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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] [What about the content of this article? (0)] [Affiliation(s)] [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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May L, Hardcastle N, Hernandez V, Saez J, Rosenfeld A, Poder J. Multi-institutional investigation into the robustness of intra-cranial multi-target stereotactic radiosurgery plans to delivery errors. Med Phys 2024; 51:910-921. [PMID: 38141043 DOI: 10.1002/mp.16907] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2023] [Revised: 11/13/2023] [Accepted: 12/07/2023] [Indexed: 12/24/2023] Open
Abstract
BACKGROUND The use of modulated techniques for intra-cranial stereotactic radiosurgery (SRS) results in highly modulated fields with small apertures, which may be susceptible to uncertainties in the delivery device. PURPOSE This study aimed to quantify the impact of simulated delivery errors on treatment plan dosimetry and how this is affected by treatment planning system (TPS), plan geometry, delivery technique, and plan complexity. A beam modelling error was also included as context to the dose uncertainties due to treatment delivery errors. METHODS Delivery errors were assessed for multiple-target brain SRS plans obtained through the Trans-Tasman Radiation Oncology Group (TROG) international treatment planning challenge (2018). The challenge dataset consisted of five intra-cranial targets, each with a prescription of 20 Gy. Of the final dataset of 54 plans, 51 were created using the volumetric modulated arc therapy (VMAT) technique and three used intensity modulated arc therapy (IMRT). Thirty-five plans were from the Varian Eclipse TPS, 17 from Elekta Monaco TPS, and one plan each from RayStation and Philips Pinnacle TPS. The errors introduced included: monitor unit calibration errors, multi-leaf collimator (MLC) bank offset, single MLC leaf offset, couch rotations, and collimator rotations. Dosimetric leaf gap (DLG) error was also included as a beam modelling error. Dose to targets was assessed via dose covering 98% of planning target volume (PTV) (D98%), dose covering 2% of PTV (D2%), and dose covering 99% of gross tumor volume (GTV) (D99%). Dose to organs at risk (OARs) was assessed using the volume of normal brain receiving 12 Gy (V12Gy), mean dose to normal brain, and maximum dose covering 0.03cc brainstem (D0.03cc). Plan complexity was also assessed via edge metric, modulation complexity score (MCS), mean MLC gap, mean MLC speed, and plan modulation (PM). RESULTS PTV D98% showed high robustness on average to most errors with the exception of a bank shift of 1.0 mm and large rotational errors ≥1.0° for either the couch or collimator. However, in some cases, errors close to or within generally accepted machine tolerances resulted in clinically relevant impacts. The greatest impact upon normal brain V12Gy, mean dose to normal brain, and D0.03cc brainstem was found for DLG error in alignment with other recent studies. All delivery errors had on average a minimal impact across these parameters. Comparing plans from the Monaco TPS and the Eclipse TPS, showed a lesser increase to V12Gy, mean dose to normal brain, and D0.03cc brainstem for Monaco plans (p < 0.01) when DLG error was simulated. Monaco plans also correlated to lower plan complexity. Using Spearman's correlation coefficient (r) a strong negative correlation (r ≤ -0.8) was found between the mean MLC gap and dose to OARs for DLG errors. CONCLUSIONS Reducing MLC complexity and using larger mean MLC gaps is recommended to improve plan robustness and reduce sensitivity to delivery and modelling errors. For cases in which the calculated dose distribution or dose indices are close to the clinically acceptable limits, this is especially important.
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Affiliation(s)
- Lauren May
- Centre for Medical and Radiation Physics, University of Wollongong, North Wollongong, NSW, Australia
| | - Nicholas Hardcastle
- Centre for Medical and Radiation Physics, University of Wollongong, North Wollongong, NSW, Australia
- Physical Sciences, Peter MacCallum Cancer Centre, Melbourne, VIC, Australia
| | - Victor Hernandez
- Department of Medical Physics, Hospital Universitari Sant Joan de Reus, IISPV, Tarragona, Spain
| | - Jordi Saez
- Department of Radiation Oncology, Hospital Clínic de Barcelona, Barcelona, Spain
| | - Anatoly Rosenfeld
- Centre for Medical and Radiation Physics, University of Wollongong, North Wollongong, NSW, Australia
| | - Joel Poder
- Centre for Medical and Radiation Physics, University of Wollongong, North Wollongong, NSW, Australia
- St George Cancer Care Centre, St George Hospital, Kogarah, NSW, Australia
- School of Physics, University of Sydney, Camperdown, NSW, 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) 2024; 24:692. [PMID: 38276383 PMCID: PMC10818778 DOI: 10.3390/s24020692] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [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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Poder J, Radvan S, Howie A, Kasraei F, Parker A, Bucci J, Haworth A. Viability of focal dose escalation to prostate cancer intraprostatic lesions using HDR prostate brachytherapy. Brachytherapy 2023; 22:800-807. [PMID: 37748989 DOI: 10.1016/j.brachy.2023.09.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2023] [Revised: 08/31/2023] [Accepted: 09/01/2023] [Indexed: 09/27/2023]
Abstract
PURPOSE This study aimed to determine the viability of focal dose escalation to prostate cancer intraprostatic lesions (IPLs) from multiparametric magnetic resonance (mpMRI) and prostate-specific membrane antigen positron emission tomography (PSMA-PET) images using high-dose-rate (HDR) prostate brachytherapy (pBT). METHODS AND MATERIALS Retrospective data from 20 patients treated with HDR pBT was utilized. The interobserver contouring variability of 5 observers was quantified using the dice similarity coefficient (DSC) and mean distance to agreement (MDA). Uncertainty in propagating IPL contours to trans-rectal ultrasound (TRUS) was quantified using a tissue equivalent prostate phantom. Feasibility of incorporating IPLs into HDR pBT planning was tested on retrospective patient data. RESULTS The average observer DSC was 0.65 (PSMA-PET) and 0.52 (mpMRI). The uncertainty in propagating IPL contours was 0.6 mm (PSMA-PET), and 0.4 mm (mpMRI). Uncertainties could be accounted for by expanding IPL contours by 2 mm to create IPL PTVs. The mean D98% achieved using HDR pBT was 166% and 135% for the IPL and IPL PTV contours, respectively. CONCLUSIONS Focal dose escalation to IPLs identified on either PSMA-PET or mpMRI is viable using TRUS-based HDR pBT. Utilizing HDR pBT allows dose escalation of up to 166% of the prescribed dose to the prostate.
