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Hunt B, Cutajar D, Petasecca M, Rosenfeld A, Howie A, Bucci J, Poder J. HDR brachytherapy afterloader quality assurance optimization using monolithic silicon strip detectors. Med Phys 2024; 51:4581-4590. [PMID: 38837408 DOI: 10.1002/mp.17240] [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: 03/04/2024] [Revised: 05/22/2024] [Accepted: 05/22/2024] [Indexed: 06/07/2024] Open
Abstract
BACKGROUND There currently exists no widespread high dose-rate (HDR) brachytherapy afterloader quality assurance (QA) tool for simultaneously assessing the afterloader's positional, temporal, transit velocity and air kerma strength accuracy. PURPOSE The purpose of this study was to develop a precise and rigorous technique for performing daily QA of HDR brachytherapy afterloaders, incorporating QA of: dwell position accuracy, dwell time accuracy, transit velocity consistency and relative air kerma strength (AKS) of an Ir-192 source. METHOD A Sharp ProGuide 240 mm catheter (Elekta Brachytherapy, Veenendaal, The Netherlands) was fixed 5 mm above a 256 channel epitaxial diode array 'dose magnifying glass' (DMG256) (Centre for Medical and Radiation Physics, University of Wollongong). Three dwell positions, each of 5.0 s dwell times, were spaced 13.0 mm apart along the array with the Flexitron HDR afterloader (Elekta Brachytherapy, Veenendaal, The Netherlands). The DMG256 was connected to a data acquisition system (DAQ) and a computer via USB2.0 link for live readout and post-processing. The outputted data files were analyzed using a Python script to provide positional and temporal localization of the Ir-192 source by tracking the centroid of the detected response. Measurements were repeated on a weekly basis, for a period of 5 weeks to determine the consistency of the measured parameters over an extended period. RESULTS Using the DMG256 for relative AKS measurements resulted in measured values within 0.6%-3.0% of the expected activity over a 7-week period. The sub-millisecond temporal accuracy of the device allowed for measurements of the transit velocity with an average of (10.88 ± 1.01) cm/s for 13 mm steps. The dwell position localization for 1, 2, 3, 5, and 10 mm steps had an accuracy between 0.1 and 0.3 mm (3σ), with a fixed temporal accuracy of 10 ms. CONCLUSION The DMG256 silicon strip detector allows for clinics to perform rigorous daily QA of HDR afterloader dwell position and dwell time accuracy with greater precision than the current standard methodology using closed circuit television and a stopwatch. Additionally, DMG256 unlocks the ability to perform measurements of transit velocity/time and relative AKS, which are not possible using current standard techniques.
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Affiliation(s)
- Broady Hunt
- Centre for Medical Radiation Physics, University of Wollongong, Wollongong, NSW, Australia
| | - Dean Cutajar
- Centre for Medical Radiation Physics, University of Wollongong, Wollongong, NSW, Australia
| | - Marco Petasecca
- Centre for Medical Radiation Physics, University of Wollongong, Wollongong, NSW, Australia
| | - Anatoly Rosenfeld
- Centre for Medical Radiation Physics, University of Wollongong, Wollongong, NSW, Australia
| | - Andrew Howie
- Department of Radiation Oncology, St George Cancer Care Centre, Kogarah, NSW, Australia
| | - Joseph Bucci
- Department of Radiation Oncology, St George Cancer Care Centre, Kogarah, NSW, Australia
| | - Joel Poder
- Centre for Medical Radiation Physics, University of Wollongong, Wollongong, NSW, Australia
- Department of Radiation Oncology, St George Cancer Care Centre, Kogarah, NSW, Australia
- School of Physics, University of Sydney, Camperdown, NSW, Australia
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2
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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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3
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Bienvenido R, Quiñones LÁ, Pérez J, Castro I, Gutiérrez L, López JDD, Botana J, Iborra MA. Study of dose dependence on density in planar 3D-printed applicators for HDR Ir 192 surface brachytherapy. Brachytherapy 2023; 22:250-259. [PMID: 36456464 DOI: 10.1016/j.brachy.2022.10.011] [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: 03/24/2022] [Revised: 09/29/2022] [Accepted: 10/23/2022] [Indexed: 11/29/2022]
Abstract
PURPOSE This paper describes a method to evaluate the influence of 3D printed plesiotherapy applicators densities in the most clinically relevant dosimetric planes of these brachytherapy treatments. Studied densities range goes from that of water to that of air including the intermediate applicators densities made of acrylonitrile butadiene styrene and polylactic acid, materials used as Fused Deposition Modelling (FDM) filaments. METHODS AND MATERIALS All applicators were manufactured by means of FDM 3D printing and a special empty applicator of ABS walls was designed to be filled with water or air. In each of these applicators, the values of the dose and gamma index at the surface and at the prescription depth were measured in clinical conditions, using EBT films. RESULTS Analysis of results allow us to conclude that the influence of the applicators density on the dose value in the studied materials depends on the distance at which the dose is measured. Thus, at the prescription depth no influence is observed, however this influence becomes noticeable near the surface of the applicators with dose differences of more than 10% for densities close to 0.4 g/cm3. CONCLUSION Therefore, the density of FDM manufactured applicators should be taken into account when calculating surface dose for low density applicators, as variations caused by density can have clinical implications because is the surface dose that is associated with the toxicity of brachytherapy skin treatments.
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Affiliation(s)
- Rafael Bienvenido
- Mechanical Engineering and Industrial Design Department, Escuela Superior de Ingeniería, Universidad de Cádiz, Puerto Real, Cádiz, Spain
| | | | - Joaquín Pérez
- Radiophysics Unit, Hospital Universitario Puerta del Mar, Cádiz, Spain
| | - Ignacio Castro
- Radiophysics Unit, Hospital Universitario Puerta del Mar, Cádiz, Spain
| | - Lucía Gutiérrez
- Radiation Oncology Unit, Hospital Universitario Puerta del Mar, Cádiz, Spain
| | - Juan de Dios López
- Material Science, Metallurgy Engineering and Inorganic Chemistry Department, Escuela Superior de Ingeniería, Universidad de Cádiz, Puerto Real, Cádiz, Spain
| | - Javier Botana
- Material Science, Metallurgy Engineering and Inorganic Chemistry Department, Escuela Superior de Ingeniería, Universidad de Cádiz, Puerto Real, Cádiz, Spain.
