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Iramina H, Tsuneda M, Okamoto H, Kadoya N, Mukumoto N, Toyota M, Fukunaga J, Fujita Y, Tohyama N, Onishi H, Nakamura M. Multi-institutional questionnaire-based survey on online adaptive radiotherapy performed using commercial systems in Japan in 2023. Radiol Phys Technol 2024; 17:581-595. [PMID: 39028438 DOI: 10.1007/s12194-024-00828-4] [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: 05/27/2024] [Revised: 07/12/2024] [Accepted: 07/13/2024] [Indexed: 07/20/2024]
Abstract
In this study, we aimed to conduct a survey on the current clinical practice of, staffing for, commissioning of, and staff training for online adaptive radiotherapy (oART) in the institutions that installed commercial oART systems in Japan, and to share the information with institutions that will implement oART systems in future. A web-based questionnaire, containing 107 questions, was distributed to nine institutions in Japan. Data were collected from November to December 2023. Three institutions each with the MRIdian (ViewRay, Oakwood Village, OH, USA), Unity (Elekta AB, Stockholm, Sweden), and Ethos (Varian Medical Systems, Palo Alto, CA, USA) systems completed the questionnaire. One institution (MRIdian) had not performed oART by the response deadline. Each institution had installed only one oART system. Hypofractionation, and moderate hypofractionation or conventional fractionation were employed in the MRIdian/Unity and Ethos systems, respectively. The elapsed time for the oART process was faster with the Ethos than with the other systems. All institutions added additional staff for oART. Commissioning periods differed among the oART systems owing to provision of beam data from the vendors. Chambers used during commissioning measurements differed among the institutions. Institutional training was provided by all nine institutions. To the best of our knowledge, this was the first survey about oART performed using commercial systems in Japan. We believe that this study will provide useful information to institutions that installed, are installing, or are planning to install oART systems.
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Affiliation(s)
- Hiraku Iramina
- Adaptive Radiotherapy Working Group (ART-WG), QA/QC Committee, Japan Society of Medical Physics, Tokyo, Japan
- Department of Radiation Oncology and Image-Applied Therapy, Graduate School of Medicine, Kyoto University, 54 Kawahara-Cho, Shogoin, Sakyo-Ku, Kyoto-Shi, Kyoto, 606-8507, Japan
| | - Masato Tsuneda
- Adaptive Radiotherapy Working Group (ART-WG), QA/QC Committee, Japan Society of Medical Physics, Tokyo, Japan
- Department of Radiation Oncology, MR Linac ART Division, Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuo-Ku, Chiba-Shi, Chiba, 260-8670, Japan
| | - Hiroyuki Okamoto
- Adaptive Radiotherapy Working Group (ART-WG), QA/QC Committee, Japan Society of Medical Physics, Tokyo, Japan
- Radiation Safety and Quality Assurance Division, National Cancer Center Hospital, 5-1-1 Tsukiji, Chuo-Ku, Tokyo, 104-0045, Japan
| | - Noriyuki Kadoya
- Adaptive Radiotherapy Working Group (ART-WG), QA/QC Committee, Japan Society of Medical Physics, Tokyo, Japan
- Department of Radiation Oncology, Tohoku University Graduate School of Medicine, 1-1 Seiryo-Machi, Aoba-Ku, Sendai-Shi, Miyagi, 980-8574, Japan
| | - Nobutaka Mukumoto
- Adaptive Radiotherapy Working Group (ART-WG), QA/QC Committee, Japan Society of Medical Physics, Tokyo, Japan
- Department of Radiation Oncology, Graduate School of Medicine, Osaka Metropolitan University, 1-4-3 Asahi-Machi, Abeno-Ku, Osaka-Shi, Osaka, 545-8585, Japan
| | - Masahiko Toyota
- Adaptive Radiotherapy Working Group (ART-WG), QA/QC Committee, Japan Society of Medical Physics, Tokyo, Japan
- Division of Radiology, Department of Clinical Technology, Kagoshima University Hospital, 8-35-1 Sakuragaoka, Kagoshima-Shi, Kagoshima, 890-8520, Japan
| | - Junichi Fukunaga
- Adaptive Radiotherapy Working Group (ART-WG), QA/QC Committee, Japan Society of Medical Physics, Tokyo, Japan
- Division of Radiology, Department of Medical Technology, Kyushu University Hospital, 3-1-1 Maidashi, Higashi-Ku, Fukuoka-Shi, Fukuoka, 812-8582, Japan
| | - Yukio Fujita
- Adaptive Radiotherapy Working Group (ART-WG), QA/QC Committee, Japan Society of Medical Physics, Tokyo, Japan
- Department of Radiation Oncology, MR Linac ART Division, Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuo-Ku, Chiba-Shi, Chiba, 260-8670, Japan
- Department of Radiological Sciences, Komazawa University, 1-23-1 Komazawa, Setagaya-Ku, Tokyo, 154-8525, Japan
| | - Naoki Tohyama
- Department of Radiological Sciences, Komazawa University, 1-23-1 Komazawa, Setagaya-Ku, Tokyo, 154-8525, Japan
| | - Hiroshi Onishi
- Department of Radiology, University of Yamanashi, 1110 Shimokato, Chuo-Shi, Yamanashi, 409-3898, Japan
| | - Mitsuhiro Nakamura
- Adaptive Radiotherapy Working Group (ART-WG), QA/QC Committee, Japan Society of Medical Physics, Tokyo, Japan.