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Affiliation(s)
- Joel Poder
- Department of Radiation Oncology, St George Hospital Cancer Care Centre, Kogarah, NSW, Australia; Centre for Medical Radiation Physics, University of Wollongong, Wollongong, NSW, Australia; School of Physics, University of Sydney, Camperdown, NSW, Australia.
| | - Samantha Radvan
- School of Physics, University of Sydney, Camperdown, NSW, Australia
| | - Andrew Howie
- Department of Radiation Oncology, St George Hospital Cancer Care Centre, Kogarah, NSW, Australia
| | - Farshad Kasraei
- Department of Radiation Oncology, St George Hospital Cancer Care Centre, Kogarah, NSW, Australia
| | - Annaleise Parker
- Department of Radiation Oncology, St George Hospital Cancer Care Centre, Kogarah, NSW, Australia
| | - Joseph Bucci
- Department of Radiation Oncology, St George Hospital Cancer Care Centre, Kogarah, NSW, Australia
| | - Annette Haworth
- School of Physics, University of Sydney, Camperdown, NSW, Australia
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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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: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [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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Pudsey LMM, Biasi G, Ralston A, Rosenfeld A, Poder J. Detection of rotational errors in single-isocenter multiple-target radiosurgery: Is a routine off-axis Winston-Lutz test necessary? J Appl Clin Med Phys 2022; 23:e13665. [PMID: 35713881 PMCID: PMC9512335 DOI: 10.1002/acm2.13665] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Revised: 03/30/2022] [Accepted: 05/09/2022] [Indexed: 12/02/2022] Open
Abstract
Purpose Recently the use of linear accelerator (linac)‐based stereotactic radiosurgery (SRS) has increased, including single‐isocenter multiple‐target SRS. The workload of medical physicists has grown as a result and so has the necessity of maximizing the efficiency of quality assurance (QA). This study aimed to determine if measurement‐based patient‐specific QA with a high‐spatial‐resolution dosimeter is sensitive to rotational errors, potentially reducing the need for routine off‐axis Winston–Lutz (WL) testing. Methods The impact of rotational errors along gantry, couch, and collimator axes on dose coverage of the gross tumor volume (GTV) and planning target volume (PTV) was determined with a 1‐mm GTV/PTV expansion margin. Two techniques, the off‐axis WL test using the StereoPHAN MultiMet‐WL Cube (Sun Nuclear Corporation, Melbourne, Florida, USA) and patient‐specific QA using the SRS MapCHECK (Sun Nuclear Corporation, Melbourne, Florida, USA), were assessed on their ability to detect introduced errors before target coverage was compromised. These findings were also considered in the context of routine machine QA of rotational axis calibrations. Results Rotational errors significantly impacted PTV dose coverage, especially in the couch angle. GTV dose coverage remained unaffected except for with large couch angle errors (≥1.5°). The off‐axis WL test was shown to be sensitive to rotational errors with results consistently exceeding tolerance levels when or before coverage fell below departmentally accepted limits. Although patient‐specific QA using the SRS MapCHECK was previously validated for SRS, this study showed inconsistency in detection of rotational errors. Conclusions It is recommended that off‐axis WL testing be conducted regularly to supplement routine monthly machine QA, as it is sensitive to errors that patient‐specific QA may not detect. This frequency should be determined by individual departments, with consideration of GTV–PTV margins used, limitations on target off‐axis distances, and routine mechanical QA results for particular linacs.