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4
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Houlihan OA, Workman G, Hounsell AR, Prise KM, Jain S. In vivo dosimetry in pelvic brachytherapy. Br J Radiol 2022; 95:20220046. [PMID: 35635803 PMCID: PMC10996950 DOI: 10.1259/bjr.20220046] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2022] [Revised: 05/06/2022] [Accepted: 05/11/2022] [Indexed: 11/05/2022] Open
Abstract
ADVANCES IN KNOWLEDGE This paper describes the potential role for in vivo dosimetry in the reduction of uncertainties in pelvic brachytherapy, the pertinent factors for consideration in clinical practice, and the future potential for in vivo dosimetry in the personalisation of brachytherapy.
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Affiliation(s)
- Orla Anne Houlihan
- Department of Clinical Oncology, Northern Ireland Cancer
Centre, Belfast Health and Social Care Trust,
Belfast, UK
- Patrick G. Johnston Centre for Cancer Research, Queen's
University Belfast, Belfast,
UK
| | - Geraldine Workman
- Radiotherapy Physics, Northern Ireland Cancer Centre, Belfast
Health and Social Care Trust,
Belfast, UK
| | - Alan R Hounsell
- Patrick G. Johnston Centre for Cancer Research, Queen's
University Belfast, Belfast,
UK
- Radiotherapy Physics, Northern Ireland Cancer Centre, Belfast
Health and Social Care Trust,
Belfast, UK
| | - Kevin M Prise
- Patrick G. Johnston Centre for Cancer Research, Queen's
University Belfast, Belfast,
UK
| | - Suneil Jain
- Department of Clinical Oncology, Northern Ireland Cancer
Centre, Belfast Health and Social Care Trust,
Belfast, UK
- Patrick G. Johnston Centre for Cancer Research, Queen's
University Belfast, Belfast,
UK
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Okamoto H, Iijima K, Chiba T, Takemori M, Nakayam H, Fujii K, Kon M, Mikasa S, Nakaichi T, Urago Y, Aikawa A, Katsuta S, Nakamura S, Igaki H. Technical note: Analysis of brachytherapy source movement by high‐speed camera. Med Phys 2022; 49:4804-4811. [DOI: 10.1002/mp.15601] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Revised: 03/07/2022] [Accepted: 03/07/2022] [Indexed: 11/11/2022] Open
Affiliation(s)
- Hiroyuki Okamoto
- Radiation Safety and Quality Assurance Division National Cancer Center Hospital Tokyo 104‐0045 Japan
| | - Kotaro Iijima
- Radiation Safety and Quality Assurance Division National Cancer Center Hospital Tokyo 104‐0045 Japan
| | - Takahito Chiba
- Radiation Safety and Quality Assurance Division National Cancer Center Hospital Tokyo 104‐0045 Japan
| | - Mihiro Takemori
- Radiation Safety and Quality Assurance Division National Cancer Center Hospital Tokyo 104‐0045 Japan
| | - Hiroki Nakayam
- Radiation Safety and Quality Assurance Division National Cancer Center Hospital Tokyo 104‐0045 Japan
| | - Kyohei Fujii
- Radiation Safety and Quality Assurance Division National Cancer Center Hospital Tokyo 104‐0045 Japan
| | - Mitsuhiro Kon
- Department of Radiological Technology National Cancer Center Hospital Tokyo 104‐0045 Japan
| | - Shohei Mikasa
- Radiation Safety and Quality Assurance Division National Cancer Center Hospital Tokyo 104‐0045 Japan
| | - Tetsu Nakaichi
- Radiation Safety and Quality Assurance Division National Cancer Center Hospital Tokyo 104‐0045 Japan
| | - Yuka Urago
- Radiation Safety and Quality Assurance Division National Cancer Center Hospital Tokyo 104‐0045 Japan
| | - Ako Aikawa
- Department of Radiological Technology National Cancer Center Hospital Tokyo 104‐0045 Japan
| | - Shyouichi Katsuta
- Department of Radiological Technology National Cancer Center Hospital Tokyo 104‐0045 Japan
| | - Satoshi Nakamura
- Radiation Safety and Quality Assurance Division National Cancer Center Hospital Tokyo 104‐0045 Japan
| | - Hiroshi Igaki
- Department of Radiation Oncology National Cancer Center Hospital Tokyo 104‐0045 Japan
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6
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Okamoto H, Kito S, Tohyama N, Yonai S, Kawamorita R, Nakamura M, Fujimoto T, Tani S, Yomoda A, Isobe T, Furukawa H, Kotaka K, Itami J, Ikushima H, Dokiya T, Shioyama Y. Radiation protection in radiological imaging: a survey of imaging modalities used in Japanese institutions for verifying applicator placements in high-dose-rate brachytherapy. JOURNAL OF RADIATION RESEARCH 2021; 62:58-66. [PMID: 33074329 PMCID: PMC7779356 DOI: 10.1093/jrr/rraa088] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Revised: 08/02/2020] [Accepted: 06/23/2020] [Indexed: 06/11/2023]
Abstract
Institutional imaging protocols for the verification of brachytherapy applicator placements were investigated in a survey study of domestic radiotherapy institutions. The survey form designed by a free on-line survey system was distributed via the mailing-list system of the Japanese Society for Radiation Oncology. Survey data of 75 institutions between August 2019 and October 2019 were collected. The imaging modalities used were dependent on resources available to the institutions. The displacement of a brachytherapy applicator results in significant dosimetric impact. It is essential to verify applicator placements using imaging modalities before treatment. Various imaging modalities used in institutions included a computed tomography (CT) scanner, an angiography X-ray system, a multi-purpose X-ray system and a radiotherapy simulator. The median total exposure time in overall treatment sessions was $\le$75 s for gynecological and prostate cancers. Some institutions used fluoroscopy to monitor the brachytherapy source movement. Institutional countermeasures for reducing unwanted imaging dose included minimizing the image area, changing the imaging orientation, reducing the imaging frequency and optimizing the imaging conditions. It is worth noting that half of the institutions did not confirm imaging dose regularly. This study reported on the usage of imaging modalities for brachytherapy in Japan. More caution should be applied with interstitial brachytherapy with many catheters that can lead to potentially substantial increments in imaging doses for monitoring the actual brachytherapy source using fluoroscopy. It is necessary to share imaging techniques, standardize imaging protocols and quality assurance/quality control among institutions, and imaging dose guidelines for optimization of imaging doses delivered in radiotherapy should be developed.