- Department of Advanced Medical Physics, Graduate School of Medicine, Kyoto University, 53 Kawahara-Cho, Shogoin, Sakyo-Ku, Kyoto-Shi, Kyoto, 606-8507, Japan.
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McGuffey AS, Pitcher GM, Erhart KJ, Hogstrom KR. Dosimetric validation of intensity-modulated bolus electron conformal therapy planning and delivery using an anthropomorphic cylindrical head phantom. J Appl Clin Med Phys 2024; 25:e14347. [PMID: 38576174 PMCID: PMC11244665 DOI: 10.1002/acm2.14347] [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: 11/21/2023] [Revised: 02/23/2024] [Accepted: 03/06/2024] [Indexed: 04/06/2024] Open
Abstract
PURPOSE This work investigated the dosimetric accuracy of the intensity-modulated bolus electron conformal therapy (IM-BECT) planning and delivery process using the decimal ElectronRT (eRT) treatment planning system. METHODS An IM-BECT treatment plan was designed using eRT for a cylindrical, anthropomorphic retromolar trigone phantom. Treatment planning involved specification of beam parameters and design of a variable thickness wax bolus and Passive Radiotherapy Intensity Modulator for Electrons (PRIME) device, which was comprised of 33 tungsten island blocks of discrete diameters from 0.158 to 0.223 cm (Intensity Reduction Factors from 0.937 to 0.875, respectively) inside a 10.1 × 6.7 cm2 copper cutout. For comparison of calculation accuracy, a BECT plan was generated by copying the IM-BECT plan and removing the intensity modulation. For both plans, a 16 MeV electron beam was used with 104.7 cm source-to-surface distance to bolus. In-phantom TLD-100 measurements (N = 47) were compared with both eRT planned dose distributions, which used the pencil beam redefinition algorithm with modifications for passive electron intensity modulation (IM-PBRA). Dose difference and distance to agreement (DTA) metrics were computed for each measurement point. RESULTS Comparison of measured dose distributions with planned dose distributions yielded dose differences (calculated minus measured) characterized by a mean and standard deviation of -0.36% ± 1.64% for the IM-BECT plan, which was similar to -0.36% ± 1.90% for the BECT plan. All dose measurements were within 5% of the planned dose distribution, with both the BECT and IM-BECT measurement sets having 46/47 (97.8%) points within 3% or within 3 mm of the respective treatment plans. CONCLUSIONS It was found that the IM-BECT treatment plan generated using eRT was sufficiently accurate for clinical use when compared to TLD measurements in a cylindrical, anthropomorphic phantom, and was similarly accurate to the BECT treatment plan in the same phantom.
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Affiliation(s)
- Andrew S. McGuffey
- Department of Physics and AstronomyLouisiana State UniversityBaton RougeLouisianaUSA
| | - Garrett M. Pitcher
- Department of Physics and AstronomyLouisiana State UniversityBaton RougeLouisianaUSA
- Mary Bird Perkins Cancer CenterBaton RougeLouisianaUSA
| | | | - Kenneth R. Hogstrom
- Department of Physics and AstronomyLouisiana State UniversityBaton RougeLouisianaUSA
- Mary Bird Perkins Cancer CenterBaton RougeLouisianaUSA
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Li S, Luo H, Tan X, Qiu T, Yang X, Feng B, Chen L, Wang Y, Jin F. The impact of plan complexity on calculation and measurement-based pre-treatment verifications for sliding-window intensity-modulated radiotherapy. Phys Imaging Radiat Oncol 2024; 31:100622. [PMID: 39220115 PMCID: PMC11364123 DOI: 10.1016/j.phro.2024.100622] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2024] [Revised: 08/01/2024] [Accepted: 08/02/2024] [Indexed: 09/04/2024] Open
Abstract
Background and purpose In sliding-window intensity-modulated radiotherapy, increased plan modulation often leads to increased plan complexities and dose uncertainties. Dose calculation and/or measurement checks are usually adopted for pre-treatment verification. This study aims to evaluate the relationship among plan complexities, calculated doses and measured doses. Materials and methods A total of 53 plan complexity metrics (PCMs) were selected, emphasizing small field characteristics and leaf speed/acceleration. Doses were retrieved from two beam-matched treatment devices. The intended dose was computed employing the Anisotropic Analytical Algorithm and validated through Monte Carlo (MC) and Collapsed Cone Convolution (CCC) algorithms. To measure the delivered dose, 3D diode arrays of various geometries, encompassing helical, cross, and oblique cross shapes, were utilized. Their interrelation was assessed via Spearman correlation analysis and principal component linear regression (PCR). Results The correlation coefficients between calculation-based (CQA) and measurement-based verification quality assurance (MQA) were below 0.53. Most PCMs showed higher correlation rpcm-QA with CQA (max: 0.84) than MQA (max: 0.65). The proportion of rpcm-QA ≥ 0.5 was the largest in the pelvis compared to head-and-neck and chest-and-abdomen, and the highest rpcm-QA occurred at 1 %/1mm. Some modulation indices for the MLC speed and acceleration were significantly correlated with CQA and MQA. PCR's determination coefficients (R2 ) indicated PCMs had higher accuracy in predicting CQA (max: 0.75) than MQA (max: 0.42). Conclusions CQA and MQA demonstrated a weak correlation. Compared to MQA, CQA exhibited a stronger correlation with PCMs. Certain PCMs related to MLC movement effectively indicated variations in both quality assurances.
