1
|
Mansour IR, Thomson RM. Haralick texture feature analysis for characterization of specific energy and absorbed dose distributions across cellular to patient length scales. Phys Med Biol 2023; 68. [PMID: 36731130 DOI: 10.1088/1361-6560/acb885] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Accepted: 02/02/2023] [Indexed: 02/04/2023]
Abstract
Objective.To investigate an approach for quantitative characterization of the spatial distribution of dosimetric data by introducing Haralick texture feature analysis in this context.Approach.Monte Carlo simulations are used to generate 3D arrays of dosimetric data for 2 scenarios: (1) cell-scale microdosimetry: specific energy (energy imparted per unit mass) in cell-scale targets irradiated by photon spectra (125I,192Ir, 6 MV); (2) tumour-scale dosimetry: absorbed dose in voxels for idealized models of125I permanent implant prostate brachytherapy, considering 'TG186' (realistic tissues including 0% to 5% intraprostatic calcifications; interseed attenuation) and 'TG43' (water model, no interseed attenuation) conditions. Five prominent Haralick features (homogeneity, contrast, correlation, local homogeneity, entropy) are computed and trends are interpreted using fundamental radiation physics.Main results.In the cell-scale scenario, the Haralick measures quantify differences in 3D specific energy distributions due to source spectra. For example, contrast and entropy are highest for125I reflecting the large variations in specific energy in adjacent voxels (photoelectric interactions; relatively short range of electrons), while 6 MV has the highest homogeneity with smaller variations in specific energy between voxels (Compton scattering dominates; longer range of electrons). For the tumour-scale scenario, the Haralick measures quantify differences due to TG186/TG43 simulation conditions and the presence of calcifications. For example, as calcifications increase from 0% to 5%, contrast increases while correlation decreases, reflecting the large differences in absorbed dose in adjacent voxels (higher absorbed dose in voxels with calcification due to photoelectric interactions).Significance.Haralick texture analysis provides a quantitative method for the characterization of 3D dosimetric distributions across cellular to tumour length scales, with promising future applications including analyses of multiscale tissue models, patient-specific data, and comparison of treatment approaches.
Collapse
Affiliation(s)
- Iymad R Mansour
- Carleton Laboratory for Radiotherapy Physics, Physics Department, Carleton University, 1125 Colonel By Dr, Ottawa, K1S 5B6, Ontario, Canada
| | - Rowan M Thomson
- Carleton Laboratory for Radiotherapy Physics, Physics Department, Carleton University, 1125 Colonel By Dr, Ottawa, K1S 5B6, Ontario, Canada
| |
Collapse
|
2
|
Safigholi H, Chamberland MJP, Taylor REP, Martinov MP, Rogers DWO, Thomson RM. Update of the CLRP Monte Carlo TG-43 parameter database for high-energy brachytherapy sources. Med Phys 2023; 50:1928-1941. [PMID: 36542404 DOI: 10.1002/mp.16176] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2022] [Revised: 11/11/2022] [Accepted: 12/06/2022] [Indexed: 12/24/2022] Open
Abstract
PURPOSE To update and extend version 2 of the Carleton Laboratory for Radiotherapy Physics (CLRP) TG-43 dosimetry database (CLRP_TG43v2) for high-energy (HE, ≥50 keV) brachytherapy sources (1 169 Yb, 23 192 Ir, 5 137 Cs, and 4 60 Co) using egs_brachy, an open-source EGSnrc application. A comprehensive dataset of TG-43 parameters is compiled, including detailed source descriptions, dose-rate constants, radial dose functions, 1D and 2D anisotropy functions, along-away dose-rate tables, Primary and Scatter Separated (PSS) dose tables, and mean photon energies escaping each source. The database also documents the source models which are freely distributed with egs_brachy. ACQUISITION AND VALIDATION METHODS Datasets are calculated after a recoding of the source geometries using the egs++ geometry package and its egs_brachy extensions. Air kerma per history is calculated in a 10 × 10 × $\,{\times}\, 10\,{\times}\,$ 0.05 cm3 voxel located 100 cm from the source along the transverse axis and then corrected for the lateral and thickness dimensions of the scoring voxel to give the air kerma on the central axis at a point 100 cm from the source's mid-point. Full-scatter water phantoms with varying voxel resolutions in cylindrical coordinates are used for dose calculations. Most data (except for 60 Co) are based on the assumption of charged particle equilibrium and ignore the potentially large effects of electron transport very close to the source and dose from initial beta particles. These effects are evaluated for four representative sources. For validation, data are compared to those from CLRP_TG43v1 and published data. DATA FORMAT AND ACCESS Data are available at https://physics.carleton.ca/clrp/egs_brachy/seed_database_v2 or http://doi.org/10.22215/clrp/tg43v2 including in Excel (.xlsx) spreadsheets, and are presented graphically in comparisons to previously published data for each source. POTENTIAL APPLICATIONS The CLRP_TG43v2 database has applications in research, dosimetry, and brachytherapy planning. This comprehensive update provides the medical physics community with more precise and in some cases more accurate Monte Carlo (MC) TG-43 dose calculation parameters, as well as fully benchmarked and described source models which are distributed with egs_brachy.