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Affiliation(s)
- Hiroyuki Okamoto
- Department of Medical Physics, National Cancer Center Hospital, 5-1-1 Tsukiji, Chuo-ku Tokyo, 104-0045, Japan
| | - Satoshi Kito
- Department of Radiotherapy, Tokyo Metropolitan Bokutoh Hospital, 4-23-15 Koutoubashi, Sumida-ku Tokyo, 130-8575, Japan
- Department of Radiotherapy, Tokyo Metropolitan Cancer and Infectious Diseases Center Komagome Hospital, 3-18 Honkomagome, Bunkyo-ku Tokyo, 113-8677, Japan
- Division of Medical Physics, Department of Information Technology and Medical Engineering, Human Health Sciences, Graduate School of Medicine, Kyoto University 53 Shogoin-Kawaharacho, Sakyo-ku Kyoto, Kyoto, 606-8507, Japan
| | - Naoki Tohyama
- Division ofMedical Physics,Tokyo Bay Advanced Imaging & Radiation Oncology Makuhari Clinic, 1-17 Toyosuna, Mihama-ku Chiba, Chiba, 261-0024, Japan
| | - Shunsuke Yonai
- Department of Accelerator and Medical Physics, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, 4-9-1 Anagawa, Inage-ku Chiba, Chiba, 263-8555, Japan
| | - Ryu Kawamorita
- Department of Radiation Oncology, Tane General Hospital, 1-12-21 Kujyouminami, Nishi-ku Osaka, Osaka, 550-0025, Japan
| | - Masaru Nakamura
- Department of Radiology, Aichi Medical University Hospital, 1-1 Yazakokarimata, Nagakute, Aichi, 480-1195, Japan
| | - Takahiro Fujimoto
- Division of Clinical Radiology Service, Kyoto University Hospital, 54 Shogoin-Kawaharacho, Sakyo-ku Kyoto, Kyoto, 606-8507, Japan
| | - Syoji Tani
- Department of Medical Technology, Osaka General Medical Center, 3-1-56 Bandaihigashi, Sumiyoshi-ku Osaka, Osaka, 558-8558, Japan
| | - Akihiro Yomoda
- Technical Section, Medical Equipment Business, Chiyoda Technol Corporation, 1-7 Yushima, Bunkyo-ku Tokyo, 101-0021, Japan
| | - Toru Isobe
- Oncology Product Marketing Manager, Elekta K.K, 3-9-1 Shibaura, Minato-ku Tokyo, 108-0023, Japan
| | - Hiroshi Furukawa
- Japan Medical Imaging and Radiological Systems Industries Association, 2-2-23 Koraku, Bunkyo-ku, Tokyo, 112-0004, Japan
| | - Kikuo Kotaka
- Nuclear Safety Technology Center, 5-1-3-101 Hakusan, Bunkyo-ku, Tokyo, 112-8604, Japan
| | - Jun Itami
- Department of Radiation Oncology, National Cancer Center Hospital, 5-1-1 Tsukiji, Chuo-ku Tokyo, 104-0045 Japan
| | - Hitoshi Ikushima
- Department of Therapeutic Radiology, Institute of Biomedical Sciences, Tokushima University Graduate School, 3-18-15 Kuramoto-cho, Tokushima, Tokushima, 770-8503, Japan
| | - Takushi Dokiya
- Department of Radiology, Kyoundo Hospital, 1-8 Kandasurugadai, Chiyoda-ku Tokyo, 101-0062, Japan
| | - Yoshiyuki Shioyama
- Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku Fukuoka, Fukuoka, 812-8582, Japan
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Yogo K, Noguchi Y, Okudaira K, Nozawa M, Ishiyama H, Okamoto H, Yasuda H, Oguchi H, Yamamoto S. Source position measurement by Cherenkov emission imaging from applicators for high-dose-rate brachytherapy. Med Phys 2020; 48:488-499. [PMID: 33216999 DOI: 10.1002/mp.14606] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Revised: 10/19/2020] [Accepted: 11/12/2020] [Indexed: 11/12/2022] Open
Abstract
PURPOSE We developed a novel and simple method to measure the source positions in applicators directly for high-dose-rate (HDR) brachytherapy based on Cherenkov emission imaging, and evaluated the performance. METHODS The light emission from plastic applicators used in cervical cancer treatments, irradiated by an 192 Ir γ-ray source, was captured using a charge-coupled device camera. Moreover, we attached plastics of different shapes, including tapes, tubes, and plates to a metal applicator, to use as screens for the Cherenkov imaging. We determined the source positions and dwell intervals from the light profiles along with the applicator and compared these with preset values and dummy marker measurements. RESULTS The source positions and dwell intervals measured from the light images were comparable to the dummy marker measurements and preset values. The distance from the applicator tip to the first source positions agreed with the dummy marker measurements within 0.2 mm for the plastic tandem. The dwell intervals measured using the Cherenkov method agreed with the preset values within 0.6 mm. The distances measured with three plastic types on the metal applicator also agreed with the dummy marker measurements within 0.2 mm. The dwell intervals measured using the plastic tape agreed with the preset values within 0.7 mm. CONCLUSIONS The proposed method should be suitable for rapid and easy quality assurance (QA) investigations in HDR brachytherapy, as it enables source position using a single image. The method allows for real-time, filmless measurements of the source positions to be obtained and is useful for rapid feedback in QA procedures.