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Affiliation(s)
- Lauren M M Pudsey
- Centre for Medical Radiation Physics, School of Physics, University of Wollongong, Wollongong, New South Wales, Australia
| | - Giordano Biasi
- Centre for Medical Radiation Physics, School of Physics, University of Wollongong, Wollongong, New South Wales, Australia.,Peter MacCallum Cancer Centre, Melbourne, Victoria, Australia
| | - Anna Ralston
- St George Hospital Cancer Care Centre, Kogarah, New South Wales, Australia
| | - Anatoly Rosenfeld
- Centre for Medical Radiation Physics, School of Physics, University of Wollongong, Wollongong, New South Wales, Australia
| | - Joel Poder
- Centre for Medical Radiation Physics, School of Physics, University of Wollongong, Wollongong, New South Wales, Australia.,St George Hospital Cancer Care Centre, Kogarah, New South Wales, Australia
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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: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [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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Pudsey L, Haworth A, White P, Moutrie Z, Jonker B, Foote M, Poder J. Current status of intra-cranial stereotactic radiotherapy and stereotactic radiosurgery in Australia and New Zealand: key considerations from a workshop and surveys. Phys Eng Sci Med 2022; 45:251-259. [PMID: 35113342 PMCID: PMC8901507 DOI: 10.1007/s13246-022-01108-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Accepted: 01/20/2022] [Indexed: 12/22/2022]
Abstract
Recently, there has been increased interest worldwide in the use of conventional linear accelerator (linac)-based systems for delivery of stereotactic radiosurgery/radiotherapy (SRS/SRT) contrasting with historical delivery in specialised clinics with dedicated equipment. In order to gain an understanding and define the current status of SRS/SRT delivery in Australia and New Zealand (ANZ) we conducted surveys and provided a single-day workshop. Prior to the workshop ANZ medical physicists were invited to complete two surveys: a departmental survey regarding SRS/SRT practises and equipment; and an individual survey regarding opinions on current and future SRS/SRT practices. At the workshop conclusion, attendees completed a second opinion-based survey. Workshop discussion and survey data were utilised to identify areas of consensus, and areas where a community consensus was unclear. The workshop was held on the 8th Sept 2020 virtually due to pandemic-related travel restrictions and was attended by 238 radiation oncology medical physicists from 39 departments. The departmental survey received 32 responses; a further 89 and 142 responses were received to the pre-workshop and post-workshop surveys respectively. Workshop discussion indicated a consensus that for a department to offer an SRS/SRT service, a minimum case load should be considered depending on availability of training, peer-review, resources and equipment. It was suggested this service may be limited to brain metastases only, with less common indications reserved for departments with comprehensive SRS/SRT programs. Whilst most centres showed consensus with treatment delivery techniques and image guidance, opinions varied on the minimum target diameter and treatment margin that should be applied.
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Affiliation(s)
- Lauren Pudsey
- Centre for Medical Radiation Physics, University of Wollongong, Wollongong, NSW, Australia
| | - Annette Haworth
- Institute of Medical Physics, School of Physics, University of Sydney, Sydney, Australia
| | - Paul White
- Nelune Comprehensive Cancer Centre, Prince of Wales Hospital, Sydney, NSW, Australia
| | - Zoe Moutrie
- Department of Radiation Oncology, Mater Hospital, GenesisCare, Crows Nest, Sydney, NSW, Australia
| | - Benjamin Jonker
- RPA Institute of Academic Surgery, University of Sydney, Sydney, Australia
| | - Matthew Foote
- University of Queensland, Princess Alexandra Hospital, ICON Cancer Care Queensland, Southport, Australia
| | - Joel Poder
- Centre for Medical Radiation Physics, University of Wollongong, Wollongong, NSW, Australia. .,St George Hospital Cancer Care Centre, Kogarah, NSW, Australia.
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Pudsey LMM, Cutajar D, Wallace A, Saba A, Schmidt L, Bece A, Clark C, Yamada Y, Biasi G, Rosenfeld A, Poder J. The use of collimator angle optimization and jaw tracking for VMAT-based single-isocenter multiple-target stereotactic radiosurgery for up to six targets in the Varian Eclipse treatment planning system. J Appl Clin Med Phys 2021; 22:171-182. [PMID: 34288376 PMCID: PMC8425912 DOI: 10.1002/acm2.13360] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Revised: 06/30/2021] [Accepted: 07/02/2021] [Indexed: 11/06/2022] Open
Abstract
PURPOSE Island blocking occurs in single-isocenter multiple-target (SIMT) stereotactic radiotherapy (SRS) whenever targets share multi-leaf collimator (MLC) leaf pairs. This study investigated the effect on plan quality and delivery, of reducing island blocking through collimator angle optimization (CAO). In addition, the effect of jaw tracking in this context was also investigated. METHODS For CAO, an algorithm was created that selects the collimator angle resulting in the lowest level of island blocking, for each beam in any given plan. Then, four volume-modulated arc therapy (VMAT) SIMT SRS plans each were generated for 10 retrospective patients: two CAO plans, with and without jaw tracking, and two plans with manually selected collimator angles, with and without jaw tracking. Plans were then assessed and compared using typical quality assurance procedures. RESULTS There were no substantial differences between plans with and without CAO. Jaw tracking produced statistically significant reduction in low-dose level parameters; healthy brain V10% and mean dose were reduced by 9.66% and 15.58%, respectively. However, quantitative values (108 cc for V10% and 0.35 Gy for mean dose) were relatively small in relation to clinical relevance. Though there were no statistically significant changes in plan deliverability, there was a notable trend of plans with jaw tracking having lower gamma analysis pass rates. CONCLUSION These findings suggest that CAO has limited benefit in VMAT SIMT SRS of 2-6 targets when using a low-dose penalty to the healthy brain during plan optimization in Eclipse. As clinical benefits of jaw tracking were found to be minimal and plan deliverability was potentially reduced, a cautious approach would be to exclude jaw tracking in SIMT SRS plans.
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Affiliation(s)
- Lauren M M Pudsey
- 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 Hospital Cancer Care Centre, Kogarah, NSW, Australia
| | - Alex Wallace
- St George Hospital Cancer Care Centre, Kogarah, NSW, Australia
| | - Anastasia Saba
- St George Hospital Cancer Care Centre, Kogarah, NSW, Australia
| | - Laurel Schmidt
- Centre for Medical Radiation Physics, University of Wollongong, Wollongong, NSW, Australia
| | - Andrej Bece
- St George Hospital Cancer Care Centre, Kogarah, NSW, Australia
| | - Catherine Clark
- Centre for Medical Radiation Physics, University of Wollongong, Wollongong, NSW, Australia
| | - Yoshiya Yamada
- Department of Radiation Oncology, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Giordano Biasi
- Centre for Medical Radiation Physics, University of Wollongong, Wollongong, NSW, Australia
| | - Anatoly Rosenfeld
- Centre for Medical Radiation Physics, University of Wollongong, Wollongong, NSW, Australia
| | - Joel Poder
- Centre for Medical Radiation Physics, University of Wollongong, Wollongong, NSW, Australia.,St George Hospital Cancer Care Centre, Kogarah, NSW, Australia
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Poder J, Cutajar D, Howie A, Petasecca M, Lerch M, Bucci J, Rosenfeld A. SP-0056 In vivo HDR brachytherapy source tracking with point dosimeters: current status and future directions. Radiother Oncol 2021. [DOI: 10.1016/s0167-8140(21)06483-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Vozzo M, Poder J, Yuen J, Bucci J, Haworth A. Use of deformable image registration techniques to estimate dose to organs at risk following prostate external beam radiation therapy and high-dose-rate brachytherapy. J Contemp Brachytherapy 2021; 13:72-79. [PMID: 34025739 PMCID: PMC8117714 DOI: 10.5114/jcb.2021.103589] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2020] [Accepted: 12/24/2020] [Indexed: 01/04/2023] Open
Abstract
PURPOSE The purpose of this investigation was to examine differences in estimates of accumulated rectal dose when using deformable image registration (DIR) compared with rigid image registration (RIR) methods, and parameter addition methods for combined transrectal ultrasound (TRUS)-based high-dose-rate brachytherapy (HDR-BT) and external beam radiation therapy (EBRT) treatments of prostate cancer. MATERIAL AND METHODS In this retrospective study, data from 10 patients who had previously received HDR-BT in one 15 Gy fraction, followed by 46 Gy EBRT in twenty-three fractions were used. To estimate total combined dose to the rectum, dose accumulation using both DIR and RIR methods were compared with parameter addition methods, which assume the same region of rectal anatomy receives the maximum dose from both treatment modalities. For both rigid and deformable image registration techniques, the quality of image registration was evaluated through metrics, including mean distance to agreement and dice similarity coefficient of prostate contours. Total D1cc and D2cc for the rectum was calculated and compared using each method. RESULTS The parameter addition methods predicted the highest accumulated dose to the rectum. On average, the predicted D2cc dose was higher than that calculated by the DIR method by 6.59 Gy EQD2 (range, -3.03 to 13.68 Gy EQD2) for partial parameter addition (PPA), and 4.88 Gy EQD2 (range, -3.41 to 11.97 Gy EQD2) for the full parameter addition (FPA) methods. Similarly, RIR predicted higher average doses compared with DIR, with a difference of 3.46 Gy EQD2 (range, -5.50 to 7.90 Gy EQD2). The results showed a significant difference between DIR and parameter addition methods for dose estimation. CONCLUSIONS This retrospective study demonstrates significant differences in accumulated rectal dose prediction using different image registration methods. Each method has limitations in its application, and when used with real-time HDR-BT dose planning, awareness of these limitations is essential.
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Affiliation(s)
- Marie Vozzo
- School of Physics, University of Sydney, Sydney, Australia
| | - Joel Poder
- St George Cancer Care Centre, Kogarah, Australia
- Centre for Medical Radiation Physics, University of Wollongong, Wollongong, Australia
| | - Johnson Yuen
- St George Cancer Care Centre, Kogarah, Australia
- South Western Clinical School, University of New South Wales, Sydney, Australia
- Ingham Institute for Applied Medical Research, Sydney, Australia
| | - Joseph Bucci
- St George Cancer Care Centre, Kogarah, Australia
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Howie A, Poder J, Brown R, Schreiber K, Bece A, Graham P, Chin YS. Comparison of TG43 and Hounsfield Unit-based TG186 brachytherapy dose metrics in Oncentra Brachy for 100 patients receiving interstitial partial breast irradiation. Brachytherapy 2021; 20:655-663. [PMID: 33358142 DOI: 10.1016/j.brachy.2020.11.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Revised: 11/23/2020] [Accepted: 11/24/2020] [Indexed: 10/22/2022]
Abstract
PURPOSE The aim of the study was to conduct a retrospective analysis of 100 patients who received interstitial accelerated partial breast irradiation at a single institution, comparing the standard American Association of Physicists in Medicine Task Group (TG) 43 dose calculation algorithm to the model-based dose calculation algorithms (MBDCAs) available in the Oncentra Brachy treatment planning system. METHODS AND MATERIALS Dose-volume histogram parameters were compared between the different dose calculation algorithms for the planning target volume and organs at risk. and a statistical analysis was performed. The resulting changes in isodose distribution were assessed, with the worst-case data presented. RESULTS The TG43 algorithm calculated higher doses to all structures compared with the MBDCAs. The largest discrepancy was observed for the skin, with maximum doses on average 2.0% lower with the MBDCA. The newly released Hounsfield Unit-based algorithm further decreased the skin dose compared with TG43 by <0.5%. CONCLUSIONS This study demonstrates that the differences between TG43 and MBDCA as implemented in Oncentra Brachy for accelerated partial breast irradiation are clinically insignificant in the treatment area and nearby organs at risk. Justification for investing in MBDCAs for this treatment site is limited when considering the additional calculation time, introduced uncertainties, and cost.
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Affiliation(s)
- Andrew Howie
- St George Cancer Care Centre, Kogarah, New South Wales, Australia.
| | - Joel Poder
- St George Cancer Care Centre, Kogarah, New South Wales, Australia; Centre for Medical Radiation Physics, University of Wollongong, Wollongong, New South Wales, Australia
| | - Ryan Brown
- St George Cancer Care Centre, Kogarah, New South Wales, Australia
| | | | - Andrej Bece
- St George Cancer Care Centre, Kogarah, New South Wales, Australia
| | - Peter Graham
- St George Cancer Care Centre, Kogarah, New South Wales, Australia; School of Medicine, University of New South Wales, Randwick, New South Wales, Australia
| | - Yaw Sinn Chin
- St George Cancer Care Centre, Kogarah, New South Wales, Australia; School of Medicine, University of New South Wales, Randwick, New South Wales, Australia
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Barber J, Yuen J, Jameson M, Schmidt L, Sykes J, Gray A, Hardcastle N, Choong C, Poder J, Walker A, Yeo A, Archibald‐Heeren B, Harrison K, Haworth A, Thwaites D. Deforming to Best Practice: Key considerations for deformable image registration in radiotherapy. J Med Radiat Sci 2020; 67:318-332. [PMID: 32741090 PMCID: PMC7754021 DOI: 10.1002/jmrs.417] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2020] [Revised: 05/15/2020] [Accepted: 06/12/2020] [Indexed: 12/11/2022] Open
Abstract
Image registration is a process that underlies many new techniques in radiation oncology - from multimodal imaging and contour propagation in treatment planning to dose accumulation throughout treatment. Deformable image registration (DIR) is a subset of image registration subject to high levels of complexity in process and validation. A need for local guidance to assist in high-quality utilisation and best practice was identified within the Australian community, leading to collaborative activity and workshops. This report communicates the current limitations and best practice advice from early adopters to help guide those implementing DIR in the clinic at this early stage. They are based on the state of image registration applications in radiotherapy in Australia and New Zealand (ANZ), and consensus discussions made at the 'Deforming to Best Practice' workshops in 2018. The current status of clinical application use cases is presented, including multimodal imaging, automatic segmentation, adaptive radiotherapy, retreatment, dose accumulation and response assessment, along with uptake, accuracy and limitations. Key areas of concern and preliminary suggestions for commissioning, quality assurance, education and training, and the use of automation are also reported. Many questions remain, and the radiotherapy community will benefit from continued research in this area. However, DIR is available to clinics and this report is intended to aid departments using or about to use DIR tools now.
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Affiliation(s)
- Jeffrey Barber
- Sydney West Radiation Oncology NetworkBlacktown and WestmeadNSWAustralia
- Institute of Medical PhysicsUniversity of SydneySydneyNSWAustralia
| | - Johnson Yuen
- St George Cancer Care CentreSydneyNSWAustralia
- Ingham Institute for Applied Medical ResearchSydneyNSWAustralia
- South Western Clinical SchoolThe University of New South WalesSydneyNSWAustralia
| | - Michael Jameson
- Liverpool and Macarthur Cancer Therapy CentresSydneyNSWAustralia
- Ingham Institute for Applied Medical ResearchSydneyNSWAustralia
- South Western Clinical SchoolThe University of New South WalesSydneyNSWAustralia
| | | | - Jonathan Sykes
- Sydney West Radiation Oncology NetworkBlacktown and WestmeadNSWAustralia
- Institute of Medical PhysicsUniversity of SydneySydneyNSWAustralia
| | - Alison Gray
- Liverpool and Macarthur Cancer Therapy CentresSydneyNSWAustralia
- Ingham Institute for Applied Medical ResearchSydneyNSWAustralia
- South Western Clinical SchoolThe University of New South WalesSydneyNSWAustralia
| | - Nicholas Hardcastle
- Peter MacCallum Cancer CentreVictoriaAustralia
- Physical SciencesPeter MacCallum Cancer CentreVICAustralia
| | - Callie Choong
- Liverpool and Macarthur Cancer Therapy CentresSydneyNSWAustralia
| | - Joel Poder
- St George Cancer Care CentreSydneyNSWAustralia
- Physical SciencesPeter MacCallum Cancer CentreVICAustralia
| | - Amy Walker
- Liverpool and Macarthur Cancer Therapy CentresSydneyNSWAustralia
- Ingham Institute for Applied Medical ResearchSydneyNSWAustralia
- South Western Clinical SchoolThe University of New South WalesSydneyNSWAustralia
| | - Adam Yeo
- Peter MacCallum Cancer CentreVictoriaAustralia
- RMIT UniversityMelbourneVICAustralia
| | | | | | - Annette Haworth
- Institute of Medical PhysicsUniversity of SydneySydneyNSWAustralia
| | - David Thwaites
- Sydney West Radiation Oncology NetworkBlacktown and WestmeadNSWAustralia
- Institute of Medical PhysicsUniversity of SydneySydneyNSWAustralia
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Ralston A, Graham P, Poder J, Yuen J. The RABBIT risk-based approach to clinical implementation of new technology: SRS as a case study. Tech Innov Patient Support Radiat Oncol 2020; 14:51-60. [PMID: 32566770 PMCID: PMC7296429 DOI: 10.1016/j.tipsro.2020.04.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2019] [Revised: 04/03/2020] [Accepted: 04/28/2020] [Indexed: 12/03/2022] Open
Abstract
Radiation oncology technology continues to evolve rapidly, resulting in advanced versions frequently being brought to market. Before a new product is used standard tests are carried out to reduce the risks associated with failure of the equipment to comply with well-established technical specifications. It is much harder to identify and reduce the risks associated with how the new technology is used clinically, such as those related to poor communication and high workload. To ensure that new technology and techniques are used safely and appropriately the implementation project should be managed by a multidisciplinary team (MDT) made up of representatives from all the relevant professions. The MDT’s role is to agree on the project scope, identify and rank all risks and benefits, and direct resources towards mitigating the highest risks. Before clinical release there should be consensus from the MDT that the benefits of the new technology outweigh the residual risks. The introduction of initiatives to optimise current practice may involve major changes which can be met with barriers such as limited support from management, insufficient time for MDT meetings, and staff fearful of being shown to have poor practices. To help overcome these challenges our team at St George Hospital Cancer Care Centre has developed a Risk and Benefit Balance Impact Template (RABBIT), which guides an MDT through the rapid implementation and safe use of new technology and techniques with an easy to follow Microsoft Word document. The implementation of stereotactic radiosurgery is used as a case study to illustrate the RABBIT methodology. The RABBIT is a user-friendly method for a busy radiotherapy clinic to transition to a risk-based MDT approach for the implementation of new technologies and techniques. When staff from all disciplines feel empowered to raise concerns about risks the workplace become inherently safer for patients and staff alike.
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Affiliation(s)
- Anna Ralston
- Cancer Care Centre, St George Hospital, Kogarah, NSW, Australia.,Centre for Medical Radiation Physics, University of Wollongong, Australia
| | - Peter Graham
- Cancer Care Centre, St George Hospital, Kogarah, NSW, Australia.,St George and Sutherland Clinical School, Faculty of Medicine, University of New South Wales, Australia
| | - Joel Poder
- Cancer Care Centre, St George Hospital, Kogarah, NSW, Australia.,Centre for Medical Radiation Physics, University of Wollongong, Australia
| | - Johnson Yuen
- Cancer Care Centre, St George Hospital, Kogarah, NSW, Australia.,South Western Clinical School, University of New South Wales, Australia.,Ingham Institute for Applied Medical Research, Sydney, Australia
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Poder J, Smith R, Haworth A. Low-dose-rate iodine-125 seed air kerma strength measurement intercomparison. Brachytherapy 2019; 19:119-125. [PMID: 31757573 DOI: 10.1016/j.brachy.2019.10.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2019] [Revised: 09/11/2019] [Accepted: 10/11/2019] [Indexed: 11/26/2022]
Abstract
PURPOSE The purpose of this study was to investigate the rate of compliance of air kerma strength (AKS) measurements of iodine-125 (I-125) seeds with international recommendations by departments in Australia and determine the potential impact of noncompliance. METHODS AND MATERIALS To achieve this aim, we present an intercomparison of AKS measurements for a single I-125 seed performed by 11 radiotherapy departments in Australia. Measurements were performed at two sites, with each participating department traveling to one of the two host sites and measuring the AKS using their own equipment and local protocols. Each of the AKS measurements was compared with each other and the manufacturer-certified AKS. RESULTS Nine of the 11 participating departments measured AKS fell within ±3% of the manufacturer's calibration certificate value, whereas all participating departments measured AKS within ±5% of the manufacturer's calibration certificate value. The total spread of the measured AKS among the 11 departments was 7.7%. Only two of the 11 participating departments complied with international recommendations and had their well chamber calibrated within the last 2 years. In addition, 2 of the 11 departments used a well chamber calibrated that was calibrated with a different seed model used during the intercomparison, whereas 4 of the 11 departments calibrated their well chamber "in-house" using a factory-calibrated seed provided by the seed manufacturer. CONCLUSIONS A significant variation in the methods used and frequency of calibration of well chambers were observed among the participating departments. The results of this study support the international recommendations on frequency and methodology of well chamber calibration. Failure to follow these recommendations significantly increases the uncertainty in AKS measurement of I-125 seeds.
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Affiliation(s)
- Joel Poder
- St George Hospital Cancer Care Centre, Kogarah, New South Wales, Australia; Centre for Medical Radiation Physics, University of Wollongong, Wollongong, New South Wales, Australia.
| | - Ryan Smith
- Alfred Health Radiation Oncology, The Alfred Hospital, Melbourne, Victoria, Australia
| | - Annette Haworth
- School of Physics, University of Sydney, Camperdown, New South Wales, Australia
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Poder J, Carrara M, Howie A, Cutajar D, Bucci J, Rosenfeld A. Derivation of in vivo source tracking error thresholds for TRUS-based HDR prostate brachytherapy through simulation of source positioning errors. Brachytherapy 2019; 18:711-719. [DOI: 10.1016/j.brachy.2019.05.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2019] [Revised: 04/23/2019] [Accepted: 05/03/2019] [Indexed: 10/26/2022]
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Poder J, Cutajar D, Guatelli S, Petasecca M, Howie A, Bucci J, Carrara M, Rosenfeld A. A Monte Carlo study on the feasibility of real-time in vivo source tracking during ultrasound based HDR prostate brachytherapy treatments. Phys Med 2019; 59:30-36. [DOI: 10.1016/j.ejmp.2019.02.012] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/10/2018] [Revised: 12/14/2018] [Accepted: 02/14/2019] [Indexed: 10/27/2022] Open
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Romanyukha A, Carrara M, Mazzeo D, Tenconi C, Al-Salmani T, Poder J, Cutajar D, Fuduli I, Petasecca M, Bucci J, Cerrotta A, Pappalardi B, Piccolo F, Pignoli E, Rosenfeld A. An innovative gynecological HDR brachytherapy applicator system for treatment delivery and real-time verification. Phys Med 2019; 59:151-157. [DOI: 10.1016/j.ejmp.2019.03.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/03/2018] [Revised: 02/27/2019] [Accepted: 03/01/2019] [Indexed: 10/27/2022] Open
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Poder J, Brown R, Porter H, Gupta R, Ralston A. Development of a dedicated phantom for multi-target single-isocentre stereotactic radiosurgery end to end testing. J Appl Clin Med Phys 2018; 19:99-108. [PMID: 30221462 PMCID: PMC6236824 DOI: 10.1002/acm2.12452] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2018] [Revised: 08/12/2018] [Accepted: 08/16/2018] [Indexed: 11/11/2022] Open
Abstract
PURPOSE The aim of this project was to design and manufacture a cost-effective end-to-end (E2E) phantom for quantifying the geometric and dosimetric accuracy of a linear accelerator based, multi-target single-isocenter (MTSI) frameless stereotactic radiosurgery (SRS) technique. METHOD A perspex Multi-Plug device from a Sun Nuclear ArcCheck phantom (Sun Nuclear, Melbourne, FL) was enhanced to make it more applicable for MTSI SRS E2E testing. The following steps in the SRS chain were then analysed using the phantom: magnetic resonance imaging (MRI) distortion, planning computed tomography (CT) scan and MRI image registration accuracy, phantom setup accuracy using CBCT, dosimetric accuracy using ion chamber, planar film dose measurements and coincidence of linear accelerator mega-voltage (MV), and kilo-voltage (kV) isocenters using Winston-Lutz testing (WLT). RESULTS The dedicated E2E phantom was able to successfully quantify the geometric and dosimetric accuracy of the MTSI SRS technique. MRI distortions were less than 0.5 mm, or half a voxel size. The average MRI-CT registration accuracy was 0.15 mm (±0.31 mm), 0.20 mm (±0.16 mm), and 0.39 mm (±0.11 mm) in the superior/inferior, left/right and, anterior/posterior directions, respectively. The phantom setup accuracy using CBCT was better than 0.2 mm and 0.1°. Point dose measurements were within 5% of the treatment planning system predicted dose. The comparison of planar film doses to the planning system dose distributions, performed using gamma analysis, resulted in pass rates greater than 97% for 3%/1 mm gamma criteria. Finally, off-axis WLT showed MV/kV coincidence to be within 1 mm for off-axis distances up to 60 mm. CONCLUSION A novel, versatile and cost-effective phantom for comprehensive E2E testing of MTSI SRS treatments was developed, incorporating multiple detector types and fiducial markers. The phantom is capable of quantifying the accuracy of each step in the MTSI SRS planning and treatment process.
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Affiliation(s)
- Joel Poder
- St George Hospital Cancer Care CentreKogarahNSWAustralia
| | - Ryan Brown
- St George Hospital Cancer Care CentreKogarahNSWAustralia
| | - Harry Porter
- St George Hospital Cancer Care CentreKogarahNSWAustralia
| | - Rashmi Gupta
- St George Hospital Cancer Care CentreKogarahNSWAustralia
| | - Anna Ralston
- St George Hospital Cancer Care CentreKogarahNSWAustralia
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Poder J, Cutajar D, Guatelli S, Petasecca M, Howie A, Bucci J, Rosenfeld A. HDR brachytherapy in vivo source position verification using a 2D diode array: A Monte Carlo study. J Appl Clin Med Phys 2018; 19:163-172. [PMID: 29855128 PMCID: PMC6036394 DOI: 10.1002/acm2.12360] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2018] [Revised: 03/21/2018] [Accepted: 04/18/2018] [Indexed: 11/23/2022] Open
Abstract
PURPOSE This study aims to assess the accuracy of source position verification during high-dose rate (HDR) prostate brachytherapy using a novel, in-house developed two-dimensional (2D) diode array (the Magic Plate), embedded exactly below the patient within a carbon fiber couch. The effect of tissue inhomogeneities on source localization accuracy is examined. METHOD Monte Carlo (MC) simulations of 12 source positions from a HDR prostate brachytherapy treatment were performed using the Geant4 toolkit. An Ir-192 Flexisource (Isodose Control, Veenendaal, the Netherlands) was simulated inside a voxelized patient geometry, and the dose deposited in each detector of the Magic Plate evaluated. The dose deposited in each detector was then used to localize the source position using a proprietary reconstruction algorithm. RESULTS The accuracy of source position verification using the Magic Plate embedded in the patient couch was found to be affected by the tissue inhomogeneities within the patient, with an average difference of 2.1 ± 0.8 mm (k = 1) between the Magic Plate predicted and known source positions. Recalculation of the simulations with all voxels assigned a density of water improved this verification accuracy to within 1 mm. CONCLUSION Source position verification using the Magic Plate during a HDR prostate brachytherapy treatment was examined using MC simulations. In a homogenous geometry (water), the Magic Plate was able to localize the source to within 1 mm, however, the verification accuracy was negatively affected by inhomogeneities; this can be corrected for by using density information obtained from CT, making the proposed tool attractive for use as a real-time in vivo quality assurance (QA) device in HDR brachytherapy for prostate cancer.
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Affiliation(s)
- Joel Poder
- Centre of Medical Radiation PhysicsUniversity of WollongongWollongongNSWAustralia
- St George Hospital Cancer Care CentreKogarahNSWAustralia
| | - Dean Cutajar
- Centre of Medical Radiation PhysicsUniversity of WollongongWollongongNSWAustralia
- St George Hospital Cancer Care CentreKogarahNSWAustralia
| | - Susanna Guatelli
- Centre of Medical Radiation PhysicsUniversity of WollongongWollongongNSWAustralia
| | - Marco Petasecca
- Centre of Medical Radiation PhysicsUniversity of WollongongWollongongNSWAustralia
| | - Andrew Howie
- St George Hospital Cancer Care CentreKogarahNSWAustralia
| | - Joseph Bucci
- St George Hospital Cancer Care CentreKogarahNSWAustralia
| | - Anatoly Rosenfeld
- Centre of Medical Radiation PhysicsUniversity of WollongongWollongongNSWAustralia
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Atkinson C, Yuen J, Poder J, Hau E, Chin Y. P2.14-010 The Time-Weighted Mid-Ventilation Technique: Reducing Planning Target Volumes For Patients Undergoing Lung Stereotactic Body Radiotherapy. J Thorac Oncol 2017. [DOI: 10.1016/j.jtho.2017.09.1382] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Poder J, Smith RL, Shelton N, Whitaker M, Butler D, Haworth A. High dose rate brachytherapy source measurement intercomparison. Australas Phys Eng Sci Med 2017; 40:377-383. [PMID: 28342026 DOI: 10.1007/s13246-017-0542-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2016] [Accepted: 03/16/2017] [Indexed: 11/30/2022]
Abstract
This work presents a comparison of air kerma rate (AKR) measurements performed by multiple radiotherapy centres for a single HDR 192Ir source. Two separate groups (consisting of 15 centres) performed AKR measurements at one of two host centres in Australia. Each group travelled to one of the host centres and measured the AKR of a single 192Ir source using their own equipment and local protocols. Results were compared to the 192Ir source calibration certificate provided by the manufacturer by means of a ratio of measured to certified AKR. The comparisons showed remarkably consistent results with the maximum deviation in measurement from the decay-corrected source certificate value being 1.1%. The maximum percentage difference between any two measurements was less than 2%. The comparisons demonstrated the consistency of well-chambers used for 192Ir AKR measurements in Australia, despite the lack of a local calibration service, and served as a valuable focal point for the exchange of ideas and dosimetry methods.
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Affiliation(s)
- Joel Poder
- Radiation Oncology, Chris O'Brien Lifehouse, Camperdown, NSW, Australia. .,Centre of Medical Radiation Physics, University of Wollongong, Wollongong, NSW, Australia.
| | - Ryan L Smith
- Alfred Health Radiation Oncology, The Alfred Hospital, Melbourne, VIC, Australia.,School of Applied Sciences, RMIT University, Melbourne, VIC, Australia
| | - Nikki Shelton
- Olivia Newton John Cancer and Wellness Centre, The Austin Hospital, Heidelberg, VIC, Australia
| | - May Whitaker
- Radiation Oncology, Chris O'Brien Lifehouse, Camperdown, NSW, Australia
| | - Duncan Butler
- Australian Radiation Protection and Nuclear Safety Agency, Yallambie, VIC, Australia
| | - Annette Haworth
- Physical Sciences, Peter MacCallum Cancer Centre, Melbourne, VIC, Australia.,School of Physics, University of Sydney, Camperdown, NSW, Australia
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Butson M, Chen T, Alzaidi S, Pope D, Butson E, Gorjiara T, Poder J, Cho G, Gill S, Morales J, Haque M, Whitaker M, Hill R. Extrapolated skin dose assessment with optically stimulated luminescent dosimeters. Biomed Phys Eng Express 2016. [DOI: 10.1088/2057-1976/2/4/047001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Poder J, Whitaker M. Robustness of IPSA optimized high-dose-rate prostate brachytherapy treatment plans to catheter displacements. J Contemp Brachytherapy 2016; 8:201-7. [PMID: 27504129 PMCID: PMC4965496 DOI: 10.5114/jcb.2016.60499] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2016] [Accepted: 05/03/2016] [Indexed: 11/24/2022] Open
Abstract
PURPOSE Inverse planning simulated annealing (IPSA) optimized brachytherapy treatment plans are characterized with large isolated dwell times at the first or last dwell position of each catheter. The potential of catheter shifts relative to the target and organs at risk in these plans may lead to a more significant change in delivered dose to the volumes of interest relative to plans with more uniform dwell times. MATERIAL AND METHODS This study aims to determine if the Nucletron Oncentra dwell time deviation constraint (DTDC) parameter can be optimized to improve the robustness of high-dose-rate (HDR) prostate brachytherapy plans to catheter displacements. A set of 10 clinically acceptable prostate plans were re-optimized with a DTDC parameter of 0 and 0.4. For each plan, catheter displacements of 3, 7, and 14 mm were retrospectively applied and the change in dose volume histogram (DVH) indices and conformity indices analyzed. RESULTS The robustness of clinically acceptable prostate plans to catheter displacements in the caudal direction was found to be dependent on the DTDC parameter. A DTDC value of 0 improves the robustness of planning target volume (PTV) coverage to catheter displacements, whereas a DTDC value of 0.4 improves the robustness of the plans to changes in hotspots. CONCLUSIONS The results indicate that if used in conjunction with a pre-treatment catheter displacement correction protocol and a tolerance of 3 mm, a DTDC value of 0.4 may produce clinically superior plans. However, the effect of the DTDC parameter in plan robustness was not observed to be as strong as initially suspected.
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Affiliation(s)
- Joel Poder
- Radiation Oncology, Chris O'Brien Lifehouse, Camperdown, NSW
- Centre for Medical Radiation Physics, University of Wollongong, Wollongong, NSW, Australia
| | - May Whitaker
- Radiation Oncology, Chris O'Brien Lifehouse, Camperdown, NSW
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Enari K, Bucci J, Howie A, Porter H, Yau S, Estoesta E, Flower E, Wach A, Busuttil G, Nguyen H, Martin L, Kaperlowsky J, Cutajar D, Duncan R, Poder J, Ahern V. PO-0873: The treatment of a paediatric Rhabdomyosarcoma in Australasia: a novel physics challenge. Radiother Oncol 2015. [DOI: 10.1016/s0167-8140(15)40865-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Poder J, Corde S. I-125 ROPES eye plaque dosimetry: Validation of a commercial 3D ophthalmic brachytherapy treatment planning system and independent dose calculation software with GafChromic®
EBT3 films. Med Phys 2013; 40:121709. [DOI: 10.1118/1.4828786] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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