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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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Georgi PD, Jørgensen EB, Heidotting M, Tanderup K, Kertzscher G, Johansen JG. A simple calibration routine for small inorganic scintillation detectors for in vivo dosimetry during brachytherapy. Brachytherapy 2024:S1538-4721(24)00070-9. [PMID: 38853063 DOI: 10.1016/j.brachy.2024.05.001] [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: 09/22/2023] [Revised: 04/04/2024] [Accepted: 05/07/2024] [Indexed: 06/11/2024]
Abstract
BACKGROUND In vivo dosimetry (IVD) is rarely performed in brachytherapy (BT), allowing potential dose misadministration to go unnoticed. This study presents a clinical routine-calibration method of detectors for IVD in high (HDR) and pulsed dose rate (PDR) Ir-192 BT. PURPOSE To evaluate the dosimetric precision and feasibility of an in-clinic calibration routine of detectors for IVD in afterloading BT. METHODS Calibrations were performed in a PMMA phantom with two needles inserted 20 mm apart. The source was loaded in one of the needles at 15 dwells for 10 s. The detector was placed in the other needle, and its signal was recorded. The mean signal at each dwell position was fitted to the expected dose rate with the calibration factor and the detector's longitudinal position being free parameters. The method was tested with an inorganic scintillation detector using one Ir-192 FlexiSource HDR and two Ir-192 GammaMedPlus PDR sources and followed by validation measurements in water. RESULTS The standard measurement uncertainty (k = 1) of the calibration factor in absolute terms (Gy/s) was 3.2/3.4% for the HDR/PDR source. The uncertainty was dominated by source strength uncertainty, and the precision of the method was <1%. The mean ± 1SD of the difference in measured and expected dose rate during validation was 1.5 ± 4.7% (HDR) and 0.0 ± 4.1% (PDR) with a positional uncertainty in the setup of 0.33/0.23 mm (HDR/PDR) (k = 1). CONCLUSION A precise and feasible in-clinic calibration method for IVD and source strength consistency tests in BT was presented.
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Affiliation(s)
- Peter D Georgi
- Department of Clinical Medicine, Aarhus University, Aarhus, Denmark.
| | - Erik B Jørgensen
- Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | | | - Kari Tanderup
- Department of Clinical Medicine, Aarhus University, Aarhus, Denmark; Department of Oncology, Aarhus University Hospital, Aarhus, Denmark
| | | | - Jacob G Johansen
- Department of Clinical Medicine, Aarhus University, Aarhus, Denmark; Department of Oncology, Aarhus University Hospital, Aarhus, Denmark
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Tho D, Bélanger C, Jørgensen EB, Tanguay J, Rosales HML, Beddar S, Johansen JG, Kertzscher G, Lavallée MC, Beaulieu L. Establishing a fingerprinting method for fast catheter identification in HDR brachytherapy in vivo dosimetry. Brachytherapy 2024; 23:165-172. [PMID: 38281894 DOI: 10.1016/j.brachy.2023.10.004] [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: 07/06/2022] [Revised: 08/23/2023] [Accepted: 10/06/2023] [Indexed: 01/30/2024]
Abstract
PURPOSE To use quantities measurable during in vivo dosimetry to build unique channel identifiers, that enable detection of brachytherapy errors. MATERIALS AND METHODS Treatment plan of 360 patients with prostate cancer who underwent high-dose-rate brachytherapy (range, 16-25 catheters; mean, 17) were used. A single point virtual dosimeter was placed at multiple positions within the treatment geometry, and the source-dosimeter distance and dwell time were determined for each dwell position in each catheter. These values were compared across all catheters, dwell position by dwell position, simulating a treatment delivery. A catheter was considered uniquely identified if, for a given dwell position, no other catheters had the same measured values. The minimum number of dwell positions needed to identify a specific catheter and the optimal dosimeter location uniquely were determined. The radial (r) and vertical (z) dimensions of the source-dosimeter distance were also examined for their utility in discriminating catheters. RESULTS Using a virtual dosimeter with no uncertainties, all catheters were identified in 359 of the 360 cases with 9 dwell position measurements. When only the dwell time were measured, all catheters were uniquely identified after 1 dwell position. With a 2-mm spatial accuracy (r,z), all catheters were identified in 94% of the plans. Simultaneous measurement of source-dosimeter distance and dwell time ensured full catheter identification in all plans ranging from 2 to 6 dwell positions. The number of dwell positions needed to uniquely identify all catheters was lower when the distance from the implant center was higher. CONCLUSIONS The most efficient fingerprinting approach involved combining source-dosimeter distance (i.e., source tracking) and dwell time. The further the dosimeter is placed from the center of the implant the better it can uniquely identify catheters.
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Affiliation(s)
- Daline Tho
- Centre Intégré De Cancérologie, CHU De Québec, Université Laval, Centre De Recherche Chu De Québec, Québec, Canada; Département De Physique, De Génie Physique Et D'optique, Centre De Recherche Sur Le Cancer, Québec, Canada.
| | - Cédric Bélanger
- Centre Intégré De Cancérologie, CHU De Québec, Université Laval, Centre De Recherche Chu De Québec, Québec, Canada; Département De Physique, De Génie Physique Et D'optique, Centre De Recherche Sur Le Cancer, Québec, Canada
| | - Erik B Jørgensen
- Department of Oncology, Aarhus University Hospital, Aarhus, Denmark
| | - Jérémie Tanguay
- Centre Intégré De Cancérologie, CHU De Québec, Université Laval, Centre De Recherche Chu De Québec, Québec, Canada; Département De Physique, De Génie Physique Et D'optique, Centre De Recherche Sur Le Cancer, Québec, Canada
| | - Haydee M L Rosales
- Centre Intégré De Cancérologie, CHU De Québec, Université Laval, Centre De Recherche Chu De Québec, Québec, Canada; Département De Physique, De Génie Physique Et D'optique, Centre De Recherche Sur Le Cancer, Québec, Canada
| | - Sam Beddar
- Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX
| | - Jacob G Johansen
- Department of Oncology, Aarhus University Hospital, Aarhus, Denmark
| | | | - Marie-Claude Lavallée
- Centre Intégré De Cancérologie, CHU De Québec, Université Laval, Centre De Recherche Chu De Québec, Québec, Canada; Département De Physique, De Génie Physique Et D'optique, Centre De Recherche Sur Le Cancer, Québec, Canada
| | - Luc Beaulieu
- Centre Intégré De Cancérologie, CHU De Québec, Université Laval, Centre De Recherche Chu De Québec, Québec, Canada; Département De Physique, De Génie Physique Et D'optique, Centre De Recherche Sur Le Cancer, Québec, Canada
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Koprivec D, Belanger C, Beaulieu L, Chatigny PY, Rosenfeld A, Cutajar D, Petasecca M, Howie A, Bucci J, Poder J. Development of patient and catheter specific error thresholds for high dose rate prostate brachytherapy. Med Phys 2024; 51:2144-2154. [PMID: 38308854 DOI: 10.1002/mp.16971] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Revised: 12/21/2023] [Accepted: 01/14/2024] [Indexed: 02/05/2024] Open
Abstract
BACKGROUND In-vivo source tracking has been an active topic of research in the field of high-dose rate brachytherapy in recent years to verify accuracy in treatment delivery. Although detection systems for source tracking are being developed, the allowable threshold of treatment error is still unknown and is likely patient-specific due to anatomy and planning variation. PURPOSE The purpose of this study was to determine patient and catheter-specific shift error thresholds for in-vivo source tracking during high-dose-rate prostate brachytherapy (HDRPBT). METHODS A module was developed in the previously described graphical processor unit multi-criteria optimization (gMCO) algorithm. The module generates systematic catheter shift errors retrospectively into HDRPBT treatment plans, performed on 50 patients. The catheter shift model iterates through the number of catheters shifted in the plan (from 1 to all catheters), the direction of shift (superior, inferior, medial, lateral, cranial, and caudal), and the magnitude of catheter shift (1-6 mm). For each combination of these parameters, 200 error plans were generated, randomly selecting the catheters in the plan to shift. After shifts were applied, dose volume histogram (DVH) parameters were re-calculated. Catheter shift thresholds were then derived based on plans where DVH parameters were clinically unacceptable (prostate V100 < 95%, urethra D0.1cc > 118%, and rectum Dmax > 80%). Catheter thresholds were also Pearson correlated to catheter robustness values. RESULTS Patient-specific thresholds varied between 1 to 6 mm for all organs, in all shift directions. Overall, patient-specific thresholds typically decrease with an increasing number of catheters shifted. Anterior and inferior directions were less sensitive than other directions. Pearson's correlation test showed a strong correlation between catheter robustness and catheter thresholds for the rectum and urethra, with correlation values of -0.81 and -0.74, respectively (p < 0.01), but no correlation was found for the prostate. CONCLUSIONS It was possible to determine thresholds for each patient, with thresholds showing dependence on shift direction, and number of catheters shifted. Not every catheter combination is explorable, however, this study shows the feasibility to determine patient-specific thresholds for clinical application. The correlation of patient-specific thresholds with the equivalent robustness value indicated the need for robustness consideration during plan optimization and treatment planning.