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Affiliation(s)
- Katsunori Yogo
- Graduate School of Medicine, Nagoya University, 1-1-20 Daiko-minami, Higashi-ku, Nagoya, Aichi, 461-8673, Japan
| | - Yumiko Noguchi
- Department of Radiological Technology, Nagoya University Hospital, 65 Tsurumai-cho, Showa-ku, Nagoya, 466-8560, Japan
| | - Kuniyasu Okudaira
- Department of Radiological Technology, Nagoya University Hospital, 65 Tsurumai-cho, Showa-ku, Nagoya, 466-8560, Japan
| | - Marika Nozawa
- School of Medicine, Kitasato University, 1-15-1 Kitasato, Minami, Sagamihara, Kanagawa, 252-0373, Japan
| | - Hiromichi Ishiyama
- School of Medicine, Kitasato University, 1-15-1 Kitasato, Minami, Sagamihara, Kanagawa, 252-0373, Japan
| | - Hiroyuki Okamoto
- Department of Medical Physics, National Cancer Center Hospital, 5-1-1 Tsukiji, Chuo-ku, Tokyo, 104-0045, Japan
| | - Hiroshi Yasuda
- Department of Radiation Biophysics, Hiroshima University, Kasumi 1-2-3, Minami-ku, Hiroshima, 734-8553, Japan
| | - Hiroshi Oguchi
- Graduate School of Medicine, Nagoya University, 1-1-20 Daiko-minami, Higashi-ku, Nagoya, Aichi, 461-8673, Japan
| | - Seiichi Yamamoto
- Graduate School of Medicine, Nagoya University, 1-1-20 Daiko-minami, Higashi-ku, Nagoya, Aichi, 461-8673, Japan
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8
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Aldelaijan S, Devic S, Bekerat H, Papaconstadopoulos P, Schneider J, Seuntjens J, Cormack RA, Buzurovic IM. Positional and angular tracking of HDR 192 Ir source for brachytherapy quality assurance using radiochromic film dosimetry. Med Phys 2020; 47:6122-6139. [PMID: 33064876 DOI: 10.1002/mp.14540] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Revised: 08/31/2020] [Accepted: 09/25/2020] [Indexed: 11/06/2022] Open
Abstract
PURPOSE To quantify and verify the dosimetric impact of high-dose rate (HDR) source positional uncertainty in brachytherapy, and to introduce a model for three-dimensional (3D) position tracking of the HDR source based on a two-dimensional (2D) measurement. This model has been utilized for the development of a comprehensive source quality assurance (QA) method using radiochromic film (RCF) dosimetry including assessment of different digitization uncertainties. METHODS An algorithm was developed and verified to generate 2D dose maps of the mHDR-V2 192 Ir source (Elekta, Veenendaal, Netherlands) based on the AAPM TG-43 formalism. The limits of the dosimetric error associated with source (0.9 mm diameter) positional uncertainty were evaluated and experimentally verified with EBT3 film measurements for 6F (2.0 mm diameter) and 4F (1.3 mm diameter) size catheters at the surface (4F, 6F) and 10 mm further (4F only). To quantify this uncertainty, a source tracking model was developed to incorporate the unique geometric features of all isodose lines (IDLs) within any given 2D dose map away from the source. The tracking model normalized the dose map to its maximum, then quantified the IDLs using blob analysis based on features such as area, perimeter, weighted centroid, elliptic orientation, and circularity. The Pearson correlation coefficients (PCCs) between these features and source coordinates (x, y, z, θy , θz ) were calculated. To experimentally verify the accuracy of the tracking model, EBT3 film pieces were positioned within a Solid Water® (SW) phantom above and below the source and they were exposed simultaneously. RESULTS The maximum measured dosimetric variations on the 6F and 4F catheter surfaces were 39.8% and 36.1%, respectively. At 10 mm further, the variation reduced to 2.6% for the 4F catheter which is in agreement with the calculations. The source center (x, y) was strongly correlated with the low IDL-weighted centroid (PCC = 0.99), while the distance to source (z) was correlated with the IDL areas (PCC = 0.96) and perimeters (PCC = 0.99). The source orientation θy was correlated with the difference between high and low IDL-weighted centroids (PCC = 0.98), while θz was correlated with the elliptic orientation of the 60-90% IDLs (PCC = 0.97) for a maximum distance of z = 5 mm. Beyond 5 mm, IDL circularity was significant, therefore limiting the determination of θz (PCC ≤ 0.48). The measured positional errors from the film sets above and below the source indicated a source position at the bottom of the catheter (-0.24 ± 0.07 mm). CONCLUSIONS Isodose line features of a 2D dose map away from the HDR source can reveal its spatial coordinates. RCF was shown to be a suitable dosimeter for source tracking and dosimetry. This technique offers a novel source QA method and has the potential to be used for QA of commercial and customized applicators.
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Affiliation(s)
- Saad Aldelaijan
- Department of Radiation Oncology, Dana Farber/Brigham and Women's Cancer Center, Harvard Medical School, Boston, MA, 02115, USA.,Department of Biomedical Engineering, Montreal Neurological Institute, McGill University, Montréal, QC, H3A 2B4, Canada.,Medical Physics Unit, McGill University, Montréal, QC, H4A 3J1, Canada.,Department of Radiation Oncology, SMBD Jewish General Hospital, Montréal, QC, H3T 1E2, Canada.,Biomedical Physics Department, King Faisal Specialist Hospital & Research Centre, Riyadh, 12713, Saudi Arabia
| | - Slobodan Devic
- Medical Physics Unit, McGill University, Montréal, QC, H4A 3J1, Canada.,Department of Radiation Oncology, SMBD Jewish General Hospital, Montréal, QC, H3T 1E2, Canada
| | - Hamed Bekerat
- Department of Radiation Oncology, SMBD Jewish General Hospital, Montréal, QC, H3T 1E2, Canada
| | | | - James Schneider
- Department of Radiation Oncology, SMBD Jewish General Hospital, Montréal, QC, H3T 1E2, Canada
| | - Jan Seuntjens
- Medical Physics Unit, McGill University, Montréal, QC, H4A 3J1, Canada
| | - Robert A Cormack
- Department of Radiation Oncology, Dana Farber/Brigham and Women's Cancer Center, Harvard Medical School, Boston, MA, 02115, USA
| | - Ivan M Buzurovic
- Department of Radiation Oncology, Dana Farber/Brigham and Women's Cancer Center, Harvard Medical School, Boston, MA, 02115, USA
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9
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Yogo K, Matsushita A, Tatsuno Y, Shimo T, Hirota S, Nozawa M, Ozawa S, Ishiyama H, Yasuda H, Nagata Y, Hayakawa K. Imaging Cherenkov emission for quality assurance of high-dose-rate brachytherapy. Sci Rep 2020; 10:3572. [PMID: 32108157 PMCID: PMC7046619 DOI: 10.1038/s41598-020-60519-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2019] [Accepted: 02/12/2020] [Indexed: 11/26/2022] Open
Abstract
With advances in high-dose-rate (HDR) brachytherapy, the importance of quality assurance (QA) is increasing to ensure safe delivery of the treatment by measuring dose distribution and positioning the source with much closer intervals for highly active sources. However, conventional QA is time-consuming, involving the use of several different measurement tools. Here, we developed simple QA method for HDR brachytherapy based on the imaging of Cherenkov emission and evaluated its performance. Light emission from pure water irradiated by an 192Ir γ-ray source was captured using a charge-coupled device camera. Monte Carlo calculations showed that the observed light was primarily Cherenkov emissions produced by Compton-scattered electrons from the γ-rays. The uncorrected Cherenkov light distribution, which was 5% on average except near the source (within 7 mm from the centre), agreed with the dose distribution calculated using the treatment planning system. The accuracy was attributed to isotropic radiation and short-range Compton electrons. The source positional interval, as measured from the light images, was comparable to the expected intervals, yielding spatial resolution similar to that permitted by conventional film measurements. The method should be highly suitable for quick and easy QA investigations of HDR brachytherapy as it allows simultaneous measurements of dose distribution, source strength, and source position using a single image.
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Affiliation(s)
- Katsunori Yogo
- Graduate School of Medicine, Nagoya University, 1-1-20 Daiko-minami, Higashi-ku, Nagoya, Aichi, 461-8673, Japan.
- Graduate School of Medical Science, Kitasato University, 1-15-1 Kitasato, Minami, Sagamihara, Kanagawa, 252-0373, Japan.
| | - Akihiro Matsushita
- Graduate School of Medical Science, Kitasato University, 1-15-1 Kitasato, Minami, Sagamihara, Kanagawa, 252-0373, Japan
| | - Yuya Tatsuno
- Graduate School of Medical Science, Kitasato University, 1-15-1 Kitasato, Minami, Sagamihara, Kanagawa, 252-0373, Japan
| | - Takahiro Shimo
- Department of Radiology, Tokyo Nishi Tokushukai Hospital, 3-1-1 Matsubara-cho, Akishima, Tokyo, 196-0003, Japan
| | - Seiko Hirota
- Department of Radiation Biophysics, Research Institute for Radiation Biology and Medicine, Hiroshima University, Kasumi 1-2-3, Minami-ku, Hiroshima, 734-8553, Japan
| | - Marika Nozawa
- School of Medicine, Kitasato University, 1-15-1 Kitasato, Minami, Sagamihara, Kanagawa, 252-0373, Japan
| | - Shuichi Ozawa
- Hiroshima High Precision Radiotherapy Cancer Center, 3-2-2 Futabanosato, Higashi-ku, Hiroshima, 732-0057, Japan
- Department of Radiation Oncology, Hiroshima University Hospital, 1-2-3 Kasumi, Minami-ku, Hiroshima, 734-8551, Japan
| | - Hiromichi Ishiyama
- Graduate School of Medical Science, Kitasato University, 1-15-1 Kitasato, Minami, Sagamihara, Kanagawa, 252-0373, Japan
- School of Medicine, Kitasato University, 1-15-1 Kitasato, Minami, Sagamihara, Kanagawa, 252-0373, Japan
| | - Hiroshi Yasuda
- Department of Radiation Biophysics, Research Institute for Radiation Biology and Medicine, Hiroshima University, Kasumi 1-2-3, Minami-ku, Hiroshima, 734-8553, Japan
| | - Yasushi Nagata
- Hiroshima High Precision Radiotherapy Cancer Center, 3-2-2 Futabanosato, Higashi-ku, Hiroshima, 732-0057, Japan
- Department of Radiation Oncology, Hiroshima University Hospital, 1-2-3 Kasumi, Minami-ku, Hiroshima, 734-8551, Japan
| | - Kazushige Hayakawa
- Graduate School of Medical Science, Kitasato University, 1-15-1 Kitasato, Minami, Sagamihara, Kanagawa, 252-0373, Japan
- School of Medicine, Kitasato University, 1-15-1 Kitasato, Minami, Sagamihara, Kanagawa, 252-0373, Japan
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10
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Jung H, Shen C, Gonzalez Y, Albuquerque K, Jia X. Deep-learning assisted automatic digitization of interstitial needles in 3D CT image based high dose-rate brachytherapy of gynecological cancer. Phys Med Biol 2019; 64:215003. [PMID: 31470425 DOI: 10.1088/1361-6560/ab3fcb] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Digitization of interstitial needles is a complicated and tedious process for the treatment planning of 3D CT image based interstitial high dose-rate brachytherapy (HDRBT) of gynecological cancer. We developed a deep-learning assisted auto-digitization method for interstitial needles. The digitization method consisted of two steps. The first step used a deep neural network with a U-net structure to segment all needles from CT images. The second step simultaneously clustered the segmented voxels into different needle groups and generated the needle central trajectories by solving an optimization problem. We evaluated the effectiveness of the developed method in ten interstitial HDRBT patient cases that were not used in the training of the U-net. Average number of needles per case was 20.7. For the segmentation step, average Dice similarity coefficient between automatic and manual segmentation was 0.93. For the digitization step, Hausdorff distance between needle trajectories determined by our method and manually by qualified medical physicists was ~0.71 mm on average and mean difference of tip positions was ~0.63 mm, which were considered acceptable for HDRBT treatment planning. It took ~5 min to complete the digitization process of an interstitial HDRBT case. The achieved accuracy and efficiency made our method clinically attractive.
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Affiliation(s)
- Hyunuk Jung
- Medical Artificial Intelligence and Automation (MAIA) Lab, University of Texas Southwestern Medical Center, Dallas, TX 75235, United States of America. Innovative Technology Of Radiotherapy Computation and Hardware (iTORCH) Lab, University of Texas Southwestern Medical Center, Dallas, TX 75235, United States of America. Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, TX 75235, United States of America
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11
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Jung H, Gonzalez Y, Shen C, Klages P, Albuquerque K, Jia X. Deep-learning-assisted automatic digitization of applicators in 3D CT image-based high-dose-rate brachytherapy of gynecological cancer. Brachytherapy 2019; 18:841-851. [PMID: 31345749 DOI: 10.1016/j.brachy.2019.06.003] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2019] [Revised: 05/22/2019] [Accepted: 06/07/2019] [Indexed: 11/18/2022]
Abstract
PURPOSE Applicator digitization is one of the most critical steps in 3D high-dose-rate brachytherapy (HDRBT) treatment planning. Motivated by recent advances in deep-learning, we propose a deep-learning-assisted applicator digitization method for 3D CT image-based HDRBT. This study demonstrates its feasibility and potential in gynecological cancer HDRBT. METHODS AND MATERIALS Our method consisted of two steps. The first step used a U-net to segment applicator regions. We trained the U-net using two-dimensional CT images with a tandem-and-ovoid (T&O) applicator and corresponding applicator mask images. The second step applied a spectral clustering method and a polynomial curve fitting method to extract applicator central paths. We evaluated the accuracy, efficiency, and robustness of our method in different scenarios including other T&O cases that were not used in training, a T&O case scanned with cone-beam CT, and Y-tandem and cylinder-applicator cases. RESULTS In test cases with a T&O applicator, average 3D Dice similarity coefficient between automatic and manual segmented applicator regions was 0.93. Average distance between tip positions and average Hausdorff distance between applicator channels determined by our method and manually were 0.64 mm and 0.68 mm, respectively. Although trained only using CT images of T&O cases, our tool can also digitize Y-tandem, cylinder applicator, and T&O applicator scanned in cone-beam CT with error of tip position and Hausdorff distance <1 mm. Computation time was ∼15 s per case. CONCLUSIONS We have developed a deep-learning-assisted applicator digitization tool for 3D CT image-based HDRBT of gynecological cancer. The achieved accuracy, efficiency, and robustness made our tool clinically attractive.
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Affiliation(s)
- Hyunuk Jung
- Innovation Technology of Radiotherapy Computation and Hardware (iTORCH) Lab, University of Texas Southwestern Medical Center, Dallas, TX; Medical Artificial Intelligence and Automation (MAIA) Lab, University of Texas Southwestern Medical Center, Dallas, TX; Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, TX
| | - Yesenia Gonzalez
- Innovation Technology of Radiotherapy Computation and Hardware (iTORCH) Lab, University of Texas Southwestern Medical Center, Dallas, TX; Medical Artificial Intelligence and Automation (MAIA) Lab, University of Texas Southwestern Medical Center, Dallas, TX; Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, TX
| | - Chenyang Shen
- Innovation Technology of Radiotherapy Computation and Hardware (iTORCH) Lab, University of Texas Southwestern Medical Center, Dallas, TX; Medical Artificial Intelligence and Automation (MAIA) Lab, University of Texas Southwestern Medical Center, Dallas, TX; Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, TX
| | - Peter Klages
- Innovation Technology of Radiotherapy Computation and Hardware (iTORCH) Lab, University of Texas Southwestern Medical Center, Dallas, TX; Medical Artificial Intelligence and Automation (MAIA) Lab, University of Texas Southwestern Medical Center, Dallas, TX; Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, TX
| | - Kevin Albuquerque
- Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, TX
| | - Xun Jia
- Innovation Technology of Radiotherapy Computation and Hardware (iTORCH) Lab, University of Texas Southwestern Medical Center, Dallas, TX; Medical Artificial Intelligence and Automation (MAIA) Lab, University of Texas Southwestern Medical Center, Dallas, TX; Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, TX.
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12
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Poder J, Cutajar D, Guatelli S, Petasecca M, Howie A, Bucci J, Rosenfeld A. HDR brachytherapy in vivo source position verification using a 2D diode array: A Monte Carlo study. J Appl Clin Med Phys 2018; 19:163-172. [PMID: 29855128 PMCID: PMC6036394 DOI: 10.1002/acm2.12360] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2018] [Revised: 03/21/2018] [Accepted: 04/18/2018] [Indexed: 11/23/2022] Open
Abstract
PURPOSE This study aims to assess the accuracy of source position verification during high-dose rate (HDR) prostate brachytherapy using a novel, in-house developed two-dimensional (2D) diode array (the Magic Plate), embedded exactly below the patient within a carbon fiber couch. The effect of tissue inhomogeneities on source localization accuracy is examined. METHOD Monte Carlo (MC) simulations of 12 source positions from a HDR prostate brachytherapy treatment were performed using the Geant4 toolkit. An Ir-192 Flexisource (Isodose Control, Veenendaal, the Netherlands) was simulated inside a voxelized patient geometry, and the dose deposited in each detector of the Magic Plate evaluated. The dose deposited in each detector was then used to localize the source position using a proprietary reconstruction algorithm. RESULTS The accuracy of source position verification using the Magic Plate embedded in the patient couch was found to be affected by the tissue inhomogeneities within the patient, with an average difference of 2.1 ± 0.8 mm (k = 1) between the Magic Plate predicted and known source positions. Recalculation of the simulations with all voxels assigned a density of water improved this verification accuracy to within 1 mm. CONCLUSION Source position verification using the Magic Plate during a HDR prostate brachytherapy treatment was examined using MC simulations. In a homogenous geometry (water), the Magic Plate was able to localize the source to within 1 mm, however, the verification accuracy was negatively affected by inhomogeneities; this can be corrected for by using density information obtained from CT, making the proposed tool attractive for use as a real-time in vivo quality assurance (QA) device in HDR brachytherapy for prostate cancer.
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Affiliation(s)
- Joel Poder
- Centre of Medical Radiation PhysicsUniversity of WollongongWollongongNSWAustralia
- St George Hospital Cancer Care CentreKogarahNSWAustralia
| | - Dean Cutajar
- Centre of Medical Radiation PhysicsUniversity of WollongongWollongongNSWAustralia
- St George Hospital Cancer Care CentreKogarahNSWAustralia
| | - Susanna Guatelli
- Centre of Medical Radiation PhysicsUniversity of WollongongWollongongNSWAustralia
| | - Marco Petasecca
- Centre of Medical Radiation PhysicsUniversity of WollongongWollongongNSWAustralia
| | - Andrew Howie
- St George Hospital Cancer Care CentreKogarahNSWAustralia
| | - Joseph Bucci
- St George Hospital Cancer Care CentreKogarahNSWAustralia
| | - Anatoly Rosenfeld
- Centre of Medical Radiation PhysicsUniversity of WollongongWollongongNSWAustralia
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13
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Cawston-Grant B, Morrison H, Sloboda RS, Menon G. Experimental assessment of the Advanced Collapsed-cone Engine for scalp brachytherapy treatments. Brachytherapy 2017; 17:489-499. [PMID: 29239813 DOI: 10.1016/j.brachy.2017.10.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2017] [Revised: 10/17/2017] [Accepted: 10/17/2017] [Indexed: 12/19/2022]
Abstract
PURPOSE To experimentally assess the performance of the Advanced Collapsed-cone Engine (ACE) for 192Ir high-dose-rate brachytherapy treatment planning of nonmelanoma skin cancers of the scalp. METHODS AND MATERIALS A layered slab phantom was designed to model the head (skin, skull, and brain) and surface treatment mold using tissue equivalent materials. Six variations of the phantom were created by varying skin thickness, skull thickness, and size of air gap between the mold and skin. Treatment planning was initially performed using the Task Group 43 (TG-43) formalism with CT images of each phantom variation. Doses were recalculated using standard and high accuracy modes of ACE. The plans were delivered to Gafchromic EBT3 film placed between different layers of the phantom. RESULTS Doses calculated by TG-43 and ACE and those measured by film agreed with each other at most locations within the phantoms. For a given phantom variation, average TG-43- and ACE-calculated doses were similar, with a maximum difference of (3 ± 12)% (k = 2). Compared to the film measurements, TG-43 and ACE overestimated the film-measured dose by (13 ± 12)% (k = 2) for one phantom variation below the skull layer. CONCLUSIONS TG-43- and ACE-calculated and film-measured doses were found to agree above the skull layer of the phantom, which is where the tumor would be located in a clinical case. ACE appears to underestimate the attenuation through bone relative to that measured by film; however, the dose to bone is below tolerance levels for this treatment.
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Affiliation(s)
- Brie Cawston-Grant
- Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada.
| | - Hali Morrison
- Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada; Department of Medical Physics, Cross Cancer Institute, Edmonton, Alberta, Canada
| | - Ron S Sloboda
- Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada; Department of Medical Physics, Cross Cancer Institute, Edmonton, Alberta, Canada
| | - Geetha Menon
- Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada; Department of Medical Physics, Cross Cancer Institute, Edmonton, Alberta, Canada
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14
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Okamoto H, Nakamura S, Nishioka S, Iijima K, Wakita A, Abe Y, Tohyama N, Kawamura S, Minemura T, Itami J. Independent assessment of source position for gynecological applicator in high-dose-rate brachytherapy. J Contemp Brachytherapy 2017; 9:477-486. [PMID: 29204169 PMCID: PMC5705831 DOI: 10.5114/jcb.2017.70952] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2017] [Accepted: 09/05/2017] [Indexed: 11/17/2022] Open
Abstract
PURPOSE The aim of this study is to describe a phantom designed for independent examination of a source position in brachytherapy that is suitable for inclusion in an external auditing program. MATERIAL AND METHODS We developed a phantom that has a special design and a simple mechanism, capable of firmly fixing a radiochromic film and tandem-ovoid applicators to assess discrepancies in source positions between the measurements and treatment planning system (TPS). Three tests were conducted: 1) reproducibility of the source positions (n = 5); 2) source movements inside the applicator tube; 3) changing source position by changing curvature of the transfer tubes. In addition, as a trial study, the phantom was mailed to 12 institutions, and 23 trial data sets were examined. The source displacement ΔX and ΔY (reference = TPS) were expressed according to the coordinates, in which the positive direction on the X-axis corresponds to the external side of the applicator perpendicular to source transfer direction Y-axis. RESULTS Test 1: The 1σ fell within 1 mm irrespective of the dwell positions. Test 2: ΔX were greater around the tip of the applicator owing to the source cable. Test 3: All of the source position changes fell within 1 mm. For postal audit, the mean and 1.96σ in ΔX were 0.8 and 0.8 mm, respectively. Almost all data were located within a positive region along the X-axis due to the source cable. The mean and 1.96σ in ΔY were 0.3 and 1.6 mm, respectively. The variance in ΔY was greater than that in ΔX, and large uncertainties exist in the determination of the first dwell position. The 95% confidence limit was 2.1 mm. CONCLUSIONS In HDR brachytherapy, an effectiveness of independent source position assessment could be demonstrated. The 95% confidence limit was 2.1 mm for a tandem-ovoids applicator.
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Affiliation(s)
- Hiroyuki Okamoto
- Department of Radiation Oncology, National Cancer Center Hospital, Tokyo
| | - Satoshi Nakamura
- Department of Radiation Oncology, National Cancer Center Hospital, Tokyo
| | - Shie Nishioka
- Department of Radiation Oncology, National Cancer Center Hospital, Tokyo
| | - Kotaro Iijima
- Department of Radiation Oncology, National Cancer Center Hospital, Tokyo
| | - Akihisa Wakita
- Department of Radiation Oncology, National Cancer Center Hospital, Tokyo
| | - Yukinao Abe
- Department of Radiology, Chiba University Hospital, Chiba
| | - Naoki Tohyama
- Division of Medical Physics, Tokyo Bay Advanced Imaging & Radiation Oncology Clinic, Chiba
| | - Shinji Kawamura
- Department of Radiological Technology, Faculty of Fukuoka Medical Technology, Teikyo University, Fukuoka
| | - Toshiyuki Minemura
- Center for Cancer Control and Information Services, National Cancer Center, Tokyo, Japan
| | - Jun Itami
- Department of Radiation Oncology, National Cancer Center Hospital, Tokyo
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A tool to automatically analyze electromagnetic tracking data from high dose rate brachytherapy of breast cancer patients. PLoS One 2017; 12:e0183608. [PMID: 28934238 PMCID: PMC5608198 DOI: 10.1371/journal.pone.0183608] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2017] [Accepted: 08/08/2017] [Indexed: 11/30/2022] Open
Abstract
During High Dose Rate Brachytherapy (HDR-BT) the spatial position of the radiation source inside catheters implanted into a female breast is determined via electromagnetic tracking (EMT). Dwell positions and dwell times of the radiation source are established, relative to the patient’s anatomy, from an initial X-ray-CT-image. During the irradiation treatment, catheter displacements can occur due to patient movements. The current study develops an automatic analysis tool of EMT data sets recorded with a solenoid sensor to assure concordance of the source movement with the treatment plan. The tool combines machine learning techniques such as multi-dimensional scaling (MDS), ensemble empirical mode decomposition (EEMD), singular spectrum analysis (SSA) and particle filter (PF) to precisely detect and quantify any mismatch between the treatment plan and actual EMT measurements. We demonstrate that movement artifacts as well as technical signal distortions can be removed automatically and reliably, resulting in artifact-free reconstructed signals. This is a prerequisite for a highly accurate determination of any deviations of dwell positions from the treatment plan.
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16
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Götz TI, Lahmer G, Brandt T, Kallis K, Strnad V, Bert C, Hensel B, Tomé AM, Lang EW. On the use of particle filters for electromagnetic tracking in high dose rate brachytherapy. Phys Med Biol 2017; 62:7617-7640. [PMID: 28796645 DOI: 10.1088/1361-6560/aa8591] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Modern radiotherapy of female breast cancers often employs high dose rate brachytherapy, where a radioactive source is moved inside catheters, implanted in the female breast, according to a prescribed treatment plan. Source localization relative to the patient's anatomy is determined with solenoid sensors whose spatial positions are measured with an electromagnetic tracking system. Precise sensor dwell position determination is of utmost importance to assure irradiation of the cancerous tissue according to the treatment plan. We present a hybrid data analysis system which combines multi-dimensional scaling with particle filters to precisely determine sensor dwell positions in the catheters during subsequent radiation treatment sessions. Both techniques are complemented with empirical mode decomposition for the removal of superimposed breathing artifacts. We show that the hybrid model robustly and reliably determines the spatial positions of all catheters used during the treatment and precisely determines any deviations of actual sensor dwell positions from the treatment plan. The hybrid system only relies on sensor positions measured with an EMT system and relates them to the spatial positions of the implanted catheters as initially determined with a computed x-ray tomography.