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Affiliation(s)
| | | | - Xia Tan
- Departments of Radiation Oncology, Chongqing University Cancer Hospital, Chongqing, Republic of China
| | - Tao Qiu
- Departments of Radiation Oncology, Chongqing University Cancer Hospital, Chongqing, Republic of China
| | - Xin Yang
- Departments of Radiation Oncology, Chongqing University Cancer Hospital, Chongqing, Republic of China
| | - Bin Feng
- Departments of Radiation Oncology, Chongqing University Cancer Hospital, Chongqing, Republic of China
| | - Liyuan Chen
- Departments of Radiation Oncology, Chongqing University Cancer Hospital, Chongqing, Republic of China
| | - Ying Wang
- Departments of Radiation Oncology, Chongqing University Cancer Hospital, Chongqing, Republic of China
| | - Fu Jin
- Departments of Radiation Oncology, Chongqing University Cancer Hospital, Chongqing, Republic of China
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Prasath S, Babu PR. Dosimetric Validation of Treatment Planning System for Volumetric Modulated Arc Therapy Using AAPM Medical Physics Practice Guideline 5.b. Asian Pac J Cancer Prev 2024; 25:1715-1723. [PMID: 38809644 PMCID: PMC11318820 DOI: 10.31557/apjcp.2024.25.5.1715] [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: 01/05/2024] [Accepted: 05/15/2024] [Indexed: 05/31/2024] Open
Abstract
AIM To assess the precision of dose calculations for Volumetric Modulated Arc Therapy (VMAT) using megavoltage (MV) photon beams, we validated the accuracy of two algorithms: AUROS XB and Analytical Anisotropic Algorithm (AAA). This validation will encompass both flattening filter (FF) and flattening filter-free beam (FFF) modes, using AAPM Medical Physics Practice Guideline (MPPG 5b). MATERIALS AND METHODS VMAT validation tests were generated for 6 MV FF and 6 MV FFF beams using the AAA and AXB algorithms in the Eclipse V.15.1 treatment planning system (TPS). Corresponding measurements were performed on a linear accelerator using a diode detector and a radiation field analyzer. Point dose (PD) and in-vivo measurements were conducted using an A1SL ion chamber and (TLD) from Thermofisher, respectively. The Rando Phantom was employed for end-to-end (E2E) tests. RESULTS The mean difference (MD) between the TPS-calculated values and the measured values for the PDD and output factors were within 1% and 0.5%, respectively, for both 6 MV FF and 6 MV FFF. In the TG 119 sets, the MD for PD with both AAA and AXB was <0.9%. For the TG 244 sets, the minimum, maximum, and mean deviations in PD for both 6 MV FF and 6 MV FFF beams were 0.3%, 1.4% and 0.8% respectively. In the E2E test, using the Rando Phantom, the MD between the TLD dose and the TPS dose was within 0.08% for both 6 MV FF (p=1.0) and 6 MV FFF (0.018) beams. CONCLUSION The accuracy of the TPS and its algorithms (AAA and AXB) has been successfully validated. The recommended tests included in the VMAT/IMRT validation section proved invaluable for verifying the PDD, output factors, and the feasibility of complex clinical cases. E2E tests were instrumental in validating the entire workflow from CT simulation to treatment delivery.
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Affiliation(s)
- Sriram Prasath
- Division of Medical Physics, Department of Radiation Oncology, Tata Medical Center, Newtown, Rajarhat, Kolkata, West Bengal, India.
- Department of Physics, School of Advanced Sciences, Vellore Institute of Technology, Vellore, Tamil Nadu, India.
| | - Padmanabhan Ramesh Babu
- Department of Physics, School of Advanced Sciences, Vellore Institute of Technology, Vellore, Tamil Nadu, India.