Collapse
Affiliation(s)
- Habib Safigholi
- Carleton Laboratory for Radiotherapy Physics (CLRP), Department of Physics, Carleton University, Ottawa, Ontario, Canada
| | - Marc J P Chamberland
- Carleton Laboratory for Radiotherapy Physics (CLRP), Department of Physics, Carleton University, Ottawa, Ontario, Canada
| | - Randle E P Taylor
- Carleton Laboratory for Radiotherapy Physics (CLRP), Department of Physics, Carleton University, Ottawa, Ontario, Canada
| | - Martin P Martinov
- Carleton Laboratory for Radiotherapy Physics (CLRP), Department of Physics, Carleton University, Ottawa, Ontario, Canada
| | - D W O Rogers
- Carleton Laboratory for Radiotherapy Physics (CLRP), Department of Physics, Carleton University, Ottawa, Ontario, Canada
| | - Rowan M Thomson
- Carleton Laboratory for Radiotherapy Physics (CLRP), Department of Physics, Carleton University, Ottawa, Ontario, Canada
| |
Collapse
|
3
|
Safigholi H, Parsons Z, Deering SG, Thomson RM. Update of the CLRP eye plaque brachytherapy database for photon-emitting sources. Med Phys 2021; 48:3373-3283. [PMID: 33735471 DOI: 10.1002/mp.14844] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Revised: 02/04/2021] [Accepted: 03/10/2021] [Indexed: 12/12/2022] Open
Abstract
PURPOSE To update and extend the Carleton Laboratory for Radiotherapy Physics (CLRP) Eye Plaque (EP) dosimetry database for low-energy photon-emitting brachytherapy sources using egs_brachy, an open-source EGSnrc application. The previous database, CLRP_EPv1, contained datasets for the Collaborative Ocular Melanoma Study (COMS) plaques (10-22 mm diameter) with 103 Pd or 125 I seeds (BrachyDose-computed, 2008). The new database, CLRP_EPv2, consists of newly calculated three-dimensional (3D) dose distributions for 17 plaques [eight COMS, five Eckert & Ziegler BEBIG, and four others representative of models used worldwide] for 103 Pd, 125 I, and 131 Cs seeds. ACQUISITION AND VALIDATION METHODS Plaque models are developed with egs_brachy, based on published/manufacturer dimensions and material data. The BEBIG plaques (modeled for the first time) are identical in dimensions to COMS plaques but differ in elemental composition and/or density. Previously benchmarked seed models are used. Eye plaques and seeds are simulated at the center of full-scatter water phantoms, scoring in (0.05 cm)3 voxels spanning the eye for scenarios: (a) "HOMO": simulated TG43 conditions; (b) "HETERO": eye plaques and seeds fully modeled; (c) "HETsi" (BEBIG only): one seed is active at a time with other seed geometries present but not emitting photons (inactive); summation over all i seeds in a plaque then yields "HETsum" (includes interseed effects). For validation, doses are compared to those from CLRP_EPv1 and published data. DATA FORMAT AND ACCESS Data are available at https://physics.carleton.ca/clrp/eye_plaque_v2, http://doi.org/10.22215/clrp/EPv2. The data consist of 3D dose distributions (text-based EGSnrc "3ddose" file format) and graphical presentations of the comparisons to previously published data. POTENTIAL APPLICATIONS The CLRP_EPv2 database provides accurate reference 3D dose distributions to advance ocular brachytherapy dose evaluations. The fully-benchmarked eye plaque models will be freely distributed with egs_brachy, supporting adoption of model-based dose evaluations as recommended by TG-129, TG-186, and TG-221.
