreased to 2.8 mGy to the thyroid, 0.3 mGy to the red bone marrow, 0.7 mGy to the brain, 6.2 mGy to the saliva glands, and 2.4 mGy to the bone. Around 1999, the collective doses associated with orthodontic care in the United States in patients less than 19 years of age were 400 Gy to the red bone marrow and 3800 Gy to the thyroid. CONCLUSIONS Orthodontic care, in part due to its high prevalence, potentially contributes significantly to the diagnostic radiation burden in those less than 19 years old in the United States.
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Affiliation(s)
- Philippe Hujoel
- Department of Dental Public Health Sciences and Epidemiology, School of Dentistry, University of Washington, Seattle, WA 98195-7475, USA.
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