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Affiliation(s)
- Dylan Koprivec
- Centre for Medical Radiation Physics, University of Wollongong, Wollongong, Australia
| | - Cedric Belanger
- Département de physique, de génie physique et d'optique et Centre de recherche sur le cancer de l'Université Laval, CHU de Québec, Québec, Canada
- Département de radio-oncologie et Centre de recherche du CHU de Québec, CHU de Québec - Université Laval, Québec, Canada
| | - Luc Beaulieu
- Département de physique, de génie physique et d'optique et Centre de recherche sur le cancer de l'Université Laval, CHU de Québec, Québec, Canada
- Département de radio-oncologie et Centre de recherche du CHU de Québec, CHU de Québec - Université Laval, Québec, Canada
| | - Philippe Y Chatigny
- Département de physique, de génie physique et d'optique et Centre de recherche sur le cancer de l'Université Laval, CHU de Québec, Québec, Canada
- Département de radio-oncologie et Centre de recherche du CHU de Québec, CHU de Québec - Université Laval, Québec, Canada
| | - Anatoly Rosenfeld
- Centre for Medical Radiation Physics, University of Wollongong, Wollongong, Australia
| | - Dean Cutajar
- Centre for Medical Radiation Physics, University of Wollongong, Wollongong, Australia
- St George Cancer Care Centre, Kogarah, New South Wales, Australia
| | - Marco Petasecca
- Centre for Medical Radiation Physics, University of Wollongong, Wollongong, Australia
| | - Andrew Howie
- St George Cancer Care Centre, Kogarah, New South Wales, Australia
| | - Joseph Bucci
- St George Cancer Care Centre, Kogarah, New South Wales, Australia
| | - Joel Poder
- Centre for Medical Radiation Physics, University of Wollongong, Wollongong, Australia
- St George Cancer Care Centre, Kogarah, New South Wales, Australia
- School of Physics, University of Sydney, Camperdown, New South Wales, Australia
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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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Tho D, Lavallée M, Beaulieu L. A scintillation dosimeter with real-time positional tracking information for in vivo dosimetry error detection in HDR brachytherapy. J Appl Clin Med Phys 2023; 24:e14150. [PMID: 37731203 PMCID: PMC10691625 DOI: 10.1002/acm2.14150] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2023] [Revised: 07/26/2023] [Accepted: 08/09/2023] [Indexed: 09/22/2023] Open
Abstract
PURPOSE To evaluate the performance of an electromagnetic (EM)-tracked scintillation dosimeter in detecting source positional errors of IVD in HDR brachytherapy treatment. MATERIALS AND METHODS Two different scintillator dosimeter prototypes were coupled to 5 degrees-of-freedom (DOF) EM sensors read by an Aurora V3 system. The scintillators used were a 0.3 × 0.4 × 0.4 mm3 ZnSe:O and a BCF-60 plastic scintillator of 0.5 mm diameter and 2.0 mm in length (Saint-Gobain Crystals). The sensors were placed at the dosimeter's tip at 20.0 mm from the scintillator. The EM sampling rate was 40/s while the scintillator signal was sampled at 100 000/s using two photomultiplier tubes from Hamamatsu (series H10722) connected to a data acquisition board. A high-pass filter and a low-pass filter were used to separate the light signal into two different channels. All measurements were performed with an afterloader unit (Flexitron-Elekta AB, Sweden) in full-scattered (TG43) conditions. EM tracking was further used to provide distance/angle-dependent energy correction for the ZnSe:O inorganic scintillator. For the error detection part, lateral shifts of 0.5 to 3 mm were induced by moving the source away from its planned position. Indexer length (longitudinal) errors between 0.5 to 10 mm were also introduced. The measured dose rate difference was converted to a shift distance, with and without using the positional information from the EM sensor. RESULTS The inorganic scintillator had both a signal-to-noise-ratio (SNR) and signal-to-background-ratio (SBR) close to 70 times higher than those of the plastic scintillator. The mean absolute difference from the dose measurement to the dose calculated with TG-43U1 was 1.5% ±0.7%. The mean absolute error for BCF-60 detector was 1.7%± 1.2 % $\pm 1.2\%$ when compared to TG-43 calculations formalism. With the inorganic scintillator and EM tracking, a maximum area under the curve (AUC) gain of 24.0% was obtained for a 0.5-mm lateral shift when using the EMT data with the ZnSe:O. Lower AUC gains were obtained for a 3-mm lateral shifts with both scintillators. For the plastic scintillator, the highest gain from using EM tracking information occurred for a 0.5-mm lateral shift at 20 mm from the source. The maximal gain (17.4%) for longitudinal errors was found at the smallest shifts (0.5 mm). CONCLUSIONS This work demonstrates that integrating EM tracking to in vivo scintillation dosimeters enables the detection of smaller shifts, by decreasing the dosimeter positioning uncertainty. It also serves to perform position-dependent energy correction for the inorganic scintillator,providing better SNR and SBR, allowing detection of errors at greater distances from the source.
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Affiliation(s)
- Daline Tho
- Department of Radiation OncologyThe University of Texas MD Anderson Cancer CenterHoustonTexasUSA
| | - Marie‐Claude Lavallée
- Département de physique, de génie physique et d'optique, et Centre de recherche sur le cancerUniversité LavalQuébecQuébecCanada
- Service de physique médicale et de radioprotection, Centre intégré de cancérologieCHU de Québec‐Université Laval et Centre de recherche du CHU de QuébecQuébecCanada
| | - Luc Beaulieu
- Département de physique, de génie physique et d'optique, et Centre de recherche sur le cancerUniversité LavalQuébecQuébecCanada
- Service de physique médicale et de radioprotection, Centre intégré de cancérologieCHU de Québec‐Université Laval et Centre de recherche du CHU de QuébecQuébecCanada
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Oliver S, Giménez-Alventosa V, Berumen F, Gimenez V, Beaulieu L, Ballester F, Vijande J. Benchmark of the PenRed Monte Carlo framework for HDR brachytherapy. Z Med Phys 2023; 33:511-528. [PMID: 36509574 PMCID: PMC10751717 DOI: 10.1016/j.zemedi.2022.11.002] [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: 07/04/2022] [Revised: 09/28/2022] [Accepted: 11/02/2022] [Indexed: 12/13/2022]
Abstract
PURPOSE The purpose of this study is to validate the PenRed Monte Carlo framework for clinical applications in brachytherapy. PenRed is a C++ version of Penelope Monte Carlo code with additional tallies and utilities. METHODS AND MATERIALS Six benchmarking scenarios are explored to validate the use of PenRed and its improved bachytherapy-oriented capabilities for HDR brachytherapy. A new tally allowing the evaluation of collisional kerma for any material using the track length kerma estimator and the possibility to obtain the seed positions, weights and directions processing directly the DICOM file are now implemented in the PenRed distribution. The four non-clinical test cases developed by the Joint AAPM-ESTRO-ABG-ABS WG-DCAB were evaluated by comparing local and global absorbed dose differences with respect to established reference datasets. A prostate and a palliative lung cases, were also studied. For them, absorbed dose ratios, global absorbed dose differences, and cumulative dose-volume histograms were obtained and discussed. RESULTS The air-kerma strength and the dose rate constant corresponding to the two sources agree with the reference datatests within 0.3% (Sk) and 0.1% (Λ). With respect to the first three WG-DCAB test cases, more than 99.8% of the voxels present local (global) differences within ±1%(±0.1%) of the reference datasets. For test Case 4 reference dataset, more than 94.9%(97.5%) of voxels show an agreement within ±1%(±0.1%), better than similar benchmarking calculations in the literature. The track length kerma estimator scorer implemented increases the numerical efficiency of brachytherapy calculations two orders of magnitude, while the specific brachytherapy source allows the user to avoid the use of error-prone intermediate steps to translate the DICOM information into the simulation. In both clinical cases, only minor absorbed dose differences arise in the low-dose isodoses. 99.8% and 100% of the voxels have a global absorbed dose difference ratio within ±0.2% for the prostate and lung cases, respectively. The role played by the different segmentation and composition material in the bone structures was discussed, obtaining negligible absorbed dose differences. Dose-volume histograms were in agreement with the reference data. CONCLUSIONS PenRed incorporates new tallies and utilities and has been validated for its use for detailed and precise high-dose-rate brachytherapy simulations.
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Affiliation(s)
- Sandra Oliver
- Instituto de Seguridad Industrial, Radiofísica y Medioambiental (ISIRYM), Universitat Politècnica de València, Camí de Vera s/n, 46022 València, Spain.
| | - Vicent Giménez-Alventosa
- Escuela de Ciencias, Ingeniería y Diseño, Universidad Europea de Valencia, Paseo de la Alameda 7, 46010 València, Spain; Instituto de Instrumentación para Imagen Molecular (I3M), Centro mixto CSIC - Universitat Politècnica de València, Camí de Vera s/n, 46022 València, Spain
| | - Francisco Berumen
- Département de Radio-Oncologie et Axe oncologie du Centre de recherche du CHU de Québec, CHU de Québec, Québec, QC, Canada; Département de Physique, de Génie Physique et d'Optique et Centre de Recherche sur le Cancer, Université Laval, Québec, QC, Canada
| | - Vicente Gimenez
- Departament de Física Teórica and IFIC, Universitat de València-CSIC, Dr. Moliner, 50, 46100 Burjassot, València, Spain
| | - Luc Beaulieu
- Département de Radio-Oncologie et Axe oncologie du Centre de recherche du CHU de Québec, CHU de Québec, Québec, QC, Canada; Département de Physique, de Génie Physique et d'Optique et Centre de Recherche sur le Cancer, Université Laval, Québec, QC, Canada
| | - Facundo Ballester
- Departamento de Física Atómica, Molecular y Nuclear. IRIMED, IIS-La Fe-Universitat de Valencia, 46100 Burjassot, Spain
| | - Javier Vijande
- Departamento de Física Atómica, Molecular y Nuclear. IRIMED, IIS-La Fe-Universitat de Valencia, 46100 Burjassot, Spain; Instituto de Física Corpuscular, IFIC (UV-CSIC), 46100 Burjassot, Spain
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Gonod M, Suarez MA, Avila CC, Karakhanyan V, Eustache C, Laskri S, Crouzilles J, Vinchant JF, Aubignac L, Grosjean T. Six-probe scintillator dosimeter for treatment verification in HDR-brachytherapy. Med Phys 2023; 50:7192-7202. [PMID: 37738612 DOI: 10.1002/mp.16745] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2023] [Revised: 07/28/2023] [Accepted: 08/01/2023] [Indexed: 09/24/2023] Open
Abstract
BACKGROUND In vivo dosimetry (IVD) is gaining interest for treatment delivery verification in HDR-brachytherapy. Time resolved methods, including source tracking, have the ability both to detect treatment errors in real time and to minimize experimental uncertainties. Multiprobe IVD architectures holds promise for simultaneous dose determinations at the targeted tumor and surrounding healthy tissues while enhancing measurement accuracy. However, most of the multiprobe dosimeters developed so far either suffer from compactness issues or rely on complex data post-treatment. PURPOSE We introduce a novel concept of a compact multiprobe scintillator detector and demonstrate its applicability in HDR-brachytherapy. Our fabricated seven-fiber probing system is sufficiently narrow to be inserted in a brachytherapy needle or in a catheter. METHODS Our multiprobe detection system results from the parallel implementation of six miniaturized inorganic Gd2 O2 S:Tb scintillator detectors at the end of a bundle of seven fibers, one fiber is kept bare to assess the stem effect. The resulting system, which is narrower than 320 microns, is tested with a MicroSelectron 9.14 Ci Ir-192 HDR afterloader, in a water phantom. The detection signals from all six probes are simultaneously read with a sCMOS camera (at a rate of 0.06 s). The camera is coupled to a chromatic filter to cancel Cerenkov signal induced within the fibers upon exposure. By implementing an aperiodic array of six scintillating cells along the bundle axis, we first determine the range of inter-probe spacings leading to optimal source tracking accuracy (first tracking method). Then, three different source tracking algorithms involving all the scintillating probes are tested and compared. In each of these four methods, dwell positions are assessed from dose measurements and compared to the treatment plan. Dwell time is also determined and compared to the treatment plan. RESULTS The optimum inter-probe spacing for an accurate source tracking ranges from 15 to 35 mm. The optimum detection algorithm consists of adding the readout signals from all detector probes. In that case, the error to the planned dwell positions is of 0.01 ± 0.14 mm and 0.02 ± 0.29 mm at spacings between the source and detector axes of 5.5 and 40 mm, respectively. Using this approach, the average deviations to the expected dwell time are of- 0.006 ± 0.009 $-0.006\,\pm \,0.009$ s and- 0.008 ± 0.058 $-0.008\, \pm 0.058$ s, at spacings between source and probe axes of 5.5 and 20 mm, respectively. CONCLUSIONS Our six-probe Gd2 O2 S:Tb dosimeter coupled to a sCMOS camera can perform time-resolved treatment verification in HDR brachytherapy. This detection system of high spatial and temporal resolutions (0.25 mm and 0.06 s, respectively) provides a precise information on the treatment delivery via a dwell time and position verification of unmatched accuracy.
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Affiliation(s)
- Mathieu Gonod
- Medical Physics Department, Centre Georges François Leclerc (CGFL), Dijon, France
| | | | | | - Vage Karakhanyan
- FEMTO-ST Institute, CNRS, University of Franche-Comté, Besançon, France
| | - Clément Eustache
- FEMTO-ST Institute, CNRS, University of Franche-Comté, Besançon, France
| | - Samir Laskri
- SEDI-ATI Fibres Optiques, Évry-Courcouronnes, France
| | | | | | - Léone Aubignac
- Medical Physics Department, Centre Georges François Leclerc (CGFL), Dijon, France
| | - Thierry Grosjean
- FEMTO-ST Institute, CNRS, University of Franche-Comté, Besançon, France
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9
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Dürrbeck C, Schuster S, Sauer BC, Abu-Hossin N, Strnad V, Fietkau R, Bert C. Localization of reference points in electromagnetic tracking data and their application for treatment error detection in interstitial breast brachytherapy. Med Phys 2023; 50:5772-5783. [PMID: 37458615 DOI: 10.1002/mp.16629] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Revised: 06/27/2023] [Accepted: 06/29/2023] [Indexed: 09/11/2023] Open
Abstract
BACKGROUND Electromagnetic tracking (EMT) is a promising technology that holds great potential to advance patient-specific pre-treatment verification in interstitial brachytherapy (iBT). It allows easy determination of the implant geometry without line-of-sight restrictions and without dose exposure to the patient. What it cannot provide, however, is a link to anatomical landmarks, such as the exit points of catheters or needles on the skin surface. These landmarks are required for the registration of EMT data with other imaging modalities and for the detection of treatment errors such as incorrect indexer lengths, and catheter or needle shifts. PURPOSE To develop an easily applicable method to detect reference points in the positional data of the trajectory of an EMT sensor, specifically the exit points of catheters in breast iBT, and to apply the approach to pre-treatment error detection. METHODS Small metal objects were attached to catheter fixation buttons that rest against the breast surface to intentionally induce a local, spatially limited perturbation of the magnetic field on which the working principle of EMT relies. This perturbation can be sensed by the EMT sensor as it passes by, allowing it to localize the metal object and thus the catheter exit point. For the proof-of-concept, different small metal objects (magnets, washers, and bushes) and EMT sensor drive speeds were used to find the optimal parameters. The approach was then applied to treatment error detection and validated in-vitro on a phantom. Lastly, the in-vivo feasibility of the approach was tested on a patient cohort of four patients to assess the impact on the clinical workflow. RESULTS All investigated metal objects were able to measurably perturb the magnetic field, which resulted in missing sensor readings, that is two data gaps, one for the sensor moving towards the tip end and one when retracting from there. The size of the resulting data gaps varied depending on the choice of gap points used for calculation of the gap size; it was found that the start points of the gaps in both directions showed the smallest variability. The median size of data gaps was ⩽8 mm for all tested materials and sensor drive speeds. The variability of the determined object position was ⩽0.5 mm at a speed of 1.0 cm/s and ⩽0.7 mm at 2.5 cm/s, with an increase up to 2.3 mm at 5.0 cm/s. The in-vitro validation of the error detection yielded a 100% detection rate for catheter shifts of ≥2.2 mm. All simulated wrong indexer lengths were correctly identified. The in-vivo feasibility assessment showed that the metal objects did not interfere with the routine clinical workflow. CONCLUSIONS The developed approach was able to successfully detect reference points in EMT data, which can be used for registration to other imaging modalities, but also for treatment error detection. It can thus advance the automation of patient-specific, pre-treatment quality assurance in iBT.
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Affiliation(s)
- Christopher Dürrbeck
- Department of Radiation Oncology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany
- Comprehensive Cancer Center Erlangen-EMN (CCC ER-EMN), Erlangen, Germany
| | - Sabrina Schuster
- Department of Radiation Oncology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany
- Comprehensive Cancer Center Erlangen-EMN (CCC ER-EMN), Erlangen, Germany
| | - Birte Christina Sauer
- Department of Radiation Oncology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany
- Comprehensive Cancer Center Erlangen-EMN (CCC ER-EMN), Erlangen, Germany
| | - Nadin Abu-Hossin
- Department of Radiation Oncology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany
- Comprehensive Cancer Center Erlangen-EMN (CCC ER-EMN), Erlangen, Germany
| | - Vratislav Strnad
- Department of Radiation Oncology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany
- Comprehensive Cancer Center Erlangen-EMN (CCC ER-EMN), Erlangen, Germany
| | - Rainer Fietkau
- Department of Radiation Oncology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany
- Comprehensive Cancer Center Erlangen-EMN (CCC ER-EMN), Erlangen, Germany
| | - Christoph Bert
- Department of Radiation Oncology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany
- Comprehensive Cancer Center Erlangen-EMN (CCC ER-EMN), Erlangen, Germany
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10
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Sung S, Lee M, Choi HJ, Park H, Cheon BW, Min CH, Yeom YS, Kim H, You SH, Choi HJ. Feasibility of internal-source tracking with C-arm CT/SPECT imaging with limited-angle projection data for online in vivo dose verification in brachytherapy: A Monte Carlo simulation study. Brachytherapy 2023; 22:673-685. [PMID: 37301703 DOI: 10.1016/j.brachy.2023.05.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2022] [Revised: 03/13/2023] [Accepted: 05/07/2023] [Indexed: 06/12/2023]
Abstract
PURPOSE The current protocol for use of the image-guided adaptive brachytherapy (IGABT) procedure entails transport of a patient between the treatment room and the 3-D tomographic imaging room after implantation of the applicators in the body, which movement can cause position displacement of the applicator. Moreover, it is not possible to track 3-D radioactive source movement inside the body, even though there can be significant inter- and intra-fractional patient-setup changes. In this paper, therefore, we propose an online single-photon emission computed tomography (SPECT) imaging technique with a combined C-arm fluoroscopy X-ray system and attachable parallel-hole collimator for internal radioactive source tracking of every source position in the applicator. METHODS AND MATERIALS In the present study, using Geant4 Monte Carlo (MC) simulation, the feasibility of high-energy gamma detection with a flat-panel detector for X-ray imaging was assessed. Further, a parallel-hole collimator geometry was designed based on an evaluation of projection image quality for a 192Ir point source, and 3-D limited-angle SPECT-image-based source-tracking performances were evaluated for various source intensities and positions. RESULTS The detector module attached to the collimator could discriminate the 192Ir point source with about 3.4% detection efficiency when including the total counts in the entire deposited energy region. As the result of collimator optimization, hole size, thickness, and length were determined to be 0.5, 0.2, and 45 mm, respectively. Accordingly, the source intensities and positions also were successfully tracked with the 3-D SPECT imaging system when the C-arm was rotated within 110° in 2 seconds. CONCLUSIONS We expect that this system can be effectively implemented for online IGABT and in vivo patient dose verification.
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Affiliation(s)
- Saerom Sung
- Department of Radiation Convergence Engineering, Yonsei University, Wonju-si, Gangwon-do, Republic of Korea
| | - Minjae Lee
- Department of Radiation Convergence Engineering, Yonsei University, Wonju-si, Gangwon-do, Republic of Korea
| | - Hyung-Joo Choi
- Department of Radiation Convergence Engineering, Yonsei University, Wonju-si, Gangwon-do, Republic of Korea
| | - Hyojun Park
- Department of Radiation Convergence Engineering, Yonsei University, Wonju-si, Gangwon-do, Republic of Korea
| | - Bo-Wi Cheon
- Department of Radiation Convergence Engineering, Yonsei University, Wonju-si, Gangwon-do, Republic of Korea
| | - Chul Hee Min
- Department of Radiation Convergence Engineering, Yonsei University, Wonju-si, Gangwon-do, Republic of Korea
| | - Yeon Soo Yeom
- Department of Radiation Convergence Engineering, Yonsei University, Wonju-si, Gangwon-do, Republic of Korea
| | - Hyemi Kim
- Department of Radiation Oncology, Wonju Severance Christian Hospital, Yonsei University Wonju College of Medicine, Wonju-si, Gangwon-do, Republic of Korea
| | - Sei Hwan You
- Department of Radiation Oncology, Wonju Severance Christian Hospital, Yonsei University Wonju College of Medicine, Wonju-si, Gangwon-do, Republic of Korea
| | - Hyun Joon Choi
- Department of Radiation Oncology, Wonju Severance Christian Hospital, Yonsei University Wonju College of Medicine, Wonju-si, Gangwon-do, Republic of Korea.
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11
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Vasyltsiv R, Qian X, Xu Z, Ryu S, Zhao W, Howansky A. Feasibility of 4D HDR brachytherapy source tracking using x-ray tomosynthesis: Monte Carlo investigation. Med Phys 2023; 50:4695-4709. [PMID: 37402139 DOI: 10.1002/mp.16579] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2023] [Revised: 05/16/2023] [Accepted: 06/11/2023] [Indexed: 07/05/2023] Open
Abstract
PURPOSE High dose rate (HDR) brachytherapy rapidly delivers dose to targets with steep dose gradients. This treatment method must adhere to prescribed treatment plans with high spatiotemporal accuracy and precision, as failure to do so may degrade clinical outcomes. One approach to achieving this goal is to develop imaging techniques to track HDR sources in vivo in reference to surrounding anatomy. This work investigates the feasibility of using an isocentric C-arm x-ray imager and tomosynthesis methods to track Ir-192 HDR brachytherapy sources in vivo over time (4D). METHODS A tomosynthesis imaging workflow was proposed and its achievable source detectability, localization accuracy, and spatiotemporal resolution were investigated in silico. An anthropomorphic female XCAT phantom was modified to include a vaginal cylinder applicator and Ir-192 HDR source (0.5 × 0.5 × 5.0 mm3 ), and the workflow was carried out using the MC-GPU Monte Carlo image simulation platform. Source detectability was characterized using the reconstructed source signal-difference-to-noise-ratio (SDNR), localization accuracy by the absolute 3D error in its measured centroid location, and spatiotemporal resolution by the full-width-at-half-maximum (FWHM) of line profiles through the source in each spatial dimension considering a maximum C-arm angular velocity of 30° per second. The dependence of these parameters on acquisition angular range (θtot = 0°-90°), number of views, angular increment between views (Δθ = 0°-15°), and volumetric constraints imposed in reconstruction was evaluated. Organ voxel doses were tallied to derive the workflow's attributable effective dose. RESULTS The HDR source was readily detected and its centroid was accurately localized with the proposed workflow and method (SDNR: 10-40, 3D error: 0-0.144 mm). Tradeoffs were demonstrated for various combinations of image acquisition parameters; namely, increasing the tomosynthesis acquisition angular range improved resolution in the depth-encoded direction, for example from 2.5 mm to 1.2 mm between θtot = 30o and θtot = 90o , at the cost of increasing acquisition time from 1 to 3 s. The best-performing acquisition parameters (θtot = 90o , Δθ = 1°) yielded no centroid localization error, and achieved submillimeter source resolution (0.57 × 1.21 × 5.04 mm3 apparent source dimensions, FWHM). The total effective dose for the workflow was 263 µSv for its required pre-treatment imaging component and 7.59 µSv per mid-treatment acquisition thereafter, which is comparable to common diagnostic radiology exams. CONCLUSIONS A system and method for tracking HDR brachytherapy sources in vivo using C-arm tomosynthesis was proposed and its performance investigated in silico. Tradeoffs in source conspicuity, localization accuracy, spatiotemporal resolution, and dose were determined. The results suggest this approach is feasible for localizing an Ir-192 HDR source in vivo with submillimeter spatial resolution, 1-3 second temporal resolution and minimal additional dose burden.
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Affiliation(s)
- Roman Vasyltsiv
- Department of Radiology, Stony Brook University, Health Sciences Center L4-120, Stony Brook, New York, USA
| | - Xin Qian
- Department of Radiation Oncology, Stony Brook University, Health Sciences Center L2, Stony Brook, New York, USA
| | - Zhigang Xu
- Department of Radiation Oncology, Stony Brook University, Health Sciences Center L2, Stony Brook, New York, USA
| | - Samuel Ryu
- Department of Radiation Oncology, Stony Brook University, Health Sciences Center L2, Stony Brook, New York, USA
| | - Wei Zhao
- Department of Radiology, Stony Brook University, Health Sciences Center L4-120, Stony Brook, New York, USA
| | - Adrian Howansky
- Department of Radiology, Stony Brook University, Health Sciences Center L4-120, Stony Brook, New York, USA
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12
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Jonušas J, Patasius A, Trakymas M, Venius J, Janulionis E, Smailyte G, Kincius M. Efficacy of focal high-dose-rate brachytherapy in the treatment of patients diagnosed with low or favourable: intermediate-risk prostate cancer-a protocol for a randomised controlled trial. BMJ Open 2023; 13:e070020. [PMID: 37197816 DOI: 10.1136/bmjopen-2022-070020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 05/19/2023] Open
Abstract
INTRODUCTION Prostate cancer (PCa) is men's second most predominant cancer worldwide. Because the prostate-specific antigen test is used in diagnostics, PCa is more often diagnosed in the early stages, making radical treatment of the disease possible. However, it is estimated that over a million men worldwide suffer from radical treatment-related complications. Thus, focal treatment has been proposed as a solution, which aims to destroy the predominant lesson that determines the progression of the disease. The main objective of our study is to compare the quality of life and efficacy of patients diagnosed with PCa before and after the treatment with focal high-dose-rate brachytherapy and to compare results with focal low-dose-rate brachytherapy and active surveillance. METHODS AND ANALYSIS 150 patients diagnosed with low-risk or favourable intermediate-risk PCa who meet the inclusion criteria will be enrolled in the study. Patients are going to be randomly assigned to the study groups: focal high-dose-rate brachytherapy (group 1), focal low-dose-rate brachytherapy (group 2) and active surveillance (group 3). The study's primary outcomes are quality of life after the procedure and time without biochemical disease recurrence. The secondary outcomes are early and late genitourinary and gastrointestinal reactions after the focal high-dose and low-dose-rate brachytherapies and evaluation of the importance and significance of in vivo dosimetry used for high-dose-rate brachytherapy. ETHICS AND DISSEMINATION Bioethics committee approval was obtained before this study. The trial results will be published in peer-reviewed journals and at conferences. TRIAL REGISTRATION NUMBER Vilnius regional bioethics committee; approval ID 2022/6-1438-911.
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Affiliation(s)
- Justinas Jonušas
- Clinic of Hematology and Oncology, Institute of Clinical Medicine, Faculty of Medicine, Vilnius University, Vilnius, Lithuania
- Laboratory of Cancer Epidemiology, National Cancer Institute, Vilnius, Lithuania
| | - Ausvydas Patasius
- Laboratory of Cancer Epidemiology, National Cancer Institute, Vilnius, Lithuania
- Institute of Health Sciences, Vilnius University Faculty of Medicine, Vilnius, Lithuania
| | - Mantas Trakymas
- Department of Radiology, National Cancer Institute, Vilnius, Lithuania
| | - Jonas Venius
- Medical Physics Department, National Cancer Institute, Vilnius, Lithuania
- Laboratory of Biomedical Physics, National Cancer Institute, Vilnius, Lithuania
| | | | - Giedre Smailyte
- Laboratory of Cancer Epidemiology, National Cancer Institute, Vilnius, Lithuania
- Institute of Health Sciences, Vilnius University Faculty of Medicine, Vilnius, Lithuania
| | - Marius Kincius
- Department of Oncourology, National Cancer Institute, Vilnius, Lithuania
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13
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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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14
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Beaulieu L, Rivard MJ. Brachytherapy evolution as seen today. Med Phys 2023. [PMID: 36773303 DOI: 10.1002/mp.16285] [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: 11/02/2022] [Accepted: 02/03/2023] [Indexed: 02/12/2023] Open
Abstract
While brachytherapy is the oldest form of radiation therapy, it is also a very exciting field from both physics and clinical perspectives. From the physics standpoint, brachytherapy dosimetry is largely being governed by the inverse-square law, leading to an unparalleled dose deposition kernel (dose emitted by a seed or single dwell position), even compared to proton or heavy-ion beamlets. There is slightly more dose beyond the central deposition point, but comparatively very little prior to it, that is, little or no entrance dose! It is easy to sum multiple dwell positions that cover a tumor, and the intensity can be modulated quite effectively using dwell times. From a clinical perspective, what sets brachytherapy apart from other intraoperative modalities (e.g., laser, radiofrequency, cryogenic) is our ability to precisely calculate the energy deposited across the relevant patient geometry, anticipate the effect from known dose-outcome relationships, and deliver that energy with exquisite control and selectively to the target volume while sparing organs at risks. This targeting ability has improved substantially over the last two decades. It is built upon key foundational elements, many of which stem from the research and development within our medical physics community. This article provides an overview of these elements that combine to make brachytherapy a successful and developing radiotherapy modality.
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Affiliation(s)
- Luc Beaulieu
- Centre Intrégé de Cancérologie et Axe oncologie du Centre de recherche du CHU de Québec, CHU de Québec, Québec, Québec, Canada.,Département de Physique, de Génie Physique et d'Optique et Centre de Recherche sur le Cancer, Université Laval, Québec, Canada
| | - Mark J Rivard
- Department of Radiation Oncology, Alpert Medical School of Brown University, Rhode Island Hospital, Providence, Rhode Island, USA
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15
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Poder J, Rivard MJ, Howie A, Carlsson Tedgren Å, Haworth A. Risk and Quality in Brachytherapy From a Technical Perspective. Clin Oncol (R Coll Radiol) 2023:S0936-6555(23)00002-X. [PMID: 36682968 DOI: 10.1016/j.clon.2023.01.001] [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: 10/03/2022] [Revised: 11/23/2022] [Accepted: 01/04/2023] [Indexed: 01/15/2023]
Abstract
AIMS To provide an overview of the history of incidents in brachytherapy and to describe the pillars in place to ensure that medical physicists deliver high-quality brachytherapy. MATERIALS AND METHODS A review of the literature was carried out to identify reported incidents in brachytherapy, together with an evaluation of the structures and processes in place to ensure that medical physicists deliver high-quality brachytherapy. In particular, the role of education and training, the use of process and technical quality assurance and the role of international guidelines are discussed. RESULTS There are many human factors in brachytherapy procedures that introduce additional risks into the process. Most of the reported incidents in the literature are related to human factors. Brachytherapy-related education and training initiatives are in place at the societal and departmental level for medical physicists. Additionally, medical physicists have developed process and technical quality assurance procedures, together with international guidelines and protocols. Education and training initiatives, together with quality assurance procedures and international guidelines may reduce the risk of human factors in brachytherapy. CONCLUSION Through application of the three pillars (education and training; process control and technical quality assurance; international guidelines), medical physicists will continue to minimise risk and deliver high-quality brachytherapy treatments.
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Affiliation(s)
- J Poder
- Department of Radiation Oncology, St George Cancer Care Centre, Kogarah, New South Wales, Australia; School of Physics, University of Sydney, Camperdown, New South Wales, Australia; Centre for Medical Radiation Physics, University of Wollongong, Wollongong, New South Wales, Australia.
| | - M J Rivard
- Department of Radiation Oncology, Alpert Medical School of Brown University, Providence, RI, USA
| | - A Howie
- Department of Radiation Oncology, St George Cancer Care Centre, Kogarah, New South Wales, Australia
| | - Å Carlsson Tedgren
- Department of Health, Medicine and Caring Sciences (HMV), Radiation Physics, Linköping University, Linköping, Sweden; Medical Radiation Physics and Nuclear Medicine, The Karolinska University Hospital, Stockholm, Sweden; Department of Oncology Pathology, The Karolinska Institute, Stockholm, Sweden
| | - A Haworth
- School of Physics, University of Sydney, Camperdown, New South Wales, Australia
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16
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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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17
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Investigation of in vivo source tracking error thresholds for interstitial and intra-cavitary high-dose-rate cervical brachytherapy. J Contemp Brachytherapy 2022; 14:568-581. [PMID: 36819472 PMCID: PMC9924149 DOI: 10.5114/jcb.2022.123977] [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: 09/16/2022] [Accepted: 12/21/2022] [Indexed: 01/18/2023] Open
Abstract
Purpose The purpose of this study was to determine a comprehensive in vivo source tracking error thresholds in high-dose-rate (HDR) brachytherapy for cervical cancer. Achieving this enables the definition of an action level for imminent in vivo source tracking technologies and treatment monitoring devices, preventing clinically relevant changes to the applied dose. Material and methods Retrospective HDR interstitial (n = 10) and intra-cavitary (n = 20) cervical brachytherapy patients were randomly selected to determine the feasibility of implementing in vivo source tracking error thresholds. A script was developed to displace all dwell positions in each treatment plan, along all major axes from their original position. Dose-volume histogram (DVH) indices were calculated without re-optimization of modified plans to determine the appropriate in vivo source tracking error thresholds in each direction. Results In vivo source tracking error thresholds were directionally dependent; the smallest were found to be 2 mm in the anterior and posterior directions for both interstitial and intra-cavitary treatments. High-risk clinical treatment volume (HR-CTV) coverage was significantly impacted by displacements of 4 to 5 mm along each axis. Critically, there was a large variation in DVH metrics with displacement due to change in dwell weightings and patient anatomy. Conclusions Determining the dosimetric impact of dwell position displacement provides a clinical benchmark for the development of pre-treatment verification devices and an action level for real-time treatment monitoring. It was established that an in vivo source tracking error threshold needs to be patient-specific. In vivo source tracking error thresholds should be determined for each patient, and can be conducted with extension of the method established in this work.
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18
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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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19
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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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20
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Koprivec D, Rosenfeld A, Cutajar D, Petasecca M, Howie A, Bucci J, Poder J. Feasibility of online adaptive HDR prostate brachytherapy: A novel treatment concept. Brachytherapy 2022; 21:943-955. [PMID: 36068155 DOI: 10.1016/j.brachy.2022.07.011] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Revised: 07/18/2022] [Accepted: 07/30/2022] [Indexed: 12/14/2022]
Abstract
PURPOSE The purpose of this study was to determine the feasibility of online adaptive transrectal ultrasound (TRUS)-based high-dose-rate prostate brachytherapy (HDRPBT) through retrospective simulation of source positioning and catheter swap errors on patient treatment plans. METHOD Source positioning errors (catheter shifts in 1 mm increments in the cranial/caudal, anterior/posterior, and medial/lateral directions up to ±6 mm) and catheter swap errors (between the most and least heavily weighted) were introduced retrospectively into DICOM treatment plans of 20 patients that previously received TRUS HDRPBT. Dose volume histogram (DVH) indices were monitored as errors were introduced sequentially into individual catheters, simulating potential errors throughout treatment. Whenever DVH indices were outside institution thresholds: prostate V100% <95%, urethra D0.1cc >118% and rectum Dmax >80%, the plan was adapted using remaining catheters (i.e., simulating previous catheters as previously delivered). The final DVH indices were recorded. RESULTS Prostate coverage (V100% >95%) could be maintained for source position errors up to 6 mm through online plan adaptation. The source position error at which the urethra D0.1cc and rectum Dmax was able to return to clinically acceptable levels using online adaptation varied between 6 mm to 1 mm, depending on the direction of the source position error and patient anatomy. After introduction of catheter swap errors to patient plans, prostate V100% was recoverable using online adaptation to near original plan characteristics. Urethra D0.1cc and rectum Dmax showed less recoverability. CONCLUSION Online adaptive HDRPBT maintains the prostate V100% to clinically acceptable values for majority of directional shifts. However, the current online adaptive method may not correct for source position errors near organs at risk.
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Affiliation(s)
- Dylan Koprivec
- Centre for Medical Radiation Physics, University of Wollongong, Wollongong, NSW, Australia.
| | - Anatoly Rosenfeld
- Centre for Medical Radiation Physics, University of Wollongong, Wollongong, NSW, Australia
| | - Dean Cutajar
- Centre for Medical Radiation Physics, University of Wollongong, Wollongong, NSW, Australia; St George Cancer Care Centre, Kogarah, NSW, Australia
| | - Marco Petasecca
- Centre for Medical Radiation Physics, University of Wollongong, Wollongong, NSW, Australia
| | - Andrew Howie
- St George Cancer Care Centre, Kogarah, NSW, Australia
| | - Joseph Bucci
- St George Cancer Care Centre, Kogarah, NSW, Australia
| | - Joel Poder
- Centre for Medical Radiation Physics, University of Wollongong, Wollongong, NSW, Australia; St George Cancer Care Centre, Kogarah, NSW, Australia
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21
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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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22
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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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23
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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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24
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Ab Shukor NS, Musarudin M, Abdullah R, Abd Aziz MZ. Monte Carlo simulation of HDR Brachytherapy dosimetric parameters in different mediums. Radiat Phys Chem Oxf Engl 1993 2022. [DOI: 10.1016/j.radphyschem.2022.110227] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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25
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Kaveckyte V, Jørgensen EB, Kertzscher G, Johansen JG, Tedgren ÅC. Monte Carlo characterization of high atomic number inorganic scintillators for in vivo dosimetry in 192 Ir brachytherapy. Med Phys 2022; 49:4715-4730. [PMID: 35443079 DOI: 10.1002/mp.15674] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Revised: 03/01/2022] [Accepted: 04/06/2022] [Indexed: 11/05/2022] Open
Abstract
BACKGROUND There is increased interest in vivo dosimetry for 192 Ir brachytherapy (BT) treatments using high atomic number (Z) inorganic scintillators. Their high light output enables construction of small detectors with negligible stem effect and simple readout electronics. Experimental determination of absorbed-dose energy dependence of detectors relative to water is prevalent, but it can be prone to high detector positioning uncertainties and does not allow for decoupling of absorbed-dose energy dependence from other factors affecting detector response. PURPOSE To investigate which measurement conditions and detector properties could affect their absorbed-dose energy dependence in BT in vivo dosimetry. METHODS We used a general-purpose MC code penelope for the characterization of high-Z inorganic scintillators with the focus on ZnSe (Z¯=32). Two other promising media CsI (Z¯=54) and Al2 O3 (Z¯=11) were included for comparison in selected scenarios. We determined absorbed-dose energy dependence of crystals relative to water under different scatter conditions (calibration phantom 12 × 12 × 30 cm3 , characterization phantoms 20 × 20 × 20 cm3 , 30 × 30 × 30 cm3 , 40 × 40 × 40 cm3 , and patient-like elliptic phantom 40 × 30 × 25 cm3 ). To mimic irradiation conditions during prostate treatments, we evaluated whether the presence of pelvic bones and calcifications affect ZnSe response. ZnSe detector design influence was also investigated. RESULTS In contrast to low-Z organic and medium-Z inorganic scintillators, ZnSe and CsI media have substantially greater absorbed-dose energy dependence relative to water. The response was phantom-size dependent and changed by 11 % between limited- and full-scatter conditions for ZnSe, but not for Al2 O3 . For a given phantom size, a part of the absorbed-dose energy dependence of ZnSe is caused not due to in-phantom scatter but due to source anisotropy. Thus, the absorbed-dose energy dependence of high-Z scintillators is a function of not only the radial distance but also the polar angle. Pelvic bones did not affect ZnSe response, whereas large and intermediate size calcifications reduced it by 9 % and 5 %, respectively, when placed midway between the source and the detector. CONCLUSIONS Unlike currently prevalent low- and medium-Z scintillators, high-Z crystals are sensitive to characterization and in vivo measurement conditions. However, good agreement between MC data for ZnSe in the present study and experimental data for ZnSe:O by Jørgensen et al (2021) suggest that detector signal is proportional to the average absorbed dose to the detector cavity. This enables an easy correction for non-TG43-like scenarios (e.g., patient sizes and calcifications) through MC simulations. Information that should be provided to the clinic by the detector vendors. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Vaiva Kaveckyte
- Department of Health, Medicine and Caring Sciences, Linköping University, Linköping, SE-581 85, Sweden
| | - Erik B Jørgensen
- Department of Clinical Medicine, Aarhus University, Aarhus, DK-8000, Denmark.,Department of Oncology, Aarhus University Hospital, Aarhus, DK-8000, Denmark
| | - Gustavo Kertzscher
- Department of Oncology, Aarhus University Hospital, Aarhus, DK-8000, Denmark
| | - Jacob G Johansen
- Department of Clinical Medicine, Aarhus University, Aarhus, DK-8000, Denmark.,Department of Oncology, Aarhus University Hospital, Aarhus, DK-8000, Denmark
| | - Åsa Carlsson Tedgren
- Department of Health, Medicine and Caring Sciences, Linköping University, Linköping, SE-581 85, Sweden.,Department of Medical Radiation Physics and Nuclear Medicine, Karolinska University Hospital, Stockholm, SE-171 76, Sweden.,Department of Oncology-Pathology, Karolinska Institute, Stockholm, SE-171 76, Sweden
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Lekatou A, Peppa V, Karaiskos P, Pantelis E, Papagiannis P. On the potential of 2D ion chamber arrays for high-dose rate remote afterloading brachytherapy quality assurance. Phys Med Biol 2022; 67. [PMID: 35334474 DOI: 10.1088/1361-6560/ac612d] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2021] [Accepted: 03/25/2022] [Indexed: 01/08/2023]
Abstract
Objective. To investigate the potential of 2D ion chamber arrays to serve as a standalone tool for the verification of source strength, positioning and dwell time, within the framework of192Ir high-dose rate brachytherapy device quality assurance (QA).Approach.A commercially available ion chamber array was used. Fitting of a 2D Lorentzian peak function to experimental data from a multiple source dwell position irradiation on a frame-by-frame basis, facilitated tracking of the source center orthogonal projection on the array plane. For source air kerma strength verification, Monte Carlo simulation was employed to obtain a chamber array- and source-specific correction factor of calibration with a 6 MV photon beam. This factor converted the signal measured by each ion chamber element to air kerma in free space. A source positioning correction was also applied to lift potential geometry mismatch between experiment and Monte Carlo simulation.Main results.Spatial and temporal accuracy of source movement was verified within 0.5 mm and 0.02 s, respectively, in compliance with the test endpoints recommended by international professional societies. The source air kerma strength was verified experimentally within method uncertainties estimated as 1.44% (k = 1). The source positioning correction method employed did not introduce bias to experimental results of irradiations where source positioning was accurate. Development of a custom jig attachable to the chamber array for accurate and reproducible experimental set up would improve testing accuracy and obviate the need for source positioning correction in air kerma strength verification.Significance.Delivery of a single irradiation plan, optimized based on results of this work, to a 2D ion chamber array can be used for concurrent testing of source position, dwell time and air kerma strength, and the procedure can be expedited through automation. Chamber arrays merit further study in treatment planning QA and real time,in vivodose verification.
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Affiliation(s)
- Aristea Lekatou
- Medical Physics Laboratory, Department of Medicine, National and Kapodistrian University of Athens, 75 Mikras Asias, 11527 Athens, Greece
| | - Vasiliki Peppa
- Medical Physics Laboratory, Department of Medicine, National and Kapodistrian University of Athens, 75 Mikras Asias, 11527 Athens, Greece
| | - Pantelis Karaiskos
- Medical Physics Laboratory, Department of Medicine, National and Kapodistrian University of Athens, 75 Mikras Asias, 11527 Athens, Greece
| | - Evangelos Pantelis
- Medical Physics Laboratory, Department of Medicine, National and Kapodistrian University of Athens, 75 Mikras Asias, 11527 Athens, Greece
| | - Panagiotis Papagiannis
- Medical Physics Laboratory, Department of Medicine, National and Kapodistrian University of Athens, 75 Mikras Asias, 11527 Athens, Greece
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Poder J, Koprivec D, Dookie Y, Howie A, Cutajar D, Damato AL, Côté N, Petasecca M, Bucci J, Rosenfeld A. HDR prostate brachytherapy plan robustness and its effect on in-vivo source tracking error thresholds: A multi-institutional study. Med Phys 2022; 49:3529-3537. [PMID: 35388456 PMCID: PMC9322430 DOI: 10.1002/mp.15658] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2021] [Revised: 03/15/2022] [Accepted: 03/17/2022] [Indexed: 11/09/2022] Open
Abstract
PURPOSE The purpose of this study was to examine the effect of departmental planning techniques on appropriate in-vivo source tracking error thresholds for high dose rate (HDR) prostate brachytherapy (BT) treatments, and to determine if a single in-vivo source tracking error threshold would be appropriate for the same patient anatomy. METHOD The prostate, rectum, and urethra, was contoured on a single patient trans-rectal ultrasound (TRUS) dataset. Anonymised DICOM files were disseminated to 16 departments who created an HDR prostate BT treatment plan on the dataset with a prescription dose of 15 Gy in a single fraction. Departments were asked to follow their own local treatment planning guidelines. Source positioning errors were then simulated in the 16 treatment plans and the effect on dose-volume histogram (DVH) indices calculated. Change in DVH indices were used to determine appropriate in-vivo source tracking error thresholds. Plans were considered to require intervention if the following DVH conditions occurred: prostate V100% < 90%, urethra D0.1cc > 118%, and rectum Dmax > 80%. RESULTS There was wide variation in appropriate in-vivo source tracking error thresholds amongst the 16 participating departments, ranging from 1 - 6 mm. Appropriate in-vivo source tracking error thresholds were also found to depend on the direction of the source positioning error and the end-point. A robustness parameter was derived, and found to correlate with the sensitivity of plans to source positioning errors. CONCLUSION A single HDR prostate BT in-vivo source tracking error threshold cannot be applied across multiple departments, even for the same patient anatomy. The burden on in-vivo source tracking devices may be eased through improving HDR prostate BT plan robustness during the plan optimisation phase. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Joel Poder
- Department of Radiation Oncology, St George Cancer Care Centre, Kogarah, NSW, Australia.,Centre for Medical Radiation Physics, University of Wollongong, Wollongong, NSW, Australia
| | - Dylan Koprivec
- Centre for Medical Radiation Physics, University of Wollongong, Wollongong, NSW, Australia
| | - Yashiv Dookie
- Centre for Medical Radiation Physics, University of Wollongong, Wollongong, NSW, Australia
| | - Andrew Howie
- Department of Radiation Oncology, St George Cancer Care Centre, Kogarah, NSW, Australia
| | - Dean Cutajar
- Department of Radiation Oncology, St George Cancer Care Centre, Kogarah, NSW, Australia.,Centre for Medical Radiation Physics, University of Wollongong, Wollongong, NSW, Australia
| | - Antonio L Damato
- Department of Medical Physics, Memorial Sloan Kettering Cancer Centre, New York, NY, USA
| | - Nicolas Côté
- Department of Medical Physics, Memorial Sloan Kettering Cancer Centre, New York, NY, USA
| | - Marco Petasecca
- Centre for Medical Radiation Physics, University of Wollongong, Wollongong, NSW, Australia
| | - Joseph Bucci
- Department of Radiation Oncology, St George Cancer Care Centre, Kogarah, NSW, Australia
| | - Anatoly Rosenfeld
- Centre for Medical Radiation Physics, University of Wollongong, Wollongong, NSW, Australia
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Jørgensen EB, Buus S, Bentzen L, Hokland SB, Rylander S, Kertzscher G, Beddar S, Tanderup K, Johansen JG. 3D dose reconstruction based on in vivo dosimetry for determining the dosimetric impact of geometric variations in high-dose-rate prostate brachytherapy. Radiother Oncol 2022; 171:62-68. [PMID: 35033604 DOI: 10.1016/j.radonc.2022.01.006] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Revised: 12/30/2021] [Accepted: 01/04/2022] [Indexed: 11/16/2022]
Abstract
INTRODUCTION In vivo dosimetry (IVD) can be used for source tracking (ST), i.e., estimating source positions, during brachytherapy. The aim of this study was to exploit IVD-based ST to perform 3D dose reconstruction for high-dose-rate prostate brachytherapy and to evaluate the robustness of the treatments against observed geometric variations. MATERIALS AND METHODS Twenty-three fractions of high-dose-rate prostate brachytherapy were analysed. The treatment planning was based on MRI. Time-resolved IVD was performed using a fibre-coupled scintillator. ST was retrospectively performed using the IVD measurements. The ST identified 2D positional shifts of each treatment catheter and thereby inferred updated source positions. For each fraction, the dose was recalculated based on the source-tracked catheter positions and compared with the original plan dose using differences in dose volume histogram indices. RESULTS Of 352 treatment catheters, 344 had shifts of less than 5 mm. Shifts between 5 and 10 mm were observed for 3 catheters, and shifts greater than 10 mm for 2 catheters. The ST failed for 3 catheters. The maximum relative difference in clinical target volume (prostate + 3 mm isotropic margin) D90% was 5%. In one fraction, the bladder D2cm3 dose increased by 18% (1.4Gy) due to a single source position being inside the bladder rather than nearby as planned. The max increase in urethra dose was 1.5Gy (15%). CONCLUSION IVD-based 3D dose reconstruction for high-dose-rate prostate brachytherapy is feasible. The dosimetric impact of the observed catheter shifts was limited. Dose reconstruction can therefore aid in determining the dosimetric impact of geometric variations and errors in brachytherapy.
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Affiliation(s)
- Erik B Jørgensen
- Department of Clinical Medicine, Aarhus University, Aarhus, Denmark.
| | - Simon Buus
- Department of Oncology, Aarhus University Hospital, Aarhus, Denmark
| | - Lise Bentzen
- Department of Clinical Medicine, Aarhus University, Aarhus, Denmark; Department of Oncology, Aarhus University Hospital, Aarhus, Denmark
| | | | - Susanne Rylander
- Department of Oncology, Aarhus University Hospital, Aarhus, Denmark
| | | | - Sam Beddar
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas, United States
| | - Kari Tanderup
- Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Jacob G Johansen
- Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
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Henry A, Pieters BR, André Siebert F, Hoskin P. GEC-ESTRO ACROP prostate brachytherapy guidelines. Radiother Oncol 2022; 167:244-251. [PMID: 34999134 DOI: 10.1016/j.radonc.2021.12.047] [Citation(s) in RCA: 31] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Accepted: 12/31/2021] [Indexed: 02/07/2023]
Abstract
This is an evidence-based guideline for prostate brachytherapy. Throughout levels of evidence quoted are those from the Oxford Centre for Evidence based Medicine (https://www.cebm.ox.ac.uk/resources/levels-of-evidence/oxford-centre-for-evidence-based-medicine-levels-of-evidence-march-2009). Prostate interstitial brachytherapy using either permanent or temporary implantation is an established and evolving treatment technique for non-metastatic prostate cancer. Permanent brachytherapy uses Low Dose Rate (LDR) sources, most commonly I-125, emitting photon radiation over months. Temporary brachytherapy involves first placing catheters within the prostate and, on confirmation of accurate positioning, temporarily introducing the radioactive source, generally High Dose Rate (HDR) radioactive sources of Ir-192 or less commonly Co-60. Pulsed dose rate (PDR) brachytherapy has also been used for prostate cancer [1] but few centres have adopted this approach. Previous GEC ESTRO recommendations have considered LDR and HDR separately [2-4] but as there is considerable overlap, this paper provides updated guidance for both treatment techniques. Prostate brachytherapy allows safe radiation dose escalation beyond that achieved using external beam radiotherapy alone as it has greater conformity around the prostate, sparing surrounding rectum, bladder, and penile bulb. In addition there are fewer issues with changes in prostate position during treatment delivery. Systematic review and randomised trials using both techniques as boost treatments demonstrate improved PSA control when compared to external beam radiotherapy alone [5-7].
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Affiliation(s)
- Ann Henry
- St James University Hospital, Leeds, UK
| | - Bradley R Pieters
- Amsterdam University Medical Centers, University of Amsterdam, Amsterdam, The Netherlands
| | - Frank André Siebert
- University of Kiel/University Hospital Schleswig-Holstein Campus Kiel, Germany
| | - Peter Hoskin
- Mount Vernon Cancer Centre, Northwood, UK; University of Manchester, Manchester, UK.
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Hanlon MD, Smith RL, Franich RD. MaxiCalc: A tool for online dosimetric evaluation of source-tracking based treatment verification in HDR brachytherapy. Phys Med 2022; 94:58-64. [PMID: 34998133 DOI: 10.1016/j.ejmp.2021.12.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/16/2021] [Revised: 12/09/2021] [Accepted: 12/16/2021] [Indexed: 01/11/2023] Open
Abstract
PURPOSE Source tracking is becoming a more widely used approach in HDR brachytherapy treatment verification. While it provides a sensitive method to detect deviations from the treatment plan during delivery, it does not show the clinical significance of any detected changes. By incorporating a tool that calculates volumetric doses and DVH indices from measurements, source tracking systems can be expanded to assess dosimetric significance of any deviations from the plan. METHODS The source tracking dose calculation tool, MaxiCalc, was developed in MATLAB. Validation was performed by comparing doses and DVH indices calculated in MaxiCalc to those calculated by the clinical TPS, for several test plans and 10 clinical plans. Clinical implementation was demonstrated by calculating volumetric doses from a clinical source tracking event. RESULTS MaxiCalc showed excellent agreement with the clinical TPS for point and volumetric doses (mean difference < 0.01% and 0.1% respectively). MaxiCalc calculates dosimetrically equivalent plans to the TPS with agreement < 0.3% for all DVH indices except PTV V200%. Small differences seen for the clinical source tracking event were consistent with the known tracking uncertainties enabling them to be quantified for clinical decision making. Calculations are fast, enabling real-time use. CONCLUSIONS MaxiCalc is an independent tool that calculates doses and DVH indices from dwells measured with any clinical HDR brachytherapy source tracking system. This extends the capabilities of source tracking systems from determining discrepancies in positions or times during delivery to assessing the dosimetric impact of any detected deviations, allowing for more comprehensive treatment verification and evaluation.
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Affiliation(s)
- Maximilian D Hanlon
- School of Science, RMIT University, Melbourne, Australia; Alfred Health Radiation Oncology, The Alfred, Melbourne, Australia.
| | - Ryan L Smith
- School of Science, RMIT University, Melbourne, Australia; Alfred Health Radiation Oncology, The Alfred, Melbourne, Australia
| | - Rick D Franich
- School of Science, RMIT University, Melbourne, Australia
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31
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Ab Shukor NS, Musarudin M, Abdullah R, Abd Aziz MZ. Monte Carlo Simulation of Hdr Brachytherapy Dosimetric Parameters in Different Mediums. SSRN ELECTRONIC JOURNAL 2022. [DOI: 10.2139/ssrn.4048875] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/01/2023]
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32
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Biological Planning of Radiation Dose Based on In Vivo Dosimetry for Postoperative Vaginal-Cuff HDR Interventional Radiotherapy (Brachytherapy). Biomedicines 2021; 9:biomedicines9111629. [PMID: 34829858 PMCID: PMC8615499 DOI: 10.3390/biomedicines9111629] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2021] [Revised: 10/28/2021] [Accepted: 11/04/2021] [Indexed: 12/24/2022] Open
Abstract
(1) Background: Postoperative vaginal-cuff HDR interventional radiotherapy (brachytherapy) is a standard treatment in early-stage endometrial cancer. This study reports the effect of in vivo dosimetry-based biological planning for two different fractionation schedules on the treatment-related toxicities. (2) Methods: 121 patients were treated. Group A (82) received 21 Gy in three fractions. Group B (39) received 20 Gy in four fractions. The dose was prescribed at a 5 mm depth or to the applicator surface according to the distance between the applicator and the rectum. In vivo dosimetry measured the dose of the rectum and/or urinary bladder. With a high measured dose, the dose prescription was changed from a 5 mm depth to the applicator surface. (3) Results: The median age was 66 years with 58.8 months mean follow-up. The dose prescription was changed in 20.7% of group A and in 41% of group B. Most toxicities were grade 1–2. Acute urinary toxicities were significantly higher in group A. The rates of acute and late urinary toxicities were significantly higher with a mean bladder dose/fraction of >2.5 Gy and a total bladder dose of >7.5 Gy. One patient had a vaginal recurrence. (4) Conclusions: Both schedules have excellent local control and acceptable rates of toxicities. Using in vivo dosimetry-based biological planning yielded an acceptable dose to the bladder and rectum.
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33
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Fonseca GP, Voncken R, Hermans J, Verhaegen F. Time-resolved QA and brachytherapy applicator commissioning: Towards the clinical implementation. Brachytherapy 2021; 21:128-137. [PMID: 34657801 DOI: 10.1016/j.brachy.2021.08.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Revised: 07/09/2021] [Accepted: 08/09/2021] [Indexed: 01/22/2023]
Abstract
PURPOSE Brachytherapy has a busy workflow relying on manual steps to ensure accurate delivery of the treatment. Systematic treatment errors have been reported due to faulty equipment, inadequate quality assurance (QA) and applicator commissioning methods. This study describes the use of a novel method, the Iridium Imaging System for QA (IrIS - QA), to automate and improve the applicator commissioning for HDR 192Ir brachytherapy. METHODS AND MATERIALS A 3D printed holder attached to an Imaging Panel (IP) has been developed to: (1) acquire a high-definition projection of the applicator using the gamma rays of the 192Ir source for imaging; (2) Track the source within the applicator verifying in a time-resolved manner the dwell positions and dwell times with a high resolution. Results obtained for two applicator models are described in this manuscript. RESULTS IrIS-QA is capable of measuring the dwell times with an accuracy better than 0.1 s and interdwell distances with submillimetre precision. The applicators tested in the study showed good agreement between planned and delivered dwell times and positions, with mean and maximum dwell position deviations below 0.5 mm and 1.3 mm, respectively. Dwell time measurements showed agreement superior to 0.05 s except for the first dwell position for which up to 0.15 s differences were observed. CONCLUSIONS IrIS-QA is a compact system that includes many features necessary to improve the accuracy and efficiency of applicator commissioning and daily QA. No commercial system exists with similar capabilities. IrIS-QA is intended to replace current clinical procedures using film dosimetry.
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Affiliation(s)
- Gabriel P Fonseca
- Department of Radiation Oncology (MAASTRO), GROW School for Oncology and Developmental Biology, Maastricht University Medical Centre, Maastricht, the Netherlands.
| | - Robert Voncken
- Department of Radiation Oncology (MAASTRO), GROW School for Oncology and Developmental Biology, Maastricht University Medical Centre, Maastricht, the Netherlands
| | - Joep Hermans
- Department of Radiation Oncology (MAASTRO), GROW School for Oncology and Developmental Biology, Maastricht University Medical Centre, Maastricht, the Netherlands
| | - Frank Verhaegen
- Department of Radiation Oncology (MAASTRO), GROW School for Oncology and Developmental Biology, Maastricht University Medical Centre, Maastricht, the Netherlands
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Jørgensen EB, Johansen JG, Overgaard J, Piché-Meunier D, Tho D, Rosales HML, Tanderup K, Beaulieu L, Kertzscher G, Beddar S. A high-Z inorganic scintillator-based detector for time-resolved in vivo dosimetry during brachytherapy. Med Phys 2021; 48:7382-7398. [PMID: 34586641 DOI: 10.1002/mp.15257] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Revised: 08/08/2021] [Accepted: 09/09/2021] [Indexed: 11/11/2022] Open
Abstract
PURPOSE High-dose rate (HDR) and pulsed-dose rate (PDR) brachytherapy would benefit from an independent treatment verification system to monitor treatment delivery and to detect errors in real time. This paper characterizes and provides an uncertainty budget for a detector based on a fiber-coupled high-Z inorganic scintillator capable of performing time-resolved in vivo dosimetry during HDR and PDR brachytherapy. METHOD The detector was composed of a detector probe and an optical reader. The detector probe consisted of either a 0.5 × 0.4 × 0.4 mm3 (HDR) or a 1.0 × 0.4 × 0.4 mm3 (PDR) cuboid ZnSe:O crystal glued onto an optical-fiber cable. The outer diameter of the detector probes was 1 mm, and fit inside standard brachytherapy catheters. The signal from the detector probe was read out at 20 Hz by a photodiode and a data acquisition device inside the optical reader. In order to construct an uncertainty budget for the detector, six characteristics were determined: (1) temperature dependence of the detector probe, (2) energy dependence as a function of the probe-to-source position in 2D (determined with 2 mm resolution using a robotic arm), (3) the signal-to-noise ratio (SNR), (4) short-term stability over 8 h, and (5) long-term stability of three optical readers and four probes used for in vivo monitoring in HDR and PDR treatments over 21 months (196 treatments and 189 detector calibrations, and (6) dose-rate dependence. RESULTS The total uncertainty of the detector at a 20 mm probe-to-source distance was < 5.1% and < 5.8% for the HDR and PDR versions, respectively. Regarding the above characteristics, (1) the sensitivity of the detector decreased by an average of 1.4%/°C for detector probe temperatures varying from 22 to 37°C; (2) the energy dependence of the detector was nonlinear and depended on both probe-to-source distance and the angle between the probe and the brachytherapy source; (3) the median SNRs were 187 and 34 at a 20 mm probe-to-source distance for the HDR and PDR versions, respectively (corresponding median source activities of 4.8 and 0.56 Ci, respectively); (4) the detector response varied by 0.6% in 11 identical irradiations over 8 h; (5) the sensitivity of the four detector probes decreased systematically by 0-1.2%/100 Gy of dose delivered to the probes, and random fluctuations of 4.8% in the sensitivity were observed for the three probes used in PDR and 1.9% for the probe used in HDR; and (6) the detector response was linear with dose rate. CONCLUSION ZnSe:O detectors can be used effectively for in vivo dosimetry and with high accuracy for HDR and PDR brachytherapy applications.
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Affiliation(s)
- Erik B Jørgensen
- Health Graduate School, Aarhus University, Aarhus, Denmark.,Department of Oncology, Aarhus University Hospital, Aarhus, Denmark
| | - Jacob G Johansen
- Department of Oncology, Aarhus University Hospital, Aarhus, Denmark
| | | | - Dominique Piché-Meunier
- Département de physique-de génie physique et d'optique et Centre de recherche sur le cancer, Université Laval, Québec City, Quebec, Canada.,Département de radio-oncologie et Axe Oncologie, CHU de Québec-Université Laval, Québec City, Quebec, Canada
| | - Daline Tho
- Département de physique-de génie physique et d'optique et Centre de recherche sur le cancer, Université Laval, Québec City, Quebec, Canada.,Département de radio-oncologie et Axe Oncologie, CHU de Québec-Université Laval, Québec City, Quebec, Canada
| | - Haydee M L Rosales
- Département de physique-de génie physique et d'optique et Centre de recherche sur le cancer, Université Laval, Québec City, Quebec, Canada.,Département de radio-oncologie et Axe Oncologie, CHU de Québec-Université Laval, Québec City, Quebec, Canada
| | - Kari Tanderup
- Department of Oncology, Aarhus University Hospital, Aarhus, Denmark
| | - Luc Beaulieu
- Département de physique-de génie physique et d'optique et Centre de recherche sur le cancer, Université Laval, Québec City, Quebec, Canada.,Département de radio-oncologie et Axe Oncologie, CHU de Québec-Université Laval, Québec City, Quebec, Canada
| | - Gustavo Kertzscher
- Department of Oncology, Aarhus University Hospital, Aarhus, Denmark.,Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Sam Beddar
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
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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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Fonseca GP, van Wagenberg T, Voncken R, Podesta M, van Beveren C, van Limbergen E, Lutgens L, Vanneste B, Berbee M, Reniers B, Verhaegen F. Brachytherapy treatment verification using gamma radiation from the internal treatment source combined with an imaging panel-a phantom study. Phys Med Biol 2021; 66. [PMID: 33831856 DOI: 10.1088/1361-6560/abf605] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2021] [Accepted: 04/08/2021] [Indexed: 12/15/2022]
Abstract
Brachytherapy has an excellent clinical outcome for different treatment sites. However,in vivotreatment verification is not performed in the majority of hospitals due to the lack of proper monitoring systems. This study investigates the use of an imaging panel (IP) and the photons emitted by a high dose rate (HDR)192Ir source to track source motion and obtain some information related to the patient anatomy. The feasibility of this approach was studied by monitoring the treatment delivery to a 3D printed phantom that mimicks a prostate patient. A 3D printed phantom was designed with a template for needle insertion, a cavity ('rectum') to insert an ultrasound probe, and lateral cavities used to place tissue-equivalent materials. CT images were acquired to create HDR192Ir treatment plans with a range of dwell times, interdwell distances and needle arrangements. Treatment delivery was verified with an IP placed at several positions around the phantom using radiopaque markers on the outer surface to register acquired IP images with the planning CT. All dwell positions were identified using acquisition times ≤0.11 s (frame rates ≥ 9 fps). Interdwell distances and dwell positions (in relation to the IP) were verified with accuracy better than 0.1 cm. Radiopaque markers were visible in the acquired images and could be used for registration with CT images. Uncertainties for image registration (IP and planning CT) between 0.1 and 0.4 cm. The IP is sensitive to tissue-mimicking insert composition and showed phantom boundaries that could be used to improve treatment verification. The IP provided sufficient time and spatial resolution for real-time source tracking and allows for the registration of the planning CT and IP images. The results obtained in this study indicate that several treatment errors could be detected including swapped catheters, incorrect dwell times and dwell positions.
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Affiliation(s)
- G P Fonseca
- Department of Radiation Oncology (MAASTRO), GROW School for Oncology and Developmental Biology, Maastricht University Medical Centre+, Doctor Tanslaan 12, 6229 ET Maastricht, The Netherlands
| | - T van Wagenberg
- Department of Radiation Oncology (MAASTRO), GROW School for Oncology and Developmental Biology, Maastricht University Medical Centre+, Doctor Tanslaan 12, 6229 ET Maastricht, The Netherlands
| | - R Voncken
- Department of Radiation Oncology (MAASTRO), GROW School for Oncology and Developmental Biology, Maastricht University Medical Centre+, Doctor Tanslaan 12, 6229 ET Maastricht, The Netherlands
| | - M Podesta
- Department of Radiation Oncology (MAASTRO), GROW School for Oncology and Developmental Biology, Maastricht University Medical Centre+, Doctor Tanslaan 12, 6229 ET Maastricht, The Netherlands
| | - C van Beveren
- Department of Radiation Oncology (MAASTRO), GROW School for Oncology and Developmental Biology, Maastricht University Medical Centre+, Doctor Tanslaan 12, 6229 ET Maastricht, The Netherlands
| | - E van Limbergen
- Department of Radiation Oncology (MAASTRO), GROW School for Oncology and Developmental Biology, Maastricht University Medical Centre+, Doctor Tanslaan 12, 6229 ET Maastricht, The Netherlands
| | - L Lutgens
- Department of Radiation Oncology (MAASTRO), GROW School for Oncology and Developmental Biology, Maastricht University Medical Centre+, Doctor Tanslaan 12, 6229 ET Maastricht, The Netherlands
| | - B Vanneste
- Department of Radiation Oncology (MAASTRO), GROW School for Oncology and Developmental Biology, Maastricht University Medical Centre+, Doctor Tanslaan 12, 6229 ET Maastricht, The Netherlands
| | - M Berbee
- Department of Radiation Oncology (MAASTRO), GROW School for Oncology and Developmental Biology, Maastricht University Medical Centre+, Doctor Tanslaan 12, 6229 ET Maastricht, The Netherlands
| | - B Reniers
- Research group NuTeC, Centre for Environmental Sciences, Hasselt University, Diepenbeek, Belgium
| | - F Verhaegen
- Department of Radiation Oncology (MAASTRO), GROW School for Oncology and Developmental Biology, Maastricht University Medical Centre+, Doctor Tanslaan 12, 6229 ET Maastricht, The Netherlands
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Linares Rosales HM, Johansen JG, Kertzscher G, Tanderup K, Beaulieu L, Beddar S. 3D source tracking and error detection in HDR using two independent scintillator dosimetry systems. Med Phys 2021; 48:2095-2107. [PMID: 33222208 DOI: 10.1002/mp.14607] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2020] [Revised: 09/22/2020] [Accepted: 11/01/2020] [Indexed: 01/22/2023] Open
Abstract
PURPOSE The aim of this study is to perform three-dimensional (3D) source position reconstruction by combining in vivo dosimetry measurements from two independent detector systems. METHODS Time-resolved dosimetry was performed in a water phantom during HDR brachytherapy irradiation with 192 Ir source using two detector systems. The first was based on three plastic scintillator detectors and the second on a single inorganic crystal (CsI:Tl). Brachytherapy treatments were simulated in water under TG-43U1 conditions, including a HDR prostate plan. Treatment needles were placed in distances covering a range of source movement of 120 mm around the detectors. The distance from each dwell position to each scintillator was determined based on the measured dose rates. The three distances given by the mPSD were recalculated to a position along the catheter (z) and a distance radially away from the mPSD (xy) for each dwell position (a circumference around the mPSD). The source x, y, and z coordinates were derived from the intersection of the mPSD's circumference with the sphere around the ISD based on the distance to this detector. We evaluated the accuracy of the source position reconstruction as a function of the distance to the source, the most likely location for detector positioning within a prostate volume, as well as the capacity to detect positioning errors. RESULTS Approximately 4000 source dwell positions were tracked for eight different HDR plans. An intersection of the mPSD torus and the ISD sphere was observed in 77.2% of the dwell positions, assuming no uncertainty in the dose rate determined distance. This increased to 100% if 1σ search regions were added. However, only 73(96)% of the expected dwell positions were found within the intersection band for 1(2) σ uncertainties. The agreement between the source's reconstructed and expected positions was within 3 mm for a range of distances to the source up to 50 mm. The experiments on a HDR prostate plan, showed that by having at least one of the detectors located in the middle of the prostate volume, reduces the measurement deviations considerably compared to scenarios where the detectors were located outside of the prostate volume. The analysis showed a detection probability that, in most cases, is far from the random detection threshold. Errors of 1(2) mm can be detected in ranges of 5-25 (25-50) mm from the source, with a true detection probability rate higher than 80%, while the false probability rate is kept below 20%. CONCLUSIONS By combining two detector responses, we enabled the determination of the absolute source coordinates. The combination of the mPSD and the ISD in vivo dosimetry constitutes a promising alternative for real-time 3D source tracking in HDR brachytherapy.
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Affiliation(s)
| | - Jacob G Johansen
- Department of Oncology, Aarhus University Hospital, Aarhus C, Denmark
| | | | - Kari Tanderup
- Department of Oncology, Aarhus University Hospital, Aarhus C, Denmark
| | - Luc Beaulieu
- CHU de Quebec-Université Laval, Quebec, Canada.,Université Laval, Quebec, Canada
| | - Sam Beddar
- The University of Texas MD Anderson Cancer Center, Houston, TX, USA
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Jørgensen EB, Kertzscher G, Buus S, Bentzen L, Hokland SB, Rylander S, Tanderup K, Johansen JG. Accuracy of an in vivo dosimetry-based source tracking method for afterloading brachytherapy - A phantom study. Med Phys 2021; 48:2614-2623. [PMID: 33655555 DOI: 10.1002/mp.14812] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Revised: 01/07/2021] [Accepted: 02/04/2021] [Indexed: 11/07/2022] Open
Abstract
PURPOSE To report on the accuracy of an in vivo dosimetry (IVD)-based source tracking (ST) method for high dose rate (HDR) prostate brachytherapy (BT). METHODS The ST was performed on a needle-by-needle basis. A least square fit of the expected to the measured dose rate was performed using the active dwell positions in the given needle. Two fitting parameters were used to determine the position of each needle relative to the IVD detector: radial (away or toward the detector) and longitudinal (along the axis of the treatment needle). The accuracy of the ST was assessed in a phantom where the geometries of five HDR prostate BT treatments previously treated at our clinic were reproduced. For each of the five treatment geometries, one irradiation was performed with the detector placed in the middle of the implant. Furthermore, four additional irradiations were performed for one of the geometries where the detector was retracted caudally in four steps of 10-15 mm and up to 12 mm inferior of the most inferior active dwell position, which represented the prostate apex. The time resolved dose measurements were retrieved at a rate of 20 Hz using a detector based on an Al2 O3 :C radioluminescence crystal, which was placed inside a standard BT needle. Individual calibrations of the detector were performed prior to each of the nine irradiations. RESULTS Source tracking could be applied in all needles across all nine irradiations. For irradiations with the detector located in the middle region of the implant (a total of 89 needles), the mean ± standard deviation (SD, k = 1) accuracy was -0.01 mm ± 0.38 mm and 0.30 mm ± 0.38 mm in the radial and longitudinal directions, respectively. Caudal retraction of the detector did not lead to reduced accuracy as long as the detector was located superior to the most inferior active dwell positions in all needles. However, reduced accuracy was observed for detector positions inferior to the most inferior active dwell positions which corresponded to detector positions in and inferior to the prostate apex region. Detector positions in the prostate apex and 12 mm inferior to the prostate resulted in mean ± SD (k = 1) ST accuracy of 0.7 mm ± 1 mm and 2.8 mm ± 1.6 mm, respectively, in radial direction, and -1.7 mm ± 1 mm and -2.1 mm ± 1.1 mm, respectively, in longitudinal direction. The largest deviations for the configurations with those detector positions were 2.6 and 5.4 mm, respectively, in the radial direction and -3.5 and -3.8 mm, respectively, in the longitudinal direction. CONCLUSION This phantom study demonstrates that ST based on IVD during prostate BT is adequately accurate for clinical use. The ST yields submillimeter accuracy on needle positions as long as the IVD detector is positioned superior to at least one active dwell position in all needles. Locations of the detector inferior to the prostate apex result in decreased ST accuracy while detector locations in the apex region and above are advantageous for clinical applications.
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Affiliation(s)
- Erik B Jørgensen
- Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | | | - Simon Buus
- Department of Oncology, Aarhus University Hospital, Aarhus, Denmark
| | - Lise Bentzen
- Department of Oncology, Aarhus University Hospital, Aarhus, Denmark
| | | | - Susanne Rylander
- Department of Oncology, Aarhus University Hospital, Aarhus, Denmark
| | - Kari Tanderup
- Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Jacob G Johansen
- Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
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Soror T, Siebert FA, Lancellotta V, Placidi E, Fionda B, Tagliaferri L, Kovács G. Quality Assurance in Modern Gynecological HDR-Brachytherapy (Interventional Radiotherapy): Clinical Considerations and Comments. Cancers (Basel) 2021; 13:cancers13040912. [PMID: 33671552 PMCID: PMC7927078 DOI: 10.3390/cancers13040912] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Revised: 02/15/2021] [Accepted: 02/18/2021] [Indexed: 11/16/2022] Open
Abstract
Simple Summary This is a focused review discussing quality assurance during interventional brachytherapy in gynecological cancers. This topic is very large and is usually addressed from the technical and physical sides, therefore, we decided to select “hot-spots” under this large title and discuss them from the point of view of clinicians. We hope that this concise and focused review will help clinicians in improving their quality assurance protocols and draw attention to the discussed issues. Abstract The use of brachytherapy (interventional radiotherapy) in the treatment of gynecological cancers is a crucial element in both definitive and adjuvant settings. The recent developments in high-dose rate remote afterloaders, modern applicators, treatment-planning software, image guidance, and dose monitoring systems have led to improvement in the local control rates and in some cases improved the survival rates. The development of these highly advanced and complicated treatment modalities has been accompanied by challenges, which have made the existence of quality assurance protocols a must to ensure the integrity of the treatment process. Quality assurance aims at standardizing the technical and clinical procedures involved in the treatment of patients, which could eventually decrease the source of uncertainties whether technical (source/equipment related) or clinical. This commentary review sheds light (from a clinical point of view) on some potential sources of uncertainties associated with the use of modern brachytherapy in the treatment of gynecological cancers.
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Affiliation(s)
- Tamer Soror
- Radiation Oncology Department, University of Lübeck/UKSH-CL, 23538 Lübeck, Germany
- Radiation Oncology Department, National Cancer Institute (NCI), Cairo University, Cairo 11796, Egypt
- Correspondence: ; Tel.: +49-176-2369-5626
| | - Frank-André Siebert
- Clinic of Radiotherapy, University Hospital of Schleswig-Holstein, 24105 Campus Kiel, Germany;
| | - Valentina Lancellotta
- UOC Radioterapia Oncologica, Dipartimento di Diagnostica per Immagini, Radioterapia Oncologica ed Ematologia, Fondazione Policlinico Universitario A. Gemelli, IRCCS, 00168 Roma, Italy; (V.L.); (E.P.); (B.F.); (L.T.)
| | - Elisa Placidi
- UOC Radioterapia Oncologica, Dipartimento di Diagnostica per Immagini, Radioterapia Oncologica ed Ematologia, Fondazione Policlinico Universitario A. Gemelli, IRCCS, 00168 Roma, Italy; (V.L.); (E.P.); (B.F.); (L.T.)
| | - Bruno Fionda
- UOC Radioterapia Oncologica, Dipartimento di Diagnostica per Immagini, Radioterapia Oncologica ed Ematologia, Fondazione Policlinico Universitario A. Gemelli, IRCCS, 00168 Roma, Italy; (V.L.); (E.P.); (B.F.); (L.T.)
| | - Luca Tagliaferri
- UOC Radioterapia Oncologica, Dipartimento di Diagnostica per Immagini, Radioterapia Oncologica ed Ematologia, Fondazione Policlinico Universitario A. Gemelli, IRCCS, 00168 Roma, Italy; (V.L.); (E.P.); (B.F.); (L.T.)
| | - György Kovács
- Università Cattolica del Sacro Cuore, Radioterapia Oncologica, Gemelli-INTERACTS, 00168 Roma, Italy;
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40
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Verhaegen F, Fonseca GP, Johansen JG, Beaulieu L, Beddar S, Greer P, Jornet N, Kertzscher G, McCurdy B, Smith RL, Mijnheer B, Olaciregui-Ruiz I, Tanderup K. Future directions of in vivo dosimetry for external beam radiotherapy and brachytherapy. Phys Imaging Radiat Oncol 2020; 16:18-19. [PMID: 33458338 PMCID: PMC7807862 DOI: 10.1016/j.phro.2020.09.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Revised: 09/02/2020] [Accepted: 09/17/2020] [Indexed: 11/30/2022] Open
Affiliation(s)
- Frank Verhaegen
- Department of Radiation Oncology (Maastro), GROW School for Oncology, Maastricht University Medical Centre+, Maastricht, the Netherlands
| | - Gabriel P Fonseca
- Department of Radiation Oncology (Maastro), GROW School for Oncology, Maastricht University Medical Centre+, Maastricht, the Netherlands
| | - Jacob G Johansen
- Department of Oncology, Aarhus University Hospital, Palle Juul-Jensens, Boulevard 99, DK-8200 Aarhus, Denmark
| | - Luc Beaulieu
- Department of Physics, Engineering Physics & Optics and Cancer Research Center, Université Laval, Quebec City, QC, Canada
- Department of Radiation Oncology, Research Center of CHU de Québec, Université Laval, Quebec City, QC, Canada
| | - Sam Beddar
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Blvd., Unit 1420, Houston, TX 77030, United States
| | - Peter Greer
- Calvary Mater Newcastle Hospital and University of Newcastle, Newcastle, New South Wales, Australia
| | - Nuria Jornet
- Servei de Radiofísica i Radioprotecció, Hospital de la Santa Creu i Sant Pau, Barcelona, Spain
| | - Gustavo Kertzscher
- Department of Oncology, Aarhus University Hospital, Palle Juul-Jensens, Boulevard 99, DK-8200 Aarhus, Denmark
| | - Boyd McCurdy
- Medical Physics Department, CancerCare Manitoba, Winnipeg, Manitoba, Canada
| | - Ryan L Smith
- Alfred Health Radiation Oncology, Alfred Health, 55 Commercial Rd, Melbourne, VIC 3004, Australia
| | - Ben Mijnheer
- Department of Radiation Oncology, Netherlands Cancer Institute, Amsterdam, the Netherlands
| | - Igor Olaciregui-Ruiz
- Department of Radiation Oncology, Netherlands Cancer Institute, Amsterdam, the Netherlands
| | - Kari Tanderup
- Department of Oncology, Aarhus University Hospital, Palle Juul-Jensens, Boulevard 99, DK-8200 Aarhus, Denmark
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