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Affiliation(s)
- Th I Götz
- CIML, Biophysics, University of Regensburg, 93040 Regensburg, Germany. Department of Radiation Oncology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, 91054 Erlangen, Germany
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17
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Okamoto H, Wakita A, Nakamura S, Nishioka S, Aikawa A, Kato T, Abe Y, Kobayashi K, Inaba K, Murakami N, Itami J. Dosimetric impact of an air passage on intraluminal brachytherapy for bronchus cancer. JOURNAL OF RADIATION RESEARCH 2016; 57:637-645. [PMID: 27605630 PMCID: PMC5137293 DOI: 10.1093/jrr/rrw072] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/22/2015] [Revised: 02/16/2016] [Accepted: 05/17/2016] [Indexed: 06/06/2023]
Abstract
The brachytherapy dose calculations used in treatment planning systems (TPSs) have conventionally been performed assuming homogeneous water. Using measurements and a Monte Carlo simulation, we evaluated the dosimetric impact of an air passage on brachytherapy for bronchus cancer. To obtain the geometrical characteristics of an air passage, we analyzed the anatomical information from CT images of patients who underwent intraluminal brachytherapy using a high-dose-rate 192Ir source (MicroSelectron V2r®, Nucletron). Using an ionization chamber, we developed a measurement system capable of measuring the peripheral dose with or without an air cavity surrounding the catheter. Air cavities of five different radii (0.3, 0.5, 0.75, 1.25 and 1.5 cm) were modeled by cylindrical tubes surrounding the catheter. A Monte Carlo code (GEANT4) was also used to evaluate the dosimetric impact of the air cavity. Compared with dose calculations in homogeneous water, the measurements and GEANT4 indicated a maximum overdose of 5-8% near the surface of the air cavity (with the maximum radius of 1.5 cm). Conversely, they indicated a minimum overdose of ~1% in the region 3-5 cm from the cavity surface for the smallest radius of 0.3 cm. The dosimetric impact depended on the size and the distance of the air passage, as well as the length of the treatment region. Based on dose calculations in water, the TPS for intraluminal brachytherapy for bronchus cancer had an unexpected overdose of 3-5% for a mean radius of 0.75 cm. This study indicates the need for improvement in dose calculation accuracy with respect to intraluminal brachytherapy for bronchus cancer.
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Affiliation(s)
- Hiroyuki Okamoto
- Department of Radiation Oncology, National Cancer Center Hospital, 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0045, Japan
| | - Akihisa Wakita
- Department of Radiation Oncology, National Cancer Center Hospital, 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0045, Japan
| | - Satoshi Nakamura
- Department of Radiation Oncology, National Cancer Center Hospital, 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0045, Japan
| | - Shie Nishioka
- Department of Radiation Oncology, National Cancer Center Hospital, 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0045, Japan
| | - Ako Aikawa
- Department of Radiation Oncology, National Cancer Center Hospital, 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0045, Japan
| | - Toru Kato
- Department of Radiation Oncology, National Cancer Center Hospital, 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0045, Japan
| | - Yoshihisa Abe
- Department of Radiation Oncology, National Cancer Center Hospital, 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0045, Japan
| | - Kazuma Kobayashi
- Department of Radiation Oncology, National Cancer Center Hospital, 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0045, Japan
| | - Koji Inaba
- Department of Radiation Oncology, National Cancer Center Hospital, 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0045, Japan
| | - Naoya Murakami
- Department of Radiation Oncology, National Cancer Center Hospital, 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0045, Japan
| | - Jun Itami
- Department of Radiation Oncology, National Cancer Center Hospital, 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0045, Japan
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18
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High dose-rate endoluminal brachytherapy for primary and recurrent esophageal cancer. Strahlenther Onkol 2016; 192:458-66. [DOI: 10.1007/s00066-016-0979-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2016] [Accepted: 04/08/2016] [Indexed: 12/19/2022]
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19
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Espinoza A, Petasecca M, Fuduli I, Howie A, Bucci J, Corde S, Jackson M, Lerch MLF, Rosenfelda AB. The evaluation of a 2D diode array in “magic phantom” for use in high dose rate brachytherapy pretreatment quality assurance. Med Phys 2015; 42:663-673. [PMID: 25771556 DOI: 10.1118/1.4905233] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2014] [Revised: 12/09/2014] [Accepted: 12/16/2014] [Indexed: 11/07/2022] Open
Abstract
PURPOSE High dose rate (HDR) brachytherapy is a treatment method that is used increasingly worldwide. The development of a sound quality assurance program for the verification of treatment deliveries can be challenging due to the high source activity utilized and the need for precise measurements of dwell positions and times. This paper describes the application of a novel phantom, based on a 2D 11 × 11 diode array detection system, named “magic phantom” (MPh), to accurately measure plan dwell positions and times, compare them directly to the treatment plan, determine errors in treatment delivery, and calculate absorbed dose. METHODS The magic phantom system was CT scanned and a 20 catheter plan was generated to simulate a nonspecific treatment scenario. This plan was delivered to the MPh and, using a custom developed software suite, the dwell positions and times were measured and compared to the plan. The original plan was also modified, with changes not disclosed to the primary authors, and measured again using the device and software to determine the modifications. A new metric, the “position–time gamma index,” was developed to quantify the quality of a treatment delivery when compared to the treatment plan. The MPh was evaluated to determine the minimum measurable dwell time and step size. The incorporation of the TG-43U1 formalism directly into the software allows for dose calculations to be made based on the measured plan. The estimated dose distributions calculated by the software were compared to the treatment plan and to calibrated EBT3 film, using the 2D gamma analysis method. RESULTS For the original plan, the magic phantom system was capable of measuring all dwell points and dwell times and the majority were found to be within 0.93 mm and 0.25 s, respectively, from the plan. By measuring the altered plan and comparing it to the unmodified treatment plan, the use of the position–time gamma index showed that all modifications made could be readily detected. The MPh was able to measure dwell times down to 0.067 ± 0.001 s and planned dwell positions separated by 1 mm. The dose calculation carried out by the MPh software was found to be in agreement with values calculated by the treatment planning system within 0.75%. Using the 2D gamma index, the dose map of the MPh plane and measured EBT3 were found to have a pass rate of over 95% when compared to the original plan. CONCLUSIONS The application of this magic phantom quality assurance system to HDR brachytherapy has demonstrated promising ability to perform the verification of treatment plans, based upon the measured dwell positions and times. The introduction of the quantitative position–time gamma index allows for direct comparison of measured parameters against the plan and could be used prior to patient treatment to ensure accurate delivery.
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Espinoza A, Petasecca M, Cutajar D, Fuduli I, Howie A, Bucci J, Corde S, Jackson M, Zaider M, Lerch MLF, Rosenfeld AB. Pretreatment verification of high dose rate brachytherapy plans using the ‘magic phantom’ system. Biomed Phys Eng Express 2015. [DOI: 10.1088/2057-1976/1/2/025201] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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