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Wang D, Polignani JA. Quantitative approaches in electron skin collimation for the practical benefits. J Appl Clin Med Phys 2024; 25:e14236. [PMID: 38050939 PMCID: PMC11005976 DOI: 10.1002/acm2.14236] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2023] [Revised: 11/20/2023] [Accepted: 11/22/2023] [Indexed: 12/07/2023] Open
Affiliation(s)
- Dongxu Wang
- Department of Medical PhysicsMemorial Sloan Kettering Cancer CenterNew YorkNew YorkUSA
| | - Jonathan A. Polignani
- Department of Medical PhysicsMemorial Sloan Kettering Cancer CenterNew YorkNew YorkUSA
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Kierkels RGJ, Hernandez V, Saez J, Angerud A, Hilgers GC, Surmann K, Schuring D, Minken AWH. Multileaf collimator characterization and modeling for a 1.5 T MR-linac using static synchronous and asynchronous sweeping gaps. Phys Med Biol 2024; 69:075004. [PMID: 38412538 DOI: 10.1088/1361-6560/ad2d7d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2023] [Accepted: 02/27/2024] [Indexed: 02/29/2024]
Abstract
Objective.The Elekta unity MR-linac delivers step-and-shoot intensity modulated radiotherapy plans using a multileaf collimator (MLC) based on the Agility MLC used on conventional Elekta linacs. Currently, details of the physical Unity MLC and the computational model within its treatment planning system (TPS)Monacoare lacking in published literature. Recently, a novel approach to characterize the physical properties of MLCs was introduced using dynamic synchronous and asynchronous sweeping gap (aSG) tests. Our objective was to develop a step-and-shoot version of the dynamic aSG test to characterize the Unity MLC and the computational MLC models in theMonacoandRayStationTPSs.Approach.Dynamic aSG were discretized into a step-and-shoot aSG by investigating the number of segments/sweep and the minimal number of monitor units (MU) per segment. The step-and-shoot aSG tests were compared to the dynamic aSG tests on a conventional linac at a source-to-detector distance of 143.5 cm, mimicking the Unity configuration. the step-and-shoot aSG tests were used to characterize the Unity MLC through measurements and dose calculations in both TPSs.Main results.The step-and-shoot aSGs tests with 100 segments and 5 MU/segment gave results very similar to the dynamic aSG experiments. The effective tongue-and-groove width of the Unity gradually increased up to 1.4 cm from the leaf tip end. The MLC models inRayStationandMonacoagreed with experimental data within 2.0% and 10%, respectively. The largest discrepancies inMonacowere found for aSG tests with >10 mm leaf interdigitation, which are non-typical for clinical plans.Significance.The step-and-shoot aSG tests accurately characterize the MLC in step-and-shoot delivery mode. The MLC model inRayStation2023B accurately describes the tongue-and-groove and leaf tip effects whereasMonacooverestimates the tongue-and-groove shadowing further away from the leaf tip end.
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Affiliation(s)
| | - Victor Hernandez
- Hospital Sant Joan de Reus, Department of Medical Physics, Reus, Spain
| | - Jordi Saez
- Hospital Clínic de Barcelona, Department of Radiation Oncology, Barcelona, Spain
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ÇAĞLAR M, EŞİTMEZ D, CEBE MS. The Effect of Dose Enhancement in Tumor With Silver Nanoparticles on Surrounding Healthy Tissues: A Monte Carlo Study. Technol Cancer Res Treat 2024; 23:15330338241235771. [PMID: 38449099 PMCID: PMC10919133 DOI: 10.1177/15330338241235771] [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: 09/06/2023] [Revised: 01/18/2024] [Accepted: 02/12/2024] [Indexed: 03/08/2024] Open
Abstract
Objectives: Cancer-related death rates account for approximately one-third of all deaths, and this rate is increasing remarkably every year. In this study, we examined the dose enhancement factor (DEF) in the tumor and surrounding tissues by adding different concentrations of silver nanoparticles (AgNPs) to the brain tumor using the Monte Carlo (MC) technique. Methods: This study used MCNP6.2 simulation software. A Planning Target Volume (PTV) of 1 × 1 × 1 cm3 was placed in the center of a cubic cranial model with dimensions of 5 × 5 × 5 cm3. Five different simulations were initially generated using the simple method. These simulations included pure PTV and PTV consisting of 4 different silver concentrations (5, 10, 20, and 30 mg/g). Additionally, a model was created using the nanolattice method, considering the size, position, and distribution of the AgNPs. Irradiation was performed using a source with a 6 MV linac photon spectrum. Measurements were performed using the *f8 tally, and DEF values were calculated. Results: In the simulation study using the simple method, the DEF value of PTV increased linearly with concentration, whereas the DEF values were lower than the simulation results with the nanolattice model (1.9 vs 1.4 for 30 mg/g NP concentration). Performing the simple method, we observed no remarkable dose increase in lateral OARs surrounding PTV. While a remarkable dose decrease was observed in distal OARs, a dose increase in the proximal OAR was observed, which was consistent with that of PTV. However, according to the results obtained by performing the nanolattice method, the dose increase was observed in both the proximal OAR and the distal OAR and was similar to that of PTV. Conclusion: While enhancing the dose in the tumor by adding NPs into the tumor, it is essential to consider whether it also increases the OAR dose. In addition, simulation studies on NPs showed that the dose increase varied significantly with particle size, position, and distribution. Hence, these factors should be considered carefully.
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Affiliation(s)
- Mustafa ÇAĞLAR
- Department of Health Physics, Graduate School of Health Sciences, İstanbul Medipol University, İstanbul, Türkiye
| | - Dursun EŞİTMEZ
- Department of Health Physics, Graduate School of Health Sciences, İstanbul Medipol University, İstanbul, Türkiye
| | - Mehmet Sıddık CEBE
- Department of Health Physics, Graduate School of Health Sciences, İstanbul Medipol University, İstanbul, Türkiye
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Hussein M, Angerud A, Saez J, Bogaert E, Lemire M, Barry M, Silvestre Patallo I, Shipley D, Clark CH, Hernandez V. Improving the modelling of a multi-leaf collimator with tilted leaf sides used in radiotherapy. Phys Imaging Radiat Oncol 2024; 29:100543. [PMID: 38390588 PMCID: PMC10881418 DOI: 10.1016/j.phro.2024.100543] [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: 12/11/2023] [Revised: 01/24/2024] [Accepted: 01/25/2024] [Indexed: 02/24/2024] Open
Abstract
Background and purpose Multi-leaf collimators (MLCs) with tilted leaf sides have a complex transmission behaviour that is not easily matched by radiotherapy treatment planning systems (TPSs). We sought to develop an MLC model that can accurately match test fields and clinically relevant plans at different centres. Materials and methods Two new MLC models were developed and evaluated within a research version of a commercial TPS. Prototype I used adjusted-constant transmissions and Prototype II used variable transmissions at the tongue-and-groove and leaf-tip regions. Three different centres evaluated these prototypes for a tilted MLC and compared them with their initial MLC model using test fields and patient-specific quality-assurance measurements of clinically relevant plans. For the latter, gamma passing rates (GPR) at 2 %/2mm were recorded. Results For the prototypes the same set of MLC parameters could be used at all centres, with only a slight adjustment of the offset parameter. For centres A and C, average GPR were >95 % and within 0.5 % GPR difference between the standard, and prototype models. In center B, prototypes I and II improved the agreement in clinically relevant plans, with an increase in GPR of 2.3 % ± 0.8 % and 3.0 ± 0.8 %, respectively. Conclusions The prototype MLC models were either similar or superior to the initial MLC model, and simpler to configure because fewer trade-offs were required. Prototype I performed comparably to the more sophisticated Prototype II and its configuration can be easily standardized, which can be useful to reduce variability and improve safety in clinical practice.
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Affiliation(s)
- Mohammad Hussein
- Metrology for Medical Physics Centre, National Physical Laboratory, Teddington, UK
| | | | - Jordi Saez
- Department of Radiation Oncology, Hospital Clínic de Barcelona, Barcelona, Spain
| | - Evelien Bogaert
- Department of Radiation Oncology, Ghent University Hospital, Belgium
| | | | - Miriam Barry
- Metrology for Medical Physics Centre, National Physical Laboratory, Teddington, UK
| | | | - David Shipley
- Metrology for Medical Physics Centre, National Physical Laboratory, Teddington, UK
| | - Catharine H Clark
- Metrology for Medical Physics Centre, National Physical Laboratory, Teddington, UK
- Medical Physics, University College London Hospital, London, UK
- Medical Physics and Bioengineering, University College London, London, UK
| | - Victor Hernandez
- Department of Medical Physics, Hospital Sant Joan de Reus, IISPV, Tarragona, Spain
- Universitat Rovira i Virgili, Tarragona, Spain
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Schofield A, Newall M, Inwood D, Downes S, Corde S. Commissioning of Aktina SRS cones and dosimetric validation of the RayStation photon Monte Carlo dose calculation algorithm. Phys Eng Sci Med 2023; 46:1503-1518. [PMID: 37603132 DOI: 10.1007/s13246-023-01315-7] [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: 12/28/2022] [Accepted: 07/27/2023] [Indexed: 08/22/2023]
Abstract
Clinical implementation of SRS cones demands particular experimental care and dosimetric considerations in order to deliver precise and safe radiotherapy to patients. The purpose of this work was to present the commissioning data of recent Aktina cones combined with a 6MV flattened beam produced by an Elekta VersaHD linear accelerator. Additionally, the modelling process, and an assessment of dosimetric accuracy of the RayStation Monte Carlo dose calculation algorithm for cone based SRS was performed. There are currently no studies presenting beam data for this equipment and none that outlines the modelling parameters and validation of dose calculation using RayStation's photon Monte Carlo dose engine with cones. Beam data was measured using an SFD and a microDiamond and benchmarked against EBT3 film for cones of diameter 5-39 mm. Modelling was completed and validated within homogeneous and heterogeneous phantoms. End-to-end image-guided validation was performed using a StereoPHAN™ housing, an SRS MapCHECK and EBT3 film, and calculation time was investigated as a function of statistical uncertainty and field diameter. The TPS calculations agreed with measured data within their estimated uncertainties and clinical treatment plans could be calculated in under a minute. The data presented serves as a reference for others commissioning Aktina stereotactic cones and the modelling parameters serve similarly, while providing a starting point for those commissioning the same TPS algorithm for use with cones. It has been shown in this work that RayStation's Monte Carlo photon dose algorithm performs satisfactorily in the presence of SRS cones.
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Affiliation(s)
- Andy Schofield
- Radiation Oncology Department, Prince of Wales Hospital, Randwick, NSW, 2031, Australia
| | - Matthew Newall
- Radiation Oncology Department, Prince of Wales Hospital, Randwick, NSW, 2031, Australia
| | - Dean Inwood
- Radiation Oncology Department, Prince of Wales Hospital, Randwick, NSW, 2031, Australia
| | - Simon Downes
- Radiation Oncology Department, Prince of Wales Hospital, Randwick, NSW, 2031, Australia
| | - Stéphanie Corde
- Radiation Oncology Department, Prince of Wales Hospital, Randwick, NSW, 2031, Australia.
- Centre for Medical Radiation Physics, University of Wollongong, Wollongong, NSW, 2522, Australia.
- Illawara Health and Medical Research Institute, University of Wollongong, Wollongong, NSW, 2522, Australia.
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Krauss RF, Balik S, Cirino ET, Hadley A, Hariharan N, Holmes SM, Kielar K, Lavvafi H, McCullough K, Palefsky S, Sawyer JP, Smith K, Tracy J, Winter JD, Wingreen NE. AAPM Medical Physics Practice Guideline 8.b: Linear accelerator performance tests. J Appl Clin Med Phys 2023; 24:e14160. [PMID: 37793084 PMCID: PMC10647991 DOI: 10.1002/acm2.14160] [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: 05/11/2023] [Revised: 06/23/2023] [Accepted: 08/24/2023] [Indexed: 10/06/2023] Open
Abstract
The purpose of this guideline is to provide a list of critical performance tests to assist the Qualified Medical Physicist (QMP) in establishing and maintaining a safe and effective quality assurance (QA) program. The performance tests on a linear accelerator (linac) should be selected to fit the clinical patterns of use of the accelerator and care should be given to perform tests which are relevant to detecting errors related to the specific use of the accelerator. Current recommendations for linac QA were reviewed to determine any changes required to those tests highlighted by the original report as well as considering new components of the treatment process that have become common since its publication. Recommendations are made on the acquisition of reference data, routine establishment of machine isocenter, basing performance tests on clinical use of the linac, working with vendors to establish QA tests and performing tests after maintenance and upgrades. The recommended tests proposed in this guideline were chosen based on consensus of the guideline's committee after assessing necessary changes from the previous report. The tests are grouped together by class of test (e.g., dosimetry, mechanical, etc.) and clinical parameter tested. Implementation notes are included for each test so that the QMP can understand the overall goal of each test. This guideline will assist the QMP in developing a comprehensive QA program for linacs in the external beam radiation therapy setting. The committee sought to prioritize tests by their implication on quality and patient safety. The QMP is ultimately responsible for implementing appropriate tests. In the spirit of the report from American Association of Physicists in Medicine Task Group 100, individual institutions are encouraged to analyze the risks involved in their own clinical practice and determine which performance tests are relevant in their own radiotherapy clinics.
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Affiliation(s)
| | - Salim Balik
- University of Southern CaliforniaLos AngelesCaliforniaUSA
| | | | - Austin Hadley
- Anchorage Radiation Oncology CenterAnchorageAlaskaUSA
| | | | | | | | | | | | | | | | - Koren Smith
- UMass Chan Medical School/IROC Rhode Island QA CenterLincolnRhode IslandUSA
| | | | - Jeff D. Winter
- Department of Medical PhysicsPrincess Margaret Cancer CentreTorontoOntarioCanada
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Lobb E. Technical Report: Efficient constancy evaluation of the Eclipse treatment planning system's photon and electron dose calculation algorithms aided by the third-party ClearCheck software. Med Dosim 2023; 49:81-84. [PMID: 37748991 DOI: 10.1016/j.meddos.2023.08.009] [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: 07/13/2023] [Revised: 08/10/2023] [Accepted: 08/25/2023] [Indexed: 09/27/2023]
Abstract
Our institutional approach to performing periodic constancy checks on dose calculations for the Varian Eclipse treatment planning system is described, including details of how the Radformation ClearCheck software is leveraged for highly efficient results analysis. Photon- and electron-specific synthetic phantoms are created which allow all modality-specific fields to be spatially separated and calculated in a single plan, with field-specific structures encompassing individual irradiated volumes facilitating field-specific dose distribution evaluations. Plan comparison templates in ClearCheck allow for the near-instantaneous evaluation of 116 and 165 individual calculation metrics for photon and electron fields, respectively. The methodology is further applied to the Radformation ClearCalc finite-size pencil beam and electron algorithms for secondary algorithm validation. The total time required for constancy evaluations of 6 primary algorithms and 4 secondary algorithms is less than one hour, with much of that time used for passive dose calculation.
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Affiliation(s)
- Eric Lobb
- Department of Radiation Oncology, Ascension NE Wisconsin St. Elizabeth Hospital, Appleton, Wisconsin, USA.
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Fagerstrom JM. Dosimetric characterization of foam padding with posterior fields in palliative radiation therapy. Med Dosim 2023; 49:65-68. [PMID: 37673727 DOI: 10.1016/j.meddos.2023.08.003] [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: 03/29/2023] [Revised: 06/12/2023] [Accepted: 08/09/2023] [Indexed: 09/08/2023]
Abstract
Patients undergoing external beam radiation therapy for the palliative treatment of painful bony metastases may have difficulty maintaining a still position on a rigid uncovered couch top, both during CT simulation as well as during patient setup, image guidance, and treatment on the linear accelerator. For these patients, a thin foam pad or mattress is sometimes used to mitigate patient discomfort. It was desired to quantify the effect of the padding in cases in which the patient is to be treated supine with posterior beams when the majority of the beam weighting traverses both the couch and the pad. Ion chamber measurements in-phantom were acquired with 6 MV, 10 MV, and 15 MV photon beams. At depths of maximum dose, the pad resulted in a difference of signal collected ≤1%. At the phantom surface, the pad resulted in an increase in signal ranging from 1% to 6.5% for the measured beams. CT data of the pad, both with and without applied pressure, indicated that the pad had average HU values close to air.
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Affiliation(s)
- Jessica M Fagerstrom
- Northwest Medical Physics Center, Lynnwood, WA, 98036; Kaiser Permanente, Seattle, WA, 98112.
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Saez J, Bar-Deroma R, Bogaert E, Cayez R, Chow T, Clark CH, Esposito M, Feygelman V, Monti AF, Garcia-Miguel J, Gershkevitsh E, Goossens J, Herrero C, Hussein M, Khamphan C, Kierkels RGJ, Lechner W, Lemire M, Nevelsky A, Nguyen D, Paganini L, Pasler M, Fernando Pérez Azorín J, Ramos Garcia LI, Russo S, Shakeshaft J, Vieillevigne L, Hernandez V. Universal evaluation of MLC models in treatment planning systems based on a common set of dynamic tests. Radiother Oncol 2023; 186:109775. [PMID: 37385376 DOI: 10.1016/j.radonc.2023.109775] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2023] [Revised: 06/19/2023] [Accepted: 06/23/2023] [Indexed: 07/01/2023]
Abstract
PURPOSE To demonstrate the feasibility of characterising MLCs and MLC models implemented in TPSs using a common set of dynamic beams. MATERIALS AND METHODS A set of tests containing synchronous (SG) and asynchronous sweeping gaps (aSG) was distributed among twenty-five participating centres. Doses were measured with a Farmer-type ion chamber and computed in TPSs, which provided a dosimetric characterisation of the leaf tip, tongue-and-groove, and MLC transmission of each MLC, as well as an assessment of the MLC model in each TPS. Five MLC types and four TPSs were evaluated, covering the most frequent combinations used in radiotherapy departments. RESULTS Measured differences within each MLC type were minimal, while large differences were found between MLC models implemented in clinical TPSs. This resulted in some concerning discrepancies, especially for the HD120 and Agility MLCs, for which differences between measured and calculated doses for some MLC-TPS combinations exceeded 10%. These large differences were particularly evident for small gap sizes (5 and 10 mm), as well as for larger gaps in the presence of tongue-and-groove effects. A much better agreement was found for the Millennium120 and Halcyon MLCs, differences being within ± 5% and ± 2.5%, respectively. CONCLUSIONS The feasibility of using a common set of tests to assess MLC models in TPSs was demonstrated. Measurements within MLC types were very similar, but TPS dose calculations showed large variations. Standardisation of the MLC configuration in TPSs is necessary. The proposed procedure can be readily applied in radiotherapy departments and can be a valuable tool in IMRT and credentialing audits.
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Affiliation(s)
- Jordi Saez
- Hospital Clínic de Barcelona, Department of Radiation Oncology, Barcelona, Spain.
| | - Raquel Bar-Deroma
- Rambam Health Care Campus, Department of Radiotherapy, Division of Oncology, Haifa, Israel
| | - Evelien Bogaert
- Ghent University Hospital and Ghent University, Department of Radiation Oncology, Ghent, Belgium
| | - Romain Cayez
- Oscar Lambret Center, Department of Medical Physics, Lille, France
| | - Tom Chow
- Juravinski Hospital and Cancer Centre at Hamilton Health Sciences, Department of Medical Physics, Ontario, Canada
| | - Catharine H Clark
- National Physical Laboratory, Metrology for Medical Physics Centre, London TW11 0PX, UK; Radiotherapy Physics, University College London Hospital, 250 Euston Rd, London NW1 2PG, UK; Dept Medical Physics and Bioengineering, University College London, Malet Place, London WC1 6BT, UK
| | - Marco Esposito
- AUSL Toscana Centro, Medical Physics Unit, Florence, Italy; The Abdus Salam International Center for Theoretical, Trieste, Italy
| | | | - Angelo F Monti
- ASST GOM Niguarda, Department of Medical Physics, Milano, Italy
| | - Julia Garcia-Miguel
- Consorci Sanitari de Terrassa, Department of Radiation Oncology, Terrassa, Spain
| | - Eduard Gershkevitsh
- North Estonia Medical Centre, Department of Medical Physics, Tallinn, Estonia
| | - Jo Goossens
- Iridium Netwerk, Department of Medical Physics, Antwerp, Belgium
| | - Carmen Herrero
- Centro Médico de Asturias-IMOMA, Department of Medical Physics, Oviedo, Spain
| | - Mohammad Hussein
- National Physical Laboratory, Metrology for Medical Physics Centre, London TW11 0PX, UK
| | - Catherine Khamphan
- Institut du Cancer - Avignon Provence, Department of Medical Physics, Avignon, France
| | - Roel G J Kierkels
- Radiotherapiegroep, Department of Medical Physics, Arnhem/Deventer, the Netherlands
| | - Wolfgang Lechner
- Medical University of Vienna, Department of Radiation Oncology, Vienna, Austria
| | - Matthieu Lemire
- CIUSSS de l'Est-de-l'Île-de-Montréal, Service de Radio-Physique, Montréal, Canada
| | - Alexander Nevelsky
- Rambam Health Care Campus, Department of Radiotherapy, Division of Oncology, Haifa, Israel
| | | | - Lucia Paganini
- Humanitas Clinical and Research Center, Radiotherapy and Radiosurgery Department, Rozzano, Italy
| | - Marlies Pasler
- Lake Constance Radiation Oncology Center, Department of Radiation Oncology, Singen, Friedrichshafen, Germany; Radiotherapy Hirslanden, St. Gallen, Switzerland
| | - José Fernando Pérez Azorín
- Medical Physics and Radiation Protection Department, Gurutzeta-Cruces University Hospital, Barakaldo, Spain; Biocruces Health Research Institute, Barakaldo, Spain
| | | | | | - John Shakeshaft
- Gold Coast University Hospital, ICON Cancer Centre, Gold Coast, Australia
| | - Laure Vieillevigne
- Institut Claudius Regaud-Institut Universitaire du Cancer de Toulouse, Department of Medical Physics, Toulouse, France
| | - Victor Hernandez
- Hospital Sant Joan de Reus, Department of Medical Physics, Reus, Spain; Universitat Rovira i Virgili, Tarragona, Spain
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Decoene C, Crop F. Using density computed tomography images for photon dose calculations in radiation oncology: A patient study. Phys Imaging Radiat Oncol 2023; 27:100463. [PMID: 37497189 PMCID: PMC10366581 DOI: 10.1016/j.phro.2023.100463] [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: 03/21/2023] [Revised: 06/20/2023] [Accepted: 06/20/2023] [Indexed: 07/28/2023] Open
Abstract
Background and purpose Conventional workflows for dose calculations require conversions between Hounsfield Units (HU) and the mass or electron density for Computed Tomography (CT) images in the Treatment Planning System (TPS). These conversions are scanner- and mostly kVp-dependent. A density representation or reconstruction at the CT level can potentially simplify the workflow. This study aimed to investigate the agreement between these two methods for patients and different calculation algorithms. Materials and methods Density conversions for conventional HU-density conversions were first established using two phantoms with appropriate inserts. Next, the differences in density and dose calculations between both methods were assessed using 95% Limits of Agreement (LOA) Bland-Altman analysis for 44 consecutive clinical patient cases. These cases represented a mix of indications, algorithms (collapsed cone, convolution superposition, ray tracing, finite-size pencil beam, and Monte Carlo), and scan kVp (80 to 140) in two different commercial TPS. Results No statistically significant bias in density or dose calculations was found between the two methods. Furthermore, 95% LOAs between both methods were ±0.05 g/cm3 and ±0.1 Gy for density and dose, respectively. Small but clinically irrelevant dose differences were found in high-density gradient regions for convolution superposition calculations or CT scans with non-delayed contrast agent injections with targets nearby vessels. Conclusions The in vivo density-reconstructed images at the CT level were assessed to be equivalent. Therefore, they can simplify and improve clinical workflows, allowing patient-specific acquisitions for contouring and density-reconstructed images for dose calculations.
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Affiliation(s)
- Camille Decoene
- Corresponding author at: Service of Medical physics, Centre Oscar Lambret, 3, Rue Frédéric Combemale, Lille 59000.
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Manco L, Vega K, Maffei N, Gutierrez MV, Cenacchi E, Bernabei A, Bruni A, D'angelo E, Meduri B, Lohr F, Guidi G. Validation of RayStation Monte Carlo dose calculation algorithm for multiple LINACs. Phys Med 2023; 109:102588. [PMID: 37080156 DOI: 10.1016/j.ejmp.2023.102588] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/08/2022] [Revised: 03/29/2023] [Accepted: 04/10/2023] [Indexed: 04/22/2023] Open
Abstract
PURPOSE A photon Monte Carlo (MC) model was commissioned for flattened (FF) and flattening filter free (FFF) 6 MV beam energy. The accuracy of this model, as a single model to be used for three beam matched LINACs, was evaluated. METHODS Multiple models were created in RayStation v.10A for three linacs equipped with Elekta "Agility" collimator. A clinically commissioned collapsed cone (CC) algorithm (GoldCC), a MC model automatically created from the CC algorithm without further optimization (CCtoMC) and an optimized MC model (GoldMC) were compared with measurements. The validation of the model was performed by following the recommendations of IAEA TRS 430 and comprised of basic validation in a water tank, validation in a heterogeneous phantom and validation of complex IMRT/VMAT paradigms using gamma analysis of calculated and measured dose maps in a 2D-Array. RESULTS Dose calculation with the GoldMC model resulted in a confidence level of 3% for point measurements in water tank and heterogeneous phantom for measurements performed in all three linacs. The same confidence level resulted for GoldCC model. Dose maps presented an agreement for all models on par to each other with γ criteria 2%/2mm. CONCLUSIONS The GoldMC model showed a good agreement with measured data and is determined to be accurate for clinical use for all three linacs in this study.
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Affiliation(s)
- Luigi Manco
- Medical Physics Unit, University Hospital of Modena, 41125 Modena, Italy; Medical Physics Unit, Azienda USL of Ferrara, 44124 Ferrara, Italy.
| | - Kevin Vega
- International Center of Theoretical Physics, Trieste, Italy; Centro Nacional de Radioterapia, Physics Unit, San Salvador, El Salvador
| | - Nicola Maffei
- Medical Physics Unit, University Hospital of Modena, 41125 Modena, Italy
| | | | - Elisa Cenacchi
- Medical Physics Unit, University Hospital of Modena, 41125 Modena, Italy
| | - Annalisa Bernabei
- Medical Physics Unit, University Hospital of Modena, 41125 Modena, Italy
| | - Alessio Bruni
- Radiation Therapy Unit, Department of Oncology and Hematology, University Hospital of Modena, Modena, Italy
| | - Elisa D'angelo
- Radiation Therapy Unit, Department of Oncology and Hematology, University Hospital of Modena, Modena, Italy
| | - Bruno Meduri
- Radiation Therapy Unit, Department of Oncology and Hematology, University Hospital of Modena, Modena, Italy
| | - Frank Lohr
- Radiation Therapy Unit, Department of Oncology and Hematology, University Hospital of Modena, Modena, Italy
| | - Gabriele Guidi
- Medical Physics Unit, University Hospital of Modena, 41125 Modena, Italy
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