Collapse
Affiliation(s)
- Habib Safigholi
- Carleton Laboratory for Radiotherapy Physics, Department of Physics, Carleton University, Ottawa, ON, K1S 5B6, Canada
| | - Zack Parsons
- Carleton Laboratory for Radiotherapy Physics, Department of Physics, Carleton University, Ottawa, ON, K1S 5B6, Canada
| | - Stephen G Deering
- Carleton Laboratory for Radiotherapy Physics, Department of Physics, Carleton University, Ottawa, ON, K1S 5B6, Canada
| | - Rowan M Thomson
- Carleton Laboratory for Radiotherapy Physics, Department of Physics, Carleton University, Ottawa, ON, K1S 5B6, Canada
| |
Collapse
|
4
|
Deering SG, Hilts M, Batchelar D, Crook J, Thomson RM. Dosimetric investigation of 103Pd permanent breast seed implant brachytherapy based on Monte Carlo calculations. Brachytherapy 2021; 20:686-694. [PMID: 33551273 DOI: 10.1016/j.brachy.2020.12.009] [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: 08/02/2020] [Revised: 12/03/2020] [Accepted: 12/19/2020] [Indexed: 10/22/2022]
Abstract
PURPOSE Permanent breast seed implant using 103Pd is emerging as an effective adjuvant radiation technique for early stage breast cancer. However, clinical dose evaluations follow the water-based TG-43 approach with its considerable approximations. Toward clinical adoption of advanced TG-186 model-based dose evaluations, this study presents a comprehensive investigation for permanent breast seed implant considering both target and normal tissue doses. METHODS AND MATERIALS Dose calculations are performed with the free open-source Monte Carlo (MC) code, egs_brachy, using two types of virtual patient models: TG43sim (simulated TG-43 conditions) and MCref (heterogeneous tissue modeling from patient CT, seeds at implant angle) for 35 patients. The sensitivity of dose metrics to seed orientation and tissue segmentation are assessed. RESULTS In the target volume, D90 is 14.1 ± 5.8% lower with MCref than with TG43sim, on average. Conversely, normal tissue doses are generally higher with MCref than with TG43sim, for example, by 22 ± 13% for skin D1cm2, 82 ± 7% for ribs Dmax, and 71 ± 23% for heart D1cm3. Discrepancies between MCref and TG43sim doses vary over the patient cohort, as well as with the tissue and metric considered. Skin doses are particularly sensitive to seed orientation, with average difference of 4% (maximum 28%) in D1cm2 for seeds modeled vertically (egs_brachy default) compared with those aligned with implant angle. CONCLUSIONS TG-43 dose evaluations generally underestimate doses to critical normal organs/tissues while overestimating target doses. There is considerable variation in MCref and TG43sim on a patient-by-patient basis, motivating clinical adoption of patient-specific MC dose calculations. The MCref framework presented herein provides a consistent modeling approach for clinical implementation of advanced TG-186 dose calculations.
Collapse
Affiliation(s)
- Stephen G Deering
- Carleton Laboratory for Radiotherapy Physics, Department of Physics, Carleton University, Ottawa, Canada
| | - Michelle Hilts
- Department of Medical Physics, BC Cancer-Kelowna, Kelowna, British Columbia, Canada; Department of Physics, IK Barber School of Arts and Sciences, University of British Columbia-Okanagan, Kelowna, British Columbia, Canada
| | - Deidre Batchelar
- Department of Medical Physics, BC Cancer-Kelowna, Kelowna, British Columbia, Canada; Department of Physics, IK Barber School of Arts and Sciences, University of British Columbia-Okanagan, Kelowna, British Columbia, Canada
| | - Juanita Crook
- Department of Radiation Oncology, BC Cancer-Kelowna, Kelowna, British Columbia, Canada
| | - Rowan M Thomson
- Carleton Laboratory for Radiotherapy Physics, Department of Physics, Carleton University, Ottawa, Canada.
| |
Collapse
|
5
|
Safigholi H, Chamberland MJP, Taylor REP, Allen CH, Martinov MP, Rogers DWO, Thomson RM. Update of the CLRP TG‐43 parameter database for low‐energy brachytherapy sources. Med Phys 2020; 47:4656-4669. [DOI: 10.1002/mp.14249] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2020] [Revised: 06/08/2020] [Accepted: 05/05/2020] [Indexed: 12/23/2022] Open
Affiliation(s)
- Habib Safigholi
- Carleton Laboratory for Radiotherapy Physics (CLRP) Department of Physics Carleton University Ottawa ON K1S 5B6 Canada
| | - Marc J. P. Chamberland
- Carleton Laboratory for Radiