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Siavashpour Z, Kiarad R, Aghamiri MR, Babaloui S, Seiri M, Jaberi R. Feasibility of using micro silica bead TLDs for in-Vivo dosimetry of CT-based HDR prostate brachytherapy: An experimental and simulation study. Appl Radiat Isot 2024; 212:111429. [PMID: 38986180 DOI: 10.1016/j.apradiso.2024.111429] [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: 02/06/2024] [Revised: 06/20/2024] [Accepted: 07/06/2024] [Indexed: 07/12/2024]
Abstract
PURPOSE Feasibility of silica-based dosimeters for IVD of HDR prostate brachytherapy. MATERIAL AND METHODS Plastic dosimeter holders and a water-fillable prostate phantom were built in-house. Interstitial prostate brachytherapy and Monte Carlo simulations were performed. The treatment planning, Monte-Carlo simulation, and dosimetry results were compared. RESULTS The relative differences between TLD-TPS, TLD-MCNP, and TPS-MCNP were 0.2-6.9 %, 0.5-6.5 %, and 0.6-6.3 %, respectively. CONCLUSION Micro-silica bead dosimeters can perform offline in situ quality assurance in HDR prostate brachytherapy.
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Affiliation(s)
- Zahra Siavashpour
- Radiotherapy Oncology Department, Shohada-e Tajrish Educational Hospital, Medical School, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
| | - Reza Kiarad
- Department of Medical Radiation Engineering, Shahid Beheshti University, Tehran, Iran.
| | - Mahmoud Reza Aghamiri
- Department of Medical Radiation Engineering, Shahid Beheshti University, Tehran, Iran
| | - Somayyeh Babaloui
- Department of Medical Physics and Biomedical Engineering, Faculty of Medicine, Tehran University of Medical Science, Tehran, Iran
| | - Mahnaz Seiri
- Department of Medical Physics and Biomedical Engineering, Faculty of Medicine, Tehran University of Medical Science, Tehran, Iran; Advanced Medical Technologies & Equipment Institute, Tehran University of Medical Science, Tehran, Iran
| | - Ramin Jaberi
- Radiation Oncology Research Center, Iran Cancer Institute, Tehran University of Medical Sciences, Tehran, Iran; Department of Physics, University of Surrey, Guildford, UK
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2
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van Wagenberg T, Voncken R, van Beveren C, Berbee M, van Limbergen E, Verhaegen F, Paiva Fonseca G. Time-resolved clinical dose volume metrics, calculations and predictions based on source tracking measurements and uncertainties to aid treatment verification and error detection for HDR brachytherapy-a proof-of-principle study. Phys Med Biol 2024; 69:135006. [PMID: 38870948 DOI: 10.1088/1361-6560/ad580e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2024] [Accepted: 06/13/2024] [Indexed: 06/15/2024]
Abstract
Objective.High-dose-rate (HDR) brachytherapy lacks routinely available treatment verification methods. Real-time tracking of the radiation source during HDR brachytherapy can enhance treatment verification capabilities. Recent developments in source tracking allow for measurement of dwell times and source positions with high accuracy. However, more clinically relevant information, such as dose discrepancies, is still needed. To address this, a real-time dose calculation implementation was developed to provide more relevant information from source tracking data. A proof-of-principle of the developed tool was shown using source tracking data obtained from a 3D-printed anthropomorphic phantom.Approach.Software was developed to calculate dose-volume-histograms (DVH) and clinical dose metrics from experimental HDR prostate treatment source tracking data, measured in a realistic pelvic phantom. Uncertainty estimation was performed using repeat measurements to assess the inherent dose measuring uncertainty of thein vivodosimetry (IVD) system. Using a novel approach, the measurement uncertainty can be incorporated in the dose calculation, and used for evaluation of cumulative dose and clinical dose-volume metrics after every dwell position, enabling real-time treatment verification.Main results.The dose calculated from source tracking measurements aligned with the generated uncertainty bands, validating the approach. Simulated shifts of 3 mm in 5/17 needles in a single plan caused DVH deviations beyond the uncertainty bands, indicating errors occurred during treatment. Clinical dose-volume metrics could be monitored in a time-resolved approach, enabling early detection of treatment plan deviations and prediction of their impact on the final dose that will be delivered in real-time.Significance.Integrating dose calculation with source tracking enhances the clinical relevance of IVD methods. Phantom measurements show that the developed tool aids in tracking treatment progress, detecting errors in real-time and post-treatment evaluation. In addition, it could be used to define patient-specific action limits and error thresholds, while taking the uncertainty of the measurement system into consideration.
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Affiliation(s)
- Teun van Wagenberg
- Department of Radiation Oncology (Maastro), GROW-Research Institute for Oncology and Reproduction, Maastricht University Medical Centre+, Maastricht, The Netherlands
| | - Robert Voncken
- Department of Radiation Oncology (Maastro), GROW-Research Institute for Oncology and Reproduction, Maastricht University Medical Centre+, Maastricht, The Netherlands
| | - Celine van Beveren
- Department of Radiation Oncology (Maastro), GROW-Research Institute for Oncology and Reproduction, Maastricht University Medical Centre+, Maastricht, The Netherlands
| | - Maaike Berbee
- Department of Radiation Oncology (Maastro), GROW-Research Institute for Oncology and Reproduction, Maastricht University Medical Centre+, Maastricht, The Netherlands
| | - Evert van Limbergen
- Department of Radiation Oncology (Maastro), GROW-Research Institute for Oncology and Reproduction, Maastricht University Medical Centre+, Maastricht, The Netherlands
| | - Frank Verhaegen
- Department of Radiation Oncology (Maastro), GROW-Research Institute for Oncology and Reproduction, Maastricht University Medical Centre+, Maastricht, The Netherlands
| | - Gabriel Paiva Fonseca
- Department of Radiation Oncology (Maastro), GROW-Research Institute for Oncology and Reproduction, Maastricht University Medical Centre+, Maastricht, The Netherlands
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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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Bui TNH, Large M, Poder J, Bucci J, Bianco E, Giampaolo RA, Rivetti A, Da Rocha Rolo M, Pastuovic Z, Corradino T, Pancheri L, Petasecca M. Preliminary Characterization of an Active CMOS Pad Detector for Tracking and Dosimetry in HDR Brachytherapy. SENSORS (BASEL, SWITZERLAND) 2024; 24:692. [PMID: 38276383 PMCID: PMC10818778 DOI: 10.3390/s24020692] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2023] [Revised: 01/15/2024] [Accepted: 01/18/2024] [Indexed: 01/27/2024]
Abstract
We assessed the accuracy of a prototype radiation detector with a built in CMOS amplifier for use in dosimetry for high dose rate brachytherapy. The detectors were fabricated on two substrates of epitaxial high resistivity silicon. The radiation detection performance of prototypes has been tested by ion beam induced charge (IBIC) microscopy using a 5.5 MeV alpha particle microbeam. We also carried out the HDR Ir-192 radiation source tracking at different depths and angular dose dependence in a water equivalent phantom. The detectors show sensitivities spanning from (5.8 ± 0.021) × 10-8 to (3.6 ± 0.14) × 10-8 nC Gy-1 mCi-1 mm-2. The depth variation of the dose is within 5% with that calculated by TG-43. Higher discrepancies are recorded for 2 mm and 7 mm depths due to the scattering of secondary particles and the perturbation of the radiation field induced in the ceramic/golden package. Dwell positions and dwell time are reconstructed within ±1 mm and 20 ms, respectively. The prototype detectors provide an unprecedented sensitivity thanks to its monolithic amplification stage. Future investigation of this technology will include the optimisation of the packaging technique.
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Affiliation(s)
- Thi Ngoc Hang Bui
- Centre for Medical Radiation Physics, University of Wollongong, Wollongong, NSW 2522, Australia; (T.N.H.B.); (M.L.); (J.P.); (J.B.)
| | - Matthew Large
- Centre for Medical Radiation Physics, University of Wollongong, Wollongong, NSW 2522, Australia; (T.N.H.B.); (M.L.); (J.P.); (J.B.)
| | - Joel Poder
- Centre for Medical Radiation Physics, University of Wollongong, Wollongong, NSW 2522, Australia; (T.N.H.B.); (M.L.); (J.P.); (J.B.)
- St George Cancer Care Centre, Kogarah, NSW 2217, Australia
- School of Physics, University of Sydney, Camperdown, NSW 2050, Australia
| | - Joseph Bucci
- Centre for Medical Radiation Physics, University of Wollongong, Wollongong, NSW 2522, Australia; (T.N.H.B.); (M.L.); (J.P.); (J.B.)
- St George Cancer Care Centre, Kogarah, NSW 2217, Australia
| | - Edoardo Bianco
- Department of Electronics and Telecommunications, Polytechnic University of Turin, 10129 Turin, Italy; (E.B.); (R.A.G.)
- Istituto Nazionale di Fisica Nucleare—Section of Turin, 10125 Turin, Italy; (A.R.); (M.D.R.R.)
| | - Raffaele Aaron Giampaolo
- Department of Electronics and Telecommunications, Polytechnic University of Turin, 10129 Turin, Italy; (E.B.); (R.A.G.)
- Istituto Nazionale di Fisica Nucleare—Section of Turin, 10125 Turin, Italy; (A.R.); (M.D.R.R.)
| | - Angelo Rivetti
- Istituto Nazionale di Fisica Nucleare—Section of Turin, 10125 Turin, Italy; (A.R.); (M.D.R.R.)
| | - Manuel Da Rocha Rolo
- Istituto Nazionale di Fisica Nucleare—Section of Turin, 10125 Turin, Italy; (A.R.); (M.D.R.R.)
| | - Zeljko Pastuovic
- Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW 2234, Australia;
| | - Thomas Corradino
- Department of Industrial Engineering, University of Trento, 38123 Trento, Italy (L.P.)
- Trento Institute for Fundamental Physics and Applications, Istituto Nazionale di Fisica Nucleare, 38123 Trento, Italy
| | - Lucio Pancheri
- Department of Industrial Engineering, University of Trento, 38123 Trento, Italy (L.P.)
- Trento Institute for Fundamental Physics and Applications, Istituto Nazionale di Fisica Nucleare, 38123 Trento, Italy
| | - Marco Petasecca
- Centre for Medical Radiation Physics, University of Wollongong, Wollongong, NSW 2522, Australia; (T.N.H.B.); (M.L.); (J.P.); (J.B.)
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Petoukhova A, Snijder R, Vissers T, Ceha H, Struikmans H. In vivodosimetry in cancer patients undergoing intraoperative radiation therapy. Phys Med Biol 2023; 68:18TR01. [PMID: 37607566 DOI: 10.1088/1361-6560/acf2e4] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2022] [Accepted: 08/22/2023] [Indexed: 08/24/2023]
Abstract
In vivodosimetry (IVD) is an important tool in external beam radiotherapy (EBRT) to detect major errors by assessing differences between expected and delivered dose and to record the received dose by individual patients. Also, in intraoperative radiation therapy (IORT), IVD is highly relevant to register the delivered dose. This is especially relevant in low-risk breast cancer patients since a high dose of IORT is delivered in a single fraction. In contrast to EBRT, online treatment planning based on intraoperative imaging is only under development for IORT. Up to date, two commercial treatment planning systems proposed intraoperative ultrasound or in-room cone-beam CT for real-time IORT planning. This makes IVD even more important because of the possibility for real-time treatment adaptation. Here, we summarize recent developments and applications of IVD methods for IORT in clinical practice, highlighting important contributions and identifying specific challenges such as a treatment planning system for IORT. HDR brachytherapy as a delivery technique was not considered. We add IVD for ultrahigh dose rate (FLASH) radiotherapy that promises to improve the treatment efficacy, when compared to conventional radiotherapy by limiting the rate of toxicity while maintaining similar tumour control probabilities. To date, FLASH IORT is not yet in clinical use.
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Affiliation(s)
- Anna Petoukhova
- Haaglanden Medical Centre , Department of Medical Physics, Leidschendam, The Netherlands
| | - Roland Snijder
- Haaglanden Medical Centre , Department of Medical Physics, Leidschendam, The Netherlands
| | - Thomas Vissers
- Haaglanden Medical Centre , Medical Library, Leidschendam, The Netherlands
| | - Heleen Ceha
- Haaglanden Medical Centre , Department of Radiation Oncology, Leidschendam, The Netherlands
| | - Henk Struikmans
- Haaglanden Medical Centre , Department of Radiation Oncology, Leidschendam, The Netherlands
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Manna F, Pugliese M, Buonanno F, Gherardi F, Iannacone E, La Verde G, Muto P, Arrichiello C. Use of Thermoluminescence Dosimetry for QA in High-Dose-Rate Skin Surface Brachytherapy with Custom-Flap Applicator. SENSORS (BASEL, SWITZERLAND) 2023; 23:3592. [PMID: 37050652 PMCID: PMC10098582 DOI: 10.3390/s23073592] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Revised: 03/23/2023] [Accepted: 03/24/2023] [Indexed: 06/19/2023]
Abstract
Surface brachytherapy (BT) lacks standard quality assurance (QA) protocols. Commercially available treatment planning systems (TPSs) are based on a dose calculation formalism that assumes the patient is made of water, resulting in potential deviations between planned and delivered doses. Here, a method for treatment plan verification for skin surface BT is reported. Chips of thermoluminescent dosimeters (TLDs) were used for dose point measurements. High-dose-rate treatments were simulated and delivered through a custom-flap applicator provided with four fixed catheters to guide the Iridium-192 (Ir-192) source by way of a remote afterloading system. A flat water-equivalent phantom was used to simulate patient skin. Elekta TPS Oncentra Brachy was used for planning. TLDs were calibrated to Ir-192 through an indirect method of linear interpolation between calibration factors (CFs) measured for 250 kV X-rays, Cesium-137, and Cobalt-60. Subsequently, plans were designed and delivered to test the reproducibility of the irradiation set-up and to make comparisons between planned and delivered dose. The obtained CF for Ir-192 was (4.96 ± 0.25) μC/Gy. Deviations between measured and TPS calculated doses for multi-catheter treatment configuration ranged from -8.4% to 13.3% with an average of 0.6%. TLDs could be included in clinical practice for QA in skin BT with a customized flap applicator.
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Affiliation(s)
- Francesco Manna
- Department of Physics “E. Pancini”, Federico II University, 80126 Naples, Italy
- Centro Servizi Metrologici e Tecnologici Avanzati, Federico II University, 80146 Naples, Italy
| | - Mariagabriella Pugliese
- Department of Physics “E. Pancini”, Federico II University, 80126 Naples, Italy
- National Institute of Nuclear Physics, Section of Naples, 80126 Naples, Italy
| | - Francesca Buonanno
- Radiotherapy Unit, Istituto Nazionale Tumori, Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS), Fondazione G. Pascale, 80131 Naples, Italy
| | - Federica Gherardi
- Radiotherapy Unit, Istituto Nazionale Tumori, Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS), Fondazione G. Pascale, 80131 Naples, Italy
| | - Eva Iannacone
- Radiotherapy Unit, Istituto Nazionale Tumori, Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS), Fondazione G. Pascale, 80131 Naples, Italy
| | - Giuseppe La Verde
- Department of Physics “E. Pancini”, Federico II University, 80126 Naples, Italy
- National Institute of Nuclear Physics, Section of Naples, 80126 Naples, Italy
| | - Paolo Muto
- Radiotherapy Unit, Istituto Nazionale Tumori, Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS), Fondazione G. Pascale, 80131 Naples, Italy
| | - Cecilia Arrichiello
- Radiotherapy Unit, Istituto Nazionale Tumori, Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS), Fondazione G. Pascale, 80131 Naples, Italy
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van Wagenberg T, Fonseca GP, Voncken R, van Beveren C, van Limbergen E, Lutgens L, Vanneste BGL, Berbee M, Reniers B, Verhaegen F. Treatment verification in high dose rate brachytherapy using a realistic 3D printed head phantom and an imaging panel. Brachytherapy 2023; 22:269-278. [PMID: 36631373 DOI: 10.1016/j.brachy.2022.11.012] [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: 06/15/2022] [Revised: 10/24/2022] [Accepted: 11/26/2022] [Indexed: 01/11/2023]
Abstract
PURPOSE Even though High Dose Rate (HDR) brachytherapy has good treatment outcomes in different treatment sites, treatment verification is far from widely implemented because of a lack of easily available solutions. Previously it has been shown that an imaging panel (IP) near the patient can be used to determine treatment parameters such as the dwell time and source positions in a single material pelvic phantom. In this study we will use a heterogeneous head phantom to test this IP approach, and simulate common treatment errors to assess the sensitivity and specificity of the error-detecting capabilities of the IP. METHODS AND MATERIALS A heterogeneous head-phantom consisting of soft tissue and bone equivalent materials was 3D-printed to simulate a base of tongue treatment. An High Dose Rate treatment plan with 3 different catheters was used to simulate a treatment delivery, using dwell times ranging from 0.3 s to 4 s and inter-dwell distances of 2 mm. The IP was used to measure dwell times, positions and detect simulated errors. Measured dwell times and positions were used to calculate the delivered dose. RESULTS Dwell times could be determined within 0.1 s. Source positions were measured with submillimeter accuracy in the plane of the IP, and average distance accuracy of 1.7 mm in three dimensions. All simulated treatment errors (catheter swap, catheter shift, afterloader errors) were detected. Dose calculations show slightly different distributions with the measured dwell positions and dwell times (gamma pass rate for 1 mm/1% of 96.5%). CONCLUSIONS Using an IP, it was possible to verify the treatment in a realistic heterogeneous phantom and detect certain treatment errors.
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Affiliation(s)
- Teun van Wagenberg
- Department of Radiation Oncology (Maastro), GROW School for Oncology and Reproduction, Maastricht University Medical Centre+, Maastricht, The Netherlands
| | - Gabriel Paiva Fonseca
- Department of Radiation Oncology (Maastro), GROW School for Oncology and Reproduction, Maastricht University Medical Centre+, Maastricht, The Netherlands
| | - Robert Voncken
- Department of Radiation Oncology (Maastro), GROW School for Oncology and Reproduction, Maastricht University Medical Centre+, Maastricht, The Netherlands
| | - Celine van Beveren
- Department of Radiation Oncology (Maastro), GROW School for Oncology and Reproduction, Maastricht University Medical Centre+, Maastricht, The Netherlands
| | - Evert van Limbergen
- Department of Radiation Oncology (Maastro), GROW School for Oncology and Reproduction, Maastricht University Medical Centre+, Maastricht, The Netherlands
| | - Ludy Lutgens
- Department of Radiation Oncology (Maastro), GROW School for Oncology and Reproduction, Maastricht University Medical Centre+, Maastricht, The Netherlands
| | - Ben G L Vanneste
- Department of Radiation Oncology (Maastro), GROW School for Oncology and Reproduction, Maastricht University Medical Centre+, Maastricht, The Netherlands; Department of Human Structure and Repair; Department of Radiation Oncology, Ghent University Hospital, Gent, Belgium
| | - Maaike Berbee
- Department of Radiation Oncology (Maastro), GROW School for Oncology and Reproduction, Maastricht University Medical Centre+, Maastricht, The Netherlands
| | - Brigitte Reniers
- Research group NuTeC, Centre for Environmental Sciences, Hasselt University, Diepenbeek, Belgium
| | - Frank Verhaegen
- Department of Radiation Oncology (Maastro), GROW School for Oncology and Reproduction, Maastricht University Medical Centre+, Maastricht, The Netherlands.
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Gonod M, Suarez MA, Chacon Avila C, Karakhanyan V, Eustache C, Crouzilles J, Laskri S, Vinchant JF, Aubignac L, Grosjean T. Characterization of a miniaturized scintillator detector for time-resolved treatment monitoring in HDR-brachytherapy. Phys Med Biol 2022; 67. [PMID: 36240766 DOI: 10.1088/1361-6560/ac9a9b] [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: 07/13/2022] [Accepted: 10/14/2022] [Indexed: 11/06/2022]
Abstract
Purpose.HDR brachytherapy combines steep dose gradients in space and time, thereby requiring detectors of high spatial and temporal resolution to perform accurate treatment monitoring. We demonstrate a miniaturized fiber-integrated scintillator detector (MSD) of unmatched compactness which fulfills these conditions.Methods.The MSD consists of a 0.28 mm large and 0.43 mm long detection cell (Gd2O2S:Tb) coupled to a 110 micron outer diameter silica optical fiber. The fiber probe is tested in a phantom using a MicroSelectron 9.1 Ci Ir-192 HDR afterloader. The detection signal is acquired at a rate of 0.08 s with a standard sCMOS camera coupled to a chromatic filter (to cancel spurious Cerenkov signal). The dwell position and time monitoring are analyzed over prostate treatment sequences with dwell times spanning from 0.1 to 11 s. The dose rate at the probe position is both evaluated from a direct measurement and by reconstruction from the measured dwell position using the AAPM TG-43 formalism.Results.A total number of 1384 dwell positions are analyzed. In average, the measured dwell positions differ by 0.023 ± 0.077 mm from planned values over a 6-54 mm source-probe distance range. The standard deviation of the measured dwell positions is below 0.8 mm. 94% of the 966 dwell positions occurring at a source-probe inter-catheter spacing below 20 mm are successfully identified, with a 100% detection rate for dwell times exceeding 0.5 s. The average deviation to the planned dwell times is of 0.005 ± 0.060 s. The instant dose retrieval from dwell position monitoring leads to a relative mismatch to planned values of 0.14% ± 0.7%.Conclusion.A miniaturized Gd2O2S:Tb detector coupled to a standard sCMOS camera can be used for time-resolved treatment monitoring in HDR Brachytherapy.
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Affiliation(s)
- Mathieu Gonod
- Centre Georges François Leclerc (CGFL)-Dijon, France
| | - Miguel Angel Suarez
- FEMTO-ST Institute-Optics Department-UMR 6174-University of Franche-Comté-CNRS-Besançon, France
| | - Carlos Chacon Avila
- FEMTO-ST Institute-Optics Department-UMR 6174-University of Franche-Comté-CNRS-Besançon, France
| | - Vage Karakhanyan
- FEMTO-ST Institute-Optics Department-UMR 6174-University of Franche-Comté-CNRS-Besançon, France
| | - Clément Eustache
- FEMTO-ST Institute-Optics Department-UMR 6174-University of Franche-Comté-CNRS-Besançon, France
| | - Julien Crouzilles
- SEDI-ATI Fibres Optiques, 8 Rue Jean Mermoz, F-91080 Évry-Courcouronnes, France
| | - Samir Laskri
- SEDI-ATI Fibres Optiques, 8 Rue Jean Mermoz, F-91080 Évry-Courcouronnes, France
| | | | | | - Thierry Grosjean
- FEMTO-ST Institute-Optics Department-UMR 6174-University of Franche-Comté-CNRS-Besançon, France
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9
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Melhus CS, Simiele SJ, Aima M, Richardson S. Learning from the past: a century of accuracy, aspirations, and aspersions in brachytherapy. Br J Radiol 2022; 95:20220500. [PMID: 35969474 PMCID: PMC9733622 DOI: 10.1259/bjr.20220500] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Revised: 07/19/2022] [Accepted: 07/25/2022] [Indexed: 11/05/2022] Open
Abstract
The oldest form of radiation therapy, brachytherapy, has been investigated and reported in the scientific and medical literature for well over a century. Known by many names over the years, radium-based, empirical practices evolved over decades to contemporary practice. This includes treatment at various dose rates using multiple radionuclides or even electrically generated photon sources. Predictions or prognostications of what may happen in the future enjoy a history that spans centuries, e.g. those by Nostradamus in the 1500s. In this review article, publications from several eras of past practice between the early 1900s and the late 2010s where the authors address the "future of brachytherapy" are presented, and for many of these publications, one can use the benefit of the intervening years to comment on the accuracy or the inaccuracies inherent in those publications. Finally, recently published papers are reviewed to examine current expectations for the future practice of brachytherapy.
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Affiliation(s)
- Christopher S Melhus
- Department of Radiation Oncology, Tufts University School of Medicine, Boston, Massachusetts
| | - Samantha J Simiele
- Department of Radiation Physics, University of Texas MD Anderson Cancer Center, Houston, TX, United States
| | - Manik Aima
- Department of Radiation Oncology, Stanford University, Stanford, California, United States
| | - Susan Richardson
- Department of Radiation Oncology, Swedish Medical Center, Seattle, Washington, United States
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10
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Tachibana H, Watanabe Y, Kurokawa S, Maeyama T, Hiroki T, Ikoma H, Hirashima H, Kojima H, Shiinoki T, Tanimoto Y, Shimizu H, Shishido H, Oka Y, Hirose TA, Kinjo M, Morozumi T, Kurooka M, Suzuki H, Saito T, Fujita K, Shirata R, Inada R, Yada R, Yamashita M, Kondo K, Hanada T, Takenaka T, Usui K, Okamoto H, Asakura H, Notake R, Kojima T, Kumazaki Y, Hatanaka S, Kikumura R, Nakajima M, Nakada R, Suzuki R, Mizuno H, Kawamura S, Nakamura M, Akimoto T. Multi-Institutional Study of End-to-End Dose Delivery Quality Assurance Testing for Image-Guided Brachytherapy Using a Gel Dosimeter. Brachytherapy 2022; 21:956-967. [PMID: 35902335 DOI: 10.1016/j.brachy.2022.06.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Revised: 06/15/2022] [Accepted: 06/19/2022] [Indexed: 12/14/2022]
Abstract
PURPOSE To quantify dose delivery errors for high-dose-rate image-guided brachytherapy (HDR-IGBT) using an independent end-to-end dose delivery quality assurance test at multiple institutions. The novelty of our study is that this is the first multi-institutional end-to-end dose delivery study in the world. MATERIALS AND METHODS The postal audit used a polymer gel dosimeter in a cylindrical acrylic container for the afterloading system. Image acquisition using computed tomography, treatment planning, and irradiation were performed at each institution. Dose distribution comparison between the plan and gel measurement was performed. The percentage of pixels satisfying the absolute-dose gamma criterion was reviewed. RESULTS Thirty-five institutions participated in this study. The dose uncertainty was 3.6% ± 2.3% (mean ± 1.96σ). The geometric uncertainty with a coverage factor of k = 2 was 3.5 mm. The tolerance level was set to the gamma passing rate of 95% with the agreement criterion of 5% (global)/3 mm, which was determined from the uncertainty estimation. The percentage of pixels satisfying the gamma criterion was 90.4% ± 32.2% (mean ± 1.96σ). Sixty-six percent (23/35) of the institutions passed the verification. Of the institutions that failed the verification, 75% (9/12) had incorrect inputs of the offset between the catheter tip and indexer length in treatment planning and 17% (2/12) had incorrect catheter reconstruction in treatment planning. CONCLUSIONS The methodology should be useful for comprehensively checking the accuracy of HDR-IGBT dose delivery and credentialing clinical studies. The results of our study highlight the high risk of large source positional errors while delivering dose for HDR-IGBT in clinical practices.
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Affiliation(s)
- Hidenobu Tachibana
- Radiation Safety and Quality Assurance division, National Cancer Center Hospital East, Kashiwa, Chiba, Japan.
| | - Yusuke Watanabe
- School of Allied Health Sciences, Kitasato University, Sagamihara, Kanagawa, Japan
| | - Shogo Kurokawa
- Radiation Safety and Quality Assurance division, National Cancer Center Hospital East, Kashiwa, Chiba, Japan
| | - Takuya Maeyama
- School of Science, Kitasato University, Sagamihara, Kanagawa, Japan
| | - Tomoyuki Hiroki
- Department of Radiology, Tokai University Hospital, Isehara, Kanagawa, Japan
| | - Hideaki Ikoma
- Department of Radiation Technology, Ibaraki Prefectual Central Hospital, Kasama, Ibaraki, Japan
| | - Hideaki Hirashima
- Deparment of Radiation Oncology and Image-Applied Therapy, Graduate School of Medicine, Kyoto University, Kyoto, Kyoto, Japan
| | - Hironori Kojima
- Department of Radiology, Kanazawa University Hospital, Kanazawa, Ishikawa, Japan
| | - Takehiro Shiinoki
- Department of Radiation Oncology, Yamaguchi University Graduate School of Medicine, Ube, Yamaguchi, Japan
| | - Yuuki Tanimoto
- Department of Radiology, Shikoku Cancer Center, Matsuyama, Ehime, Japan
| | - Hidetoshi Shimizu
- Department of Radiation Oncology, Aichi Cancer Center Hospital, Nagoya, Aichi, Japan
| | - Hiroki Shishido
- Division of Radiology and Nuclear Medicine, Sapporo Medical University Hospital, Sapporo, Hokkaido, Japan
| | - Yoshitaka Oka
- Department of Radiology, Fukushima Medical University Hospital, Fukushima, Fukushima, Japan
| | - Taka-Aki Hirose
- Division of Radiology, Department of Medical Technology, Kyushu University Hospital, Fukuoka, Fukuoka, Japan
| | - Masashi Kinjo
- Department of Radiology, University of the Ryukyus Graduate School of Medical Science, Nishihara, Okinawa, Japan
| | - Takuya Morozumi
- Department of Radiology, Nagano Municipal Hospital, Nagano, Nagano, Japan
| | - Masahiko Kurooka
- Department of Radiation Therapy, Tokyo Medical University Hospital, Shinjuku, Tokyo, Japan
| | - Hidekazu Suzuki
- Department of Radiology, University of Yamanashi Hospital, Chuo, Yamanashi, Japan
| | - Tomohiko Saito
- Central Division of Radiology, Akita University Hospital, Akita, Akita, Japan
| | - Keiichi Fujita
- Department of Radiology, Asahi General Hospital, Asahi, Chiba, Japan
| | - Ryosuke Shirata
- Department of Radiation Oncology, Shonan Kamakura General Hospital, Kamakura, Kanagawa, Japan
| | - Ryuji Inada
- Department of Radiology, Kitasato University Hospital, Sagamihara, Kanagawa, Japan
| | - Ryuichi Yada
- Division of Radiation Oncology, Kobe University Graduate School of Medicine, Kobe, Hyogo, Japan
| | - Mikiko Yamashita
- Department of Radiological Technology, Kobe City Medical Center General Hospital, Kobe, Hyogo, Japan
| | - Kazuto Kondo
- Department of Radiological Technology, Kurashiki Central Hospital, Kurashiki, Okayama, Japan
| | - Takashi Hanada
- Department of Radiology, Keio University School of Medicine, Shinjuku, Tokyo, Japan
| | - Tadashi Takenaka
- Department of Radiology, Kyoto Prefectural University of Medicine, Kyoto, Kyoto, Japan
| | - Keisuke Usui
- Department of Radiological Technology, Juntendo University, Faculty of Health Science, Bunkyo, Tokyo, Japan
| | - Hiroyuki Okamoto
- Radiation Safety and Quality Assurance Division, National Cancer Center Hospital, Chuo, Tokyo, Japan
| | - Hiroshi Asakura
- Radiation Oncology Center, Dokkyo Medical University Hospital, Shimotsuga, Tochigi, Japan
| | - Ryoichi Notake
- Department of Radiology, Tokyo Medical And Dental University, Medical Hospital, Bunkyo, Tokyo, Japan
| | - Toru Kojima
- Department of Radiation Oncology, Saitama Cancer Center, Ina, Saitama, Japan
| | - Yu Kumazaki
- Department of Radiation Oncology, Saitama Medical University International Medical Center, Hidaka, Saitama, Japan
| | - Shogo Hatanaka
- Department of Radiation Oncology, Saitama Medical Center, Saitama Medical University, Kawagoe, Saitama, Japan
| | - Riki Kikumura
- Department of Radiology, National Hospital Organization, Tokyo Medical Center, Meguro, Tokyo, Japan
| | - Masaru Nakajima
- Department of Radiation Oncology, The Cancer Institute Hospital Of JFCR, Koto, Tokyo, Japan
| | - Ryosei Nakada
- Radiation and Proton Therapy Center, Shizuoka Cancer Center, Nagaizumi, Shizuoka, Japan
| | - Ryusuke Suzuki
- Department of Medical physics, Hokkaido University Hospital, Sapporo, Hokkaido, Japan
| | - Hideyuki Mizuno
- Quality control section, QST hospital, National Institutes for Quantum Science and Technology, Chiba, Chiba, Japan
| | - Shinji Kawamura
- Division of Radiological Sciences, Teikyo University Graduate School of Health Sciences, Omuta, Fukuoka, Japan
| | - Mistuhiro Nakamura
- Division of Medical Physics, Human Health Sciences, Graduate School of Medicine, Kyoto University, Kyoto, Kyoto, Japan
| | - Tetsuo Akimoto
- Department of Radiation Oncology, National Cancer Center Hospital East, Kashiwa, Chiba, Japan
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11
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Optimization of the energy window setting in Ir-192 source imaging for high-dose-rate brachytherapy using a YAP(Ce) gamma camera. Phys Med 2022; 103:66-73. [DOI: 10.1016/j.ejmp.2022.09.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Revised: 09/27/2022] [Accepted: 09/28/2022] [Indexed: 11/19/2022] Open
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12
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In Vivo Dosimetry for Superficial High Dose Rate Brachytherapy with Optically Stimulated Luminescence Dosimeters: A Comparison Study with Metal-Oxide-Semiconductor Field-Effect Transistors. RADIATION 2022. [DOI: 10.3390/radiation2040026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
The purpose of the study was to calibrate and commission optically-stimulated luminescence dosimeters (OSLDs) for in vivo measurements in contact-based 192Ir treatments for superficial high dose rate (HDR) brachytherapy in place of metal-oxide-semiconductor field-effect transistors (MOSFETs). Dose linearity and dose rate dependence were tested by varying source-to-OSLD distance and dwell time. Angular dependence was measured using a solid water phantom setup for OSLD rotation. A group of OSLDs were readout 34 consecutive times to test readout depletion while OSLDs were optically annealed using a mercury lamp for 34.7 h. End-to-end tests were performed using a Freiburg flap and Valencia applicator. OSLD measurements were compared to MOSFETs and treatment planning system (TPS) doses. OSLD response was supralinear for doses above 275 cGy. They were found to be independent of dose rate and dependent on the incident angle in edge-on scenarios. OSLDs exhibited minimal readout depletion and were successfully annealed after 24 h of illumination. Freiburg flap measurements agreed well with the TPS. For the Valencia, OSLDs showed to be the more accurate system over MOSFETs, with a maximum disagreement with the TPS being 0.09%. As such, OSLDs can successfully be used in place of MOSFETs for in vivo dosimetry for superficial HDR brachytherapy.
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13
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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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14
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Jaberi R, Babaloui S, Siavashpour Z, Moshtaghi M, Shirazi A, Joya M, Gholami MH, Jafari S. 3D in vivo dosimetry of HDR gynecological brachytherapy using micro silica bead TLDs. J Appl Clin Med Phys 2022; 23:e13729. [PMID: 35946855 PMCID: PMC9512342 DOI: 10.1002/acm2.13729] [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: 04/26/2022] [Revised: 06/30/2022] [Accepted: 07/01/2022] [Indexed: 11/26/2022] Open
Abstract
Purpose This study aimed to evaluate the feasibility of defining an in vivo dosimetry (IVD) protocol as a patient‐specific quality assurance (PSQA) using the bead thermoluminescent dosimeters (TLDs) for point and 3D IVD during brachytherapy (BT) of gynecological (GYN) cancer using 60Co high‐dose‐rate (HDR) source. Methods The 3D in vivo absorbed dose verification within the rectum and bladder as organs‐at‐risk was performed by bead TLDs for 30 GYN cancer patients. For rectal wall dosimetry, 80 TLDs were placed in axial arrangements around a rectal tube covered with a layer of gel. Ten beads were placed inside the Foley catheter to get the bladder‐absorbed dose. Beads TLDs were localized and defined as control points in the treatment planning system (TPS) using CT images of the patients. Patients were planned and treated using the routine BT protocol. The experimentally obtained absorbed dose map of the rectal wall and the point dose of the bladder were compared to the TPSs predicted absorbed dose at these control points. Results Relative difference between TPS and TLDs results were −8.3% ± 19.5% and −7.2% ± 14.6% (1SD) for rectum‐ and bladder‐absorbed dose, respectively. Gamma analysis was used to compare the calculated with the measured absorbed dose maps. Mean gamma passing rates of 84.1%, 90.8%, and 92.5% using the criteria of 3%/2 mm, 3%/3 mm, and 4%/2 mm were obtained, respectively. Eventually, a “considering level” of at least 85% as pass rate with 4%/2‐mm criteria was recommended. Conclusions A 3D IVD protocol employing bead TLDs was presented to measure absorbed doses delivered to the rectum and bladder during GYN HDR‐BT as a reliable PSQA method. 3D rectal absorbed dose measurements were performed. Differences between experimentally measured and planned absorbed dose maps were presented in the form of a gamma index, which may be used as a warning for corrective action.
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Affiliation(s)
- Ramin Jaberi
- Radiation Oncology Department, Yas Hospital Complex, Tehran University of Medical Sciences, Tehran, Iran.,Department of Physics, University of Surrey, Guildford, UK
| | - Somayyeh Babaloui
- Department of Medical Physics and Biomedical Engineering, Faculty of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Zahra Siavashpour
- Radiotherapy Oncology Department, Shohada-e-Tajrish Educational Hospital, Medical School, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Maryam Moshtaghi
- Radiation Oncology Department, Yas Hospital Complex, Tehran University of Medical Sciences, Tehran, Iran
| | - Alireza Shirazi
- Department of Medical Physics and Biomedical Engineering, Faculty of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Musa Joya
- Department of Medical Physics and Biomedical Engineering, Faculty of Medicine, Tehran University of Medical Sciences, Tehran, Iran.,Radiology Department, Kabul University of Medical Sciences, Afghanistan
| | - Mohammad Hadi Gholami
- Department of Medical Radiation Engineering, Science and Research Branch, Islamic Azad University, Tehran, Iran.,Mahdieh Radiotherapy Oncology Center, Hamedan, Iran
| | - Shakardokht Jafari
- Department of Physics, University of Surrey, Guildford, UK.,Medical Physics Dept., Portsmouth Hospitals University NHS Trust, Portsmouth, UK.,Medical Research Centre, Kateb University, Kabul, Afghanistan
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15
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Masterson M, Wood-stott G, Jafari SM, Bradley D. A review of micro silica beads in radiation dosimetry applications. Radiat Phys Chem Oxf Engl 1993 2022. [DOI: 10.1016/j.radphyschem.2022.110367] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
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16
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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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17
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Dosimetry procedure to verify dose in High Dose Rate (HDR) brachytherapy treatment of cancer patients: A systematic review. Phys Med 2022; 96:70-80. [DOI: 10.1016/j.ejmp.2022.02.022] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Revised: 02/18/2022] [Accepted: 02/21/2022] [Indexed: 01/12/2023] Open
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18
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Using micro silica bead TLDs in high dose rate brachytherapy dosimetry: A phantom study. Radiat Phys Chem Oxf Engl 1993 2022. [DOI: 10.1016/j.radphyschem.2021.109826] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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19
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Hayashi H, Kimoto N, Maeda T, Tomita E, Asahara T, Goto S, Kanazawa Y, Shitakubo Y, Sakuragawa K, Ikushima H, Okazaki T, Hashizume T. A disposable OSL dosimeter for in vivo measurement of rectum dose during brachytherapy. Med Phys 2021; 48:4621-4635. [PMID: 33760234 DOI: 10.1002/mp.14857] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Revised: 02/26/2021] [Accepted: 03/15/2021] [Indexed: 12/31/2022] Open
Abstract
PURPOSE We aimed to develop a disposable rectum dosimeter and to demonstrate its ability to measure exposure dose to the rectum during brachytherapy for cervical cancer treatment using high-dose rate 192 Ir. Our rectum dosimeter measures the dose with an optically stimulated luminescence (OSL) sheet which was furled to a catheter. The catheter we used is 6 mm in diameter; therefore, it is much less invasive than other rectum dosimeters. The rectum dosimeter developed in this study has the characteristics of being inexpensive and disposable. It is also an easy-to-use detector that can be individually sterilized, making it suitable for clinical use. METHODS To obtain a dose calibration curve, phantom experiments were performed. Irradiation was performed using a cubical acrylic phantom, and the response of the OSL dosimeter was calibrated with the calculation value predicted by the treatment planning system (TPS). Additionally, the dependence of catheter angle on the dosimeter position and repeatability were evaluated. We also measured the absorbed dose to the rectum of patients who were undergoing brachytherapy for cervical cancer (n = 64). The doses measured with our dosimeters were compared with the doses calculated by the TPS. In order to examine the causes of large differences between measured and planned doses, we classified the data into common and specific cases when performing this clinical study. For specific cases, the following three categories were considered: (a) patient movement, (b) gas in the vagina and/or rectum, and (c) artifacts in the X-ray image caused by applicators. RESULTS A dose calibration curve was obtained in the range of 0.1 Gy-10.0 Gy. From the evaluation of the dependence of catheter angle on the dosimeter position and repeatability, we determined that our dosimeter can measure rectum dose with an accuracy of 3.1% (k = 1). In this clinical study, we succeeded in measuring actual doses using our rectum dosimeter. We found that the deviation of the measured dose from the planned dose was derived to be 12.7% (k = 1); this result shows that the clinical study included large elements of uncertainty. The discrepancies were found to be due to patient motion during treatment, applicator movement after planning images were taken, and artifacts in the planning images. CONCLUSIONS We present the idea that a minimally invasive rectum dosimeter can be fabricated using an OSL sheet. Our clinical study demonstrates that a rectum dosimeter made from an OSL sheet has sufficient ability to evaluate rectum dose. Using this dosimeter, valuable information concerning organs at risk can be obtained during brachytherapy.
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Affiliation(s)
- Hiroaki Hayashi
- College of Medical, Pharmaceutical and Health Sciences, Kanazawa University, Kanazawa, Ishikawa, Japan
| | - Natsumi Kimoto
- Graduate School of Medical Sciences, Kanazawa University, Kanazawa, Ishikawa, Japan
| | - Tatsuya Maeda
- Graduate School of Medical Sciences, Kanazawa University, Kanazawa, Ishikawa, Japan
| | - Emi Tomita
- Graduate School of Medical Sciences, Kanazawa University, Kanazawa, Ishikawa, Japan
| | - Takashi Asahara
- Graduate School of Medical Sciences, Kanazawa University, Kanazawa, Ishikawa, Japan.,Okayama University Hospital, Kitaku, Okayama, Japan
| | - Sota Goto
- Graduate School of Medical Sciences, Kanazawa University, Kanazawa, Ishikawa, Japan
| | - Yuki Kanazawa
- Graduate School of Health Sciences, Tokushima University, Tokushima, Japan
| | | | | | - Hitoshi Ikushima
- Graduate School of Health Sciences, Tokushima University, Tokushima, Japan.,Tokushima University Hospital, Tokushima, Japan
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20
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Evaluation of exit skin dose for intra-cavitary brachytherapy treatments by the BEBIG 60Co machine using thermoluminescent dosimeters. JOURNAL OF RADIOTHERAPY IN PRACTICE 2021. [DOI: 10.1017/s1460396919001018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
AbstractPurpose:This study aims to evaluate the application of the exit skin dose (ESD) in verifying the accuracy of intra-cavitary brachytherapy treatments performed by the BEBIG 60Co machine using thermoluminescent dosimeters (TLDs).Materials and methods:Eleven patients who were treated for gynaecological (GYN) malignancy by high-dose-rate (HDR) brachytherapy machine have been considered in this study. A combination of tandem, cylinder and interstitial needles was applied for eight patients while tandem ovoid (TO) applicators were used for the rest (three patients). In order to measure ESD, thermoluminescent dosimetry was performed for each patient. TLDs were placed precisely on the patient’s skin along her symphysis pubis bone (anterior) and left (L)/right (R) sides of her pelvic. Positioning of the dosimeter was accurately determined using fiducial markers in computed tomography (CT) scan imaging, prior to the treatment. Finally, a comparison was made between the calculated dose from the treatment planning system (TPS) and the dose measured by TLDs.Results:About 90% of all cases showed a good agreement (while considering TLD uncertainty ∼5·5%) between TPS dose calculations and TLD measurements. The measured mean values of ESD received to anterior, left and right positions were 56·72, 12·18 and 12·82 cGy, respectively. For three patients, differences up to 11·9% were detected.Conclusion:To conclude, ESD measurement method can be a suitable practical approach for verifying the accuracy of GYN HDR treatment delivery.
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21
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Dose assessment in high dose rate brachytherapy with cobalt-60 source for cervical cancer treatment: a phantom study. POLISH JOURNAL OF MEDICAL PHYSICS AND ENGINEERING 2020. [DOI: 10.2478/pjmpe-2020-0029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Abstract
Transition from low dose rate brachytherapy to high dose rate brachytherapy at our department necessitated the performance of dose verification test, which served as an end-to-end quality assurance procedure to verify and validate dose delivery in intracavitary brachytherapy of the cervix and the vaginal walls based on the Manchester system. An in-house water phantom was designed and constructed from Perspex sheets to represent the cervix region of a standard adult patient. The phantom was used to verify the whole dose delivery chain such as calibration of the cobalt-60 source in use, applicator, and source localization method, the output of treatment planning with dedicated treatment planning system, and actual dose delivery process. Since the above factors would influence the final dose delivered, doses were measured with calibrated gafchromic EBT3 films at various points within the in-house phantom for a number of clinical implants that were used to treat a patient based on departmental protocol. The measured doses were compared to those of the treatment planning system. The discrepancies between measured doses and their corresponding calculated doses obtained with the treatment planning system ranged from -29.67 to 40.34% (mean of ±13.27%). These compared similarly to other studies.
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22
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Cusumano D, Placidi L, D'Agostino E, Boldrini L, Menna S, Valentini V, De Spirito M, Azario L. Characterization of an inorganic scintillator for small-field dosimetry in MR-guided radiotherapy. J Appl Clin Med Phys 2020; 21:244-251. [PMID: 32841500 PMCID: PMC7497936 DOI: 10.1002/acm2.13012] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2020] [Revised: 04/04/2020] [Accepted: 07/27/2020] [Indexed: 11/11/2022] Open
Abstract
INTRODUCTION Aim of this study is to dosimetrically characterize a new inorganic scintillator designed for magnetic resonance-guided radiotherapy (MRgRT) in the presence of 0.35 tesla magnetic field (B). METHODS The detector was characterized in terms of signal to noise ratio (SNR), reproducibility, dose linearity, angular response, and dependence by energy, field size, and B orientation using a 6 MV magnetic resonance (MR)-Linac and a water tank. Field size dependence was investigated by measuring the output factor (OF) at 1.5 cm. The results were compared with those measured using other detectors (ion chamber and synthetic diamond) and those calculated using a Monte Carlo (MC) algorithm. Energy dependence was investigated by acquiring a percentage depth dose (PDD) curve at two field sizes (3.32 × 3.32 and 9.96 × 9.96 cm2 ) and repeating the OF measurements at 5 and 10 cm depths. RESULTS The mean SNR was 116.3 ± 0.6. Detector repeatability was within 1%, angular dependence was <2% and its response variation based on the orientation with respect to the B lines was <1%. The detector has a temporal resolution of 10 Hz and it showed a linear response (R2 = 1) in the dose range investigated. All the OF values measured at 1.5 cm depth using the scintillator are in accordance within 1% with those measured with other detectors and are calculated using the MC algorithm. PDD values are in accordance with MC algorithm only for 3.32 × 3.32 cm2 field. Numerical models can be applied to compensate for energy dependence in case of larger fields. CONCLUSION The inorganic scintillator in the present form can represent a valuable detector for small-field dosimetry and periodic quality controls at MR-Linacs such as dose stability, OFs, and dose linearity. In particular, the detector can be effectively used for small-field dosimetry at 1.5 cm depth and for PDD measurements if the field dimension of 3.32 × 3.32 cm2 is not exceeded.
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Affiliation(s)
- Davide Cusumano
- Fondazione Policlinico Universitario A. Gemelli IRCCSRomeItaly
| | - Lorenzo Placidi
- Fondazione Policlinico Universitario A. Gemelli IRCCSRomeItaly
| | | | - Luca Boldrini
- Fondazione Policlinico Universitario A. Gemelli IRCCSRomeItaly
| | | | | | | | - Luigi Azario
- Fondazione Policlinico Universitario A. Gemelli IRCCSRomeItaly
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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: 6] [Impact Index Per Article: 1.5] [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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The impact of rectal/bladder filling and applicator positioning on in vivo rectal dosimetry in vaginal cuff brachytherapy using an enhanced therapy setting. Brachytherapy 2019; 19:168-175. [PMID: 31883803 DOI: 10.1016/j.brachy.2019.11.009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2019] [Revised: 11/19/2019] [Accepted: 11/23/2019] [Indexed: 12/15/2022]
Abstract
PURPOSE The impact of rectal filling and bladder volume on in vivo rectal dosimetry (IVD) in vaginal cuff brachytherapy (VCBT) is unknown. The purpose of this study was to compare rectal doses from IVD with those calculated from treatment planning and to identify influencing factors. MATERIALS AND METHODS We collected data of 80 VCBT sessions, four for each of 20 patients. Each was retrospectively compared with doses determined by the treatment planning system. Factors potentially predicting the IVD rectum dose were analyzed. RESULTS For a series of 80 brachytherapy applications, the calculated mean dose to the rectum was 2.52 Gy. The mean difference between all calculated and measured doses for the 80 applications with five probe positions each was 0.09 Gy (p = 0.952) proving high overall accordance between IVD and calculated doses at the rectum. The mean volume of the rectum was 119 ± 57 cm³. The rectal volume was not statistically significantly associated with the IVD or the calculated rectum doses. At the third and fourth rectal probe position in craniocaudal ordering, increased filling of the urinary bladder resulted in decreased measured and calculated doses (p < 0.05 for both). A rectum pointing position of the applicator significantly increased the maximum rectum dose compared with a bladder-oriented position (p < 0.05). CONCLUSIONS IVD provided valuable data for rectal exposure in VCBT. Increased bladder filling and vaginal applicator positioning off the rectum elicited related with less rectal radiation exposure, whereas rectal filling did not. Further confirmation including assessment of IVD in bladder is pending to define optimal dosimetric conditions in VCBT.
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Abstract
Many brachytherapy (BT) errors could be detected with real-time in vivo dosimetry technology. Inorganic scintillation detectors (ISDs) have demonstrated promising capabilities for BT, because some ISD materials can generate scintillation signals large enough that (a) the background signal emitted in the fiber-optic cable (stem signal) is insignificant, and (b) small detector volumes can be used to avoid volume averaging effects in steep dose gradients near BT sources. We investigated the characteristics of five ISD materials to identify one that is appropriate for BT. ISDs consisting of a 0.26 to 1.0 mm3 volume of ruby (Al2O3:Cr), a mixture of Y2O3:Eu and YVO4:Eu, ZnSe:O, or CsI:Tl coupled to a fiber-optic cable were irradiated in a water-equivalent phantom using a high-dose-rate 192Ir BT source. Detectors based on plastic scintillators BCF-12 and BCF-60 (0.8 mm3 volume) were used as a reference. Measurements demonstrated that the ruby, Y2O3:Eu+YVO4:Eu, ZnSe:O, and CsI:Tl ISDs emitted scintillation signals that were up to 19, 19, 250, and 880 times greater, respectively, than that of the BCF-12 detector. While the total signals of the plastic scintillation detectors were dominated by the stem signal for source positions 0.5 cm from the fiber-optic cable and >3.5 cm from the scintillator volume, the stem signal for the ruby and Y2O3:Eu+YVO4:Eu ISDs were <1% of the total signal for source positions <3.4 and <4.4 cm from the scintillator, respectively, and <0.7% and <0.5% for the ZnSe:O and CsI:Tl ISDs, respectively, for positions ⩽8.0 cm. In contrast to the other ISDs, the Y2O3:Eu+YVO4:Eu ISD exhibited unstable scintillation and significant afterglow. All ISDs exhibited significant energy dependence, i.e. their dose response to distance-dependent 192Ir energy spectra differed significantly from the absorbed dose in water. Provided that energy dependence is accounted for, ZnSe:O ISDs are promising for use in error detection and patient safety monitoring during BT.
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Affiliation(s)
- Gustavo Kertzscher
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, TX, United States of America
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Kallis K, Abu-Hossin N, Kreppner S, Lotter M, Strnad V, Fietkau R, Bert C. Estimation of inter-fractional variations in interstitial multi-catheter breast brachytherapy using a hybrid treatment delivery system. Radiother Oncol 2019; 141:312-320. [PMID: 31495517 DOI: 10.1016/j.radonc.2019.08.012] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2019] [Revised: 08/13/2019] [Accepted: 08/14/2019] [Indexed: 11/30/2022]
Abstract
PURPOSE Irradiation of the tumor bed using interstitial multi-catheter brachytherapy is one of the treatment options for breast cancer patients. In order to ensure the planned dose delivery an advanced quality intervention method using an electromagnetic tracking (EMT) system is presented. The system is used to assess inter-fractional variations within the framework of a patient study. METHODS AND MATERIALS Until now 41 patients were included in the study for the evaluation and overall 355 EMT measurements were performed. The catheter traces are measured automatically and sequentially using an afterloader prototype (Flexitron, Elekta, Veenendaal, The Netherlands) equipped with an EMT sensor. The implant geometry is tracked directly after implantation, after CT imaging and after each irradiation fraction. The acquired data is rigidly registered to the catheter traces defined in the treatment plan and the dwell positions (DP) are reconstructed. DPs defined in treatment planning serve as reference. Breathing motion was corrected and recorded using three reference 6DoF sensors placed on the patients' skin. The Euclidean distance between the planned and reconstructed DPs provides information about possible inter-fractional deviations. Further, the influence of various factors on the occurrence of large deviations was investigated, like the patients' age, the length of the catheter, the breast volume, etc. RESULTS: Over all patient measurements a median Euclidean distance of 2.19 mm was determined between the reconstructed DPs and the reference DPs. The median deviation combining all datasets was minimal (1.67 mm) at the measurement directly after CT imaging. The deviations between the different fractions have a median distance of 2.31 mm which could be improved to 2.05 mm by adapting the treatment plan according to the follow-up CT. No correlation between the distance to the skin, ribs, mammilla or the breast volume and the occurrences of large deviations was found. The largest deviations were determined in the upper inner quadrant of the breast. CONCLUSION The afterloader prototype could be well integrated into the clinical routine and is beneficial for ensuring the quality of the brachytherapy. Overall, a small median DP deviation, lower than the used step size of 2.5 mm, was detected.
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Affiliation(s)
- Karoline Kallis
- Department of Radiation Oncology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany.
| | - Nadin Abu-Hossin
- Department of Radiation Oncology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany
| | - Stephan Kreppner
- Department of Radiation Oncology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany
| | - Michael Lotter
- Department of Radiation Oncology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany
| | - Vratislav Strnad
- Department of Radiation Oncology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany
| | - Rainer Fietkau
- Department of Radiation Oncology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany
| | - Christoph Bert
- Department of Radiation Oncology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany.
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Poder J, Carrara M, Howie A, Cutajar D, Bucci J, Rosenfeld A. Derivation of in vivo source tracking error thresholds for TRUS-based HDR prostate brachytherapy through simulation of source positioning errors. Brachytherapy 2019; 18:711-719. [DOI: 10.1016/j.brachy.2019.05.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2019] [Revised: 04/23/2019] [Accepted: 05/03/2019] [Indexed: 10/26/2022]
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Yamamoto S, Yogo K, Noguchi Y, Nakaya T, Okudaira K. Imaging of Ir-192 source using a high energy gamma camera for high-dose-rate brachytherapy. RADIAT MEAS 2019. [DOI: 10.1016/j.radmeas.2019.106128] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Romanyukha A, Carrara M, Mazzeo D, Tenconi C, Al-Salmani T, Poder J, Cutajar D, Fuduli I, Petasecca M, Bucci J, Cerrotta A, Pappalardi B, Piccolo F, Pignoli E, Rosenfeld A. An innovative gynecological HDR brachytherapy applicator system for treatment delivery and real-time verification. Phys Med 2019; 59:151-157. [DOI: 10.1016/j.ejmp.2019.03.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/03/2018] [Revised: 02/27/2019] [Accepted: 03/01/2019] [Indexed: 10/27/2022] Open
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Richart J, Carmona-Meseguer V, García-Martínez T, Herreros A, Otal A, Pellejero S, Tornero-López A, Pérez-Calatayud J. Review of strategies for MRI based reconstruction of endocavitary and interstitial applicators in brachytherapy of cervical cancer. Rep Pract Oncol Radiother 2018; 23:547-561. [PMID: 30534019 PMCID: PMC6277512 DOI: 10.1016/j.rpor.2018.06.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2017] [Revised: 04/04/2018] [Accepted: 06/23/2018] [Indexed: 12/14/2022] Open
Abstract
Brachytherapy plays an essential role in the curative intent management of locally advanced cervical cancer. The introduction of the magnetic resonance (MR) as a preferred image modality and the development of new type of applicators with interstitial components have further improved its benefits. The aim of this work is to review the current status of one important aspect in the cervix cancer brachytherapy procedure, namely catheter reconstruction. MR compatible intracavitary and interstitial applicators are described. Considerations about the use of MR imaging (MRI) regarding appropriate strategies for applicator reconstruction, technical requirements, MR sequences, patient preparation and applicator commissioning are included. It is recommendable to perform the reconstruction process in the same image study employed by the physician for contouring, that is, T2 weighted (T2W) sequences. Nevertheless, a clear identification of the source path inside the catheters and the applicators is a challenge when using exclusively T2W sequences. For the intracavitary component of the implant, sometimes the catheters may be filled with some substance that produces a high intensity signal on MRI. However, this strategy is not feasible for plastic tubes or titanium needles, which, moreover, induce magnetic susceptibility artifacts. In these situations, the use of applicator libraries available in the treatment planning system (TPS) is useful, since they not only include accurate geometrical models of the intracavitary applicators, but also recent developments have made possible the implementation of the interstitial component. Another strategy to improve the reconstruction process is based on the incorporation of MR markers, such as small pellets, to be used as anchor points. Many institutions employ computed tomography (CT) as a supporting image modality. The registration of CT and MR image sets should be carefully performed, and its uncertainty previously assessed. Besides, an important research work is being carried out regarding the use of ultrasound and electromagnetic tracking technologies.
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Affiliation(s)
- José Richart
- Hospital Clínica Benidorm, Medical Physics Department, Alicante, Spain
| | - Vicente Carmona-Meseguer
- Hospital La Fe-IRIMED, Department of Radiation Oncology, Medical Physics Section, Valencia, Spain
| | | | - Antonio Herreros
- Hospital Clínic, Department of Radiation Oncology, Medical Physics Section, Barcelona, Spain
| | - Antonio Otal
- Hospital Arnau de Vilanova, Medical Physics Department, Lleida, Spain
| | - Santiago Pellejero
- Complejo Hospitalario de Navarra, Medical Physics Department, Pamplona, Spain
| | - Ana Tornero-López
- Hospital Dr. Negrín, Medical Physics Department, Las Palmas de Gran Canaria, Spain
| | - José Pérez-Calatayud
- Hospital La Fe-IRIMED, Department of Radiation Oncology, Medical Physics Section, Valencia, Spain
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31
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Beld E, Seevinck PR, Schuurman J, Viergever MA, Lagendijk JJ, Moerland MA. Development and Testing of a Magnetic Resonance (MR) Conditional Afterloader for Source Tracking in Magnetic Resonance Imaging-Guided High-Dose-Rate (HDR) Brachytherapy. Int J Radiat Oncol Biol Phys 2018; 102:960-968. [DOI: 10.1016/j.ijrobp.2018.04.066] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2017] [Revised: 03/13/2018] [Accepted: 04/24/2018] [Indexed: 01/18/2023]
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32
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Belley MD, Craciunescu O, Chang Z, Langloss BW, Stanton IN, Yoshizumi TT, Therien MJ, Chino JP. Real-time dose-rate monitoring with gynecologic brachytherapy: Results of an initial clinical trial. Brachytherapy 2018; 17:1023-1029. [DOI: 10.1016/j.brachy.2018.07.014] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2017] [Revised: 06/10/2018] [Accepted: 07/16/2018] [Indexed: 12/25/2022]
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Pittet P, Jalade P, Gindraux L, Guiral P, Wang R, Galvan JM, Lu GN. DoRGaN: Development of Quality Assurance and Quality Control Systems for High Dose Rate Brachytherapy Based on GaN Dosimetry Probes. Ing Rech Biomed 2018. [DOI: 10.1016/j.irbm.2018.04.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Haie-Méder C, Maroun P, Fumagalli I, Lazarescu I, Dumas I, Martinetti F, Chargari C. Pourquoi la curiethérapie reste-t-elle indispensable en 2017 ? Cancer Radiother 2018; 22:307-311. [DOI: 10.1016/j.canrad.2017.11.009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2017] [Accepted: 11/15/2017] [Indexed: 10/16/2022]
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35
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Beld E, Moerland MA, Zijlstra F, Viergever MA, Lagendijk JJW, Seevinck PR. MR-based source localization for MR-guided HDR brachytherapy. Phys Med Biol 2018. [PMID: 29516866 DOI: 10.1088/1361-6560/aab50b] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
For the purpose of MR-guided high-dose-rate (HDR) brachytherapy, a method for real-time localization of an HDR brachytherapy source was developed, which requires high spatial and temporal resolutions. MR-based localization of an HDR source serves two main aims. First, it enables real-time treatment verification by determination of the HDR source positions during treatment. Second, when using a dummy source, MR-based source localization provides an automatic detection of the source dwell positions after catheter insertion, allowing elimination of the catheter reconstruction procedure. Localization of the HDR source was conducted by simulation of the MR artifacts, followed by a phase correlation localization algorithm applied to the MR images and the simulated images, to determine the position of the HDR source in the MR images. To increase the temporal resolution of the MR acquisition, the spatial resolution was decreased, and a subpixel localization operation was introduced. Furthermore, parallel imaging (sensitivity encoding) was applied to further decrease the MR scan time. The localization method was validated by a comparison with CT, and the accuracy and precision were investigated. The results demonstrated that the described method could be used to determine the HDR source position with a high accuracy (0.4-0.6 mm) and a high precision (⩽0.1 mm), at high temporal resolutions (0.15-1.2 s per slice). This would enable real-time treatment verification as well as an automatic detection of the source dwell positions.
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Affiliation(s)
- E Beld
- Department of Radiotherapy, University Medical Center Utrecht, Heidelberglaan 100, 3584 CX, Utrecht, Netherlands
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Johansen JG, Rylander S, Buus S, Bentzen L, Hokland SB, Søndergaard CS, With AKM, Kertzscher G, Tanderup K. Time-resolved in vivo dosimetry for source tracking in brachytherapy. Brachytherapy 2018; 17:122-132. [DOI: 10.1016/j.brachy.2017.08.009] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2017] [Revised: 08/11/2017] [Accepted: 08/15/2017] [Indexed: 11/25/2022]
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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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Smith RL, Hanlon M, Panettieri V, Millar JL, Matheson B, Haworth A, Franich RD. An integrated system for clinical treatment verification of HDR prostate brachytherapy combining source tracking with pretreatment imaging. Brachytherapy 2018; 17:111-121. [DOI: 10.1016/j.brachy.2017.08.004] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2017] [Revised: 07/29/2017] [Accepted: 08/09/2017] [Indexed: 10/18/2022]
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In vivo dose verification method in catheter based high dose rate brachytherapy. Phys Med 2017; 44:1-10. [DOI: 10.1016/j.ejmp.2017.11.003] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/16/2017] [Revised: 11/03/2017] [Accepted: 11/04/2017] [Indexed: 11/19/2022] Open
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40
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Assessment of the implant geometry in fractionated interstitial HDR breast brachytherapy using an electromagnetic tracking system. Brachytherapy 2017; 17:94-102. [PMID: 29146103 DOI: 10.1016/j.brachy.2017.10.007] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2017] [Revised: 09/17/2017] [Accepted: 10/13/2017] [Indexed: 11/20/2022]
Abstract
PURPOSE During the partial-breast treatment course by interstitial brachytherapy, electromagnetic tracking (EMT) was applied to measure the implant geometry. Implant-geometry variation, choice of reference data, and three registration methods were assessed. METHODS AND MATERIALS The implant geometry was measured in 28 patients after catheter implantation (EMTbed), during CT imaging (EMTCT), and in each of up to n = 9 treatment fractions (EMTF(k), k = 1, 2,… n). EMTF(k) were registered to the planned implant reconstruction (CTplan) by using all dwell positions (DPs), the button centers, or three fiducial sensors on the patient's skin. Variation in implant geometry obtained from EMTF(k) was assessed for EMTbed, EMTCT, and CTplan. RESULTS EMT was used to measure 3932 catheters. A duration of 6.5 ± 1.7 min was needed for each implant measurement (mean, 17 catheters) plus setup of the EMT system. Data registration based on the DP deviated significantly lower than registration on button centers or fiducial sensors. Within a registration group, there was a <0.5-mm difference in the choice of reference data. Using CTplan as reference for registration, the mean residual distance of DPs on EMT-derived DPs was found at 2.1 ± 1.6 mm (EMTbed), 1.3 ± 0.9 mm (EMTCT), and 2.5 ± 1.5 mm (EMTF(k)). CONCLUSIONS EMT can assess the implant geometry in high-dose-rate interstitial brachytherapy breast treatments. EMTbed, EMTCT, and CTplan data can serve as reference for assessment of implant changes.
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Romanyukha AA, Carrara M, Tenconi C, Mazzeo D, Rossi G, Borroni M, Pignoli E, Cerrotta A, Cutajar D, Petasecca M, Lerch M, Bucci J, Rosenfeld AB. Applications of MOSkin dosimeters for quality assurance in gynecological HDR brachytherapy: An in-phantom feasibility study. RADIAT MEAS 2017. [DOI: 10.1016/j.radmeas.2016.12.010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Persson M, Nilsson J, Carlsson Tedgren Å. Experience of using MOSFET detectors for dose verification measurements in an end-to-end 192Ir brachytherapy quality assurance system. Brachytherapy 2017; 17:227-233. [PMID: 29110967 DOI: 10.1016/j.brachy.2017.09.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2016] [Revised: 09/22/2017] [Accepted: 09/22/2017] [Indexed: 11/26/2022]
Abstract
PURPOSE Establishment of an end-to-end system for the brachytherapy (BT) dosimetric chain could be valuable in clinical quality assurance. Here, the development of such a system using MOSFET (metal oxide semiconductor field effect transistor) detectors and experience gained during 2 years of use are reported with focus on the performance of the MOSFET detectors. METHODS AND MATERIALS A bolus phantom was constructed with two implants, mimicking prostate and head & neck treatments, using steel needles and plastic catheters to guide the 192Ir source and house the MOSFET detectors. The phantom was taken through the BT treatment chain from image acquisition to dose evaluation. During the 2-year evaluation-period, delivered doses were verified a total of 56 times using MOSFET detectors which had been calibrated in an external 60Co beam. An initial experimental investigation on beam quality differences between 192Ir and 60Co is reported. RESULTS The standard deviation in repeated MOSFET measurements was below 3% in the six measurement points with dose levels above 2 Gy. MOSFET measurements overestimated treatment planning system doses by 2-7%. Distance-dependent experimental beam quality correction factors derived in a phantom of similar size as that used for end-to-end tests applied on a time-resolved measurement improved the agreement. CONCLUSIONS MOSFET detectors provide values stable over time and function well for use as detectors for end-to-end quality assurance purposes in 192Ir BT. Beam quality correction factors should address not only distance from source but also phantom dimensions.
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Affiliation(s)
- Maria Persson
- Department of Medical Radiation Physics and Nuclear Medicine, Section for Radiotherapy Physics and Engineering, Karolinska University Hospital, Stockholm, Sweden.
| | - Josef Nilsson
- Department of Medical Radiation Physics and Nuclear Medicine, Section for Radiotherapy Physics and Engineering, Karolinska University Hospital, Stockholm, Sweden
| | - Åsa Carlsson Tedgren
- Department of Medical Radiation Physics and Nuclear Medicine, Section for Radiotherapy Physics and Engineering, Karolinska University Hospital, Stockholm, Sweden; Department of Medical and Health Sciences and Center for Medical Image Science and Visualization, Radiation Physics, Linköping University, Linköping, Sweden
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Semiconductor real-time quality assurance dosimetry in brachytherapy. Brachytherapy 2017; 17:133-145. [PMID: 28964727 DOI: 10.1016/j.brachy.2017.08.013] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2017] [Revised: 08/22/2017] [Accepted: 08/28/2017] [Indexed: 11/23/2022]
Abstract
With the increase in complexity of brachytherapy treatments, there has been a demand for the development of sophisticated devices for delivery verification. The Centre for Medical Radiation Physics (CMRP), University of Wollongong, has demonstrated the applicability of semiconductor devices to provide cost-effective real-time quality assurance for a wide range of brachytherapy treatment modalities. Semiconductor devices have shown great promise to the future of pretreatment and in vivo quality assurance in a wide range of brachytherapy treatments, from high-dose-rate (HDR) prostate procedures to eye plaque treatments. The aim of this article is to give an insight into several semiconductor-based dosimetry instruments developed by the CMRP. Applications of these instruments are provided for breast and rectal wall in vivo dosimetry in HDR brachytherapy, urethral in vivo dosimetry in prostate low-dose-rate (LDR) brachytherapy, quality assurance of HDR brachytherapy afterloaders, HDR pretreatment plan verification, and real-time verification of LDR and HDR source dwell positions.
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Carrara M, Romanyukha A, Tenconi C, Mazzeo D, Cerrotta A, Borroni M, Cutajar D, Petasecca M, Lerch M, Bucci J, Richetti A, Presilla S, Fallai C, Gambarini G, Pignoli E, Rosenfeld A. Clinical application of MOSkin dosimeters to rectal wall in vivo dosimetry in gynecological HDR brachytherapy. Phys Med 2017; 41:5-12. [DOI: 10.1016/j.ejmp.2017.05.003] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/11/2017] [Revised: 04/27/2017] [Accepted: 05/01/2017] [Indexed: 10/19/2022] Open
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Hayes RB, Sholom S. Retrospective Imaging and Characterization of Nuclear Material. HEALTH PHYSICS 2017; 113:91-101. [PMID: 28658054 DOI: 10.1097/hp.0000000000000680] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Modern techniques for detection of covert nuclear material requires some combination of real time measurement and/or sampling of the material. More common is real time measurement of the ionizing emission caused by radioactive decay or through the materials measured in response to external interrogation radiation. One can expose the suspect material with various radiation types, including high energy photons such as x rays or with larger particles such as neutrons and muons, to obtain images or measure nuclear reactions induced in the material. Stand-off detection using imaging modalities similar to those in the medical field can be accomplished, or simple collimated detectors can be used to localize radioactive materials. In all such cases, the common feature is that some or all of the nuclear materials have to be present for the measurement, which makes sense; as one might ask, "How you can measure something that is not there?" The current work and results show how to do exactly that: characterize nuclear materials after they have been removed from an area leaving no chemical trace. This new approach is demonstrated to be fully capable of providing both previous source spatial distribution and emission energy grouping. The technique uses magnetic resonance for organic insulators and/or luminescence techniques on ubiquitous refractory materials similar in theory to the way the nuclear industry carries out worker personnel dosimetry. Spatial information is obtained by acquiring gridded samples for dosimetric measurements, while energy information comes through dose depth profile results that are functions of the incident radiation energies.
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Affiliation(s)
- Robert B Hayes
- *North Carolina State University, Nuclear Engineering Department, 2500 Stinson Dr., Raleigh, NC 27695-7909; †Oklahoma State University, Physics Department, 1110 S. Innovation Way Dr., Stillwater, OK 74074
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Kertzscher G, Beddar S. Inorganic scintillator detectors for real-time verification during brachytherapy. ACTA ACUST UNITED AC 2017. [DOI: 10.1088/1742-6596/847/1/012036] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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In vivo dosimetry in gynecological applications-A feasibility study. Brachytherapy 2017; 17:146-153. [PMID: 28528720 DOI: 10.1016/j.brachy.2017.04.240] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2016] [Revised: 03/24/2017] [Accepted: 04/15/2017] [Indexed: 11/22/2022]
Abstract
PURPOSE To investigate the feasibility of in vivo dosimetry using microMOSFET dosimeters in patients treated with brachytherapy using two types of gynecological applicators. METHODS AND MATERIALS In this study, a microMOSFET was placed in an empty needle of an Utrecht Interstitial Fletcher applicator or MUPIT (Martinez Universal Perineal Interstitial Template) applicator for independent verification of treatment delivery. Measurements were performed in 10 patients, with one to three microMOSFETs per applicator and repeated for one to four fractions, resulting in 50 in vivo measurements. Phantom measurements were used to determine characteristics of the microMOSFETs. RESULTS Phantom measurements showed a linear relationship between dose and microMOSFET threshold voltage, and a calibration coefficient (mV/cGy) was determined. Reproducibility of repeated 50 cGy irradiations was 2% (1 standard deviation). Distance and angle dependencies were measured and correction factors were determined. Subsequently, three microMOSFETs were placed in a phantom to measure a validation plan. The difference between predicted and measured dose was less than the measurement uncertainty (±9%, 2 standard deviations). In vivo measurements were corrected for distance and angle dependencies. Differences between predicted and measured dose in the patients were smaller than the measurement uncertainty for the majority of the measurements. CONCLUSIONS In vivo dosimetry using microMOSFETs in MUPIT and Utrecht Interstitial Fletcher applicators has proved to be feasible. Reimaging should be performed after detection of differences larger than 10% between predicted and measured dose to verify the applicator configuration. Movement of the applicator relative to the target or organs at risk is undetectable with this method.
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Kertzscher G, Beddar S. Inorganic scintillation detectors based on Eu-activated phosphors for 192Ir brachytherapy. Phys Med Biol 2017; 62:5046-5075. [PMID: 28475494 DOI: 10.1088/1361-6560/aa716e] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The availability of real-time treatment verification during high-dose-rate (HDR) brachytherapy is currently limited. Therefore, we studied the luminescence properties of the widely commercially available scintillators using the inorganic materials Eu-activated phosphors Y2O3:Eu, YVO4:Eu, Y2O2S:Eu, and Gd2O2S:Eu to determine whether they could be used to accurately and precisely verify HDR brachytherapy doses in real time. The suitability for HDR brachytherapy of inorganic scintillation detectors (ISDs) based on the 4 Eu-activated phosphors in powder form was determined based on experiments with a 192Ir HDR brachytherapy source. The scintillation intensities of the phosphors were 16-134 times greater than that of the commonly used organic plastic scintillator BCF-12. High signal intensities were achieved with an optimized packing density of the phosphor mixture and with a shortened fiber-optic cable. The influence of contaminating Cerenkov and fluorescence light induced in the fiber-optic cable (stem signal) was adequately suppressed by inserting between the fiber-optic cable and the photodetector a 25 nm band-pass filter centered at the emission peak. The spurious photoluminescence signal induced by the stem signal was suppressed by placing a long-pass filter between the scintillation detector volume and the fiber-optic cable. The time-dependent luminescence properties of the phosphors were quantified by measuring the non-constant scintillation during irradiation and the afterglow after the brachytherapy source had retracted. We demonstrated that a mixture of Y2O3:Eu and YVO4:Eu suppressed the time-dependence of the ISDs and that the time-dependence of Y2O2S:Eu and Gd2O2S:Eu introduced large measurement inaccuracies. We conclude that ISDs based on a mixture of Y2O3:Eu and YVO4:Eu are promising candidates for accurate and precise real-time verification technology for HDR BT that is cost effective and straightforward to manufacture. Widespread dissemination of this technology could lead to an improved understanding of error types and frequencies during BT and to improved patient safety during treatment.
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Affiliation(s)
- Gustavo Kertzscher
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, TX, United States of America
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Real-Time Verification of a High-Dose-Rate Iridium 192 Source Position Using a Modified C-Arm Fluoroscope. Int J Radiat Oncol Biol Phys 2016; 97:858-865. [PMID: 28244423 DOI: 10.1016/j.ijrobp.2016.12.005] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2016] [Revised: 10/25/2016] [Accepted: 12/02/2016] [Indexed: 11/21/2022]
Abstract
PURPOSE High-dose-rate (HDR) brachytherapy misdeliveries can occur at any institution, and they can cause disastrous results. Even a patient's death has been reported. Misdeliveries could be avoided with real-time verification methods. In 1996, we developed a modified C-arm fluoroscopic verification of an HDR Iridium 192 source position prevent these misdeliveries. This method provided excellent image quality sufficient to detect errors, and it has been in clinical use at our institutions for 20 years. The purpose of the current study is to introduce the mechanisms and validity of our straightforward C-arm fluoroscopic verification method. METHODS AND MATERIALS Conventional X-ray fluoroscopic images are degraded by spurious signals and quantum noise from Iridium 192 photons, which make source verification impractical. To improve image quality, we quadrupled the C-arm fluoroscopic X-ray dose per pulse. The pulse rate was reduced by a factor of 4 to keep the average exposure compliant with Japanese medical regulations. The images were then displayed with quarter-frame rates. RESULTS Sufficient quality was obtained to enable observation of the source position relative to both the applicators and the anatomy. With this method, 2 errors were detected among 2031 treatment sessions for 370 patients within a 6-year period. CONCLUSIONS With the use of a modified C-arm fluoroscopic verification method, treatment errors that were otherwise overlooked were detected in real time. This method should be given consideration for widespread use.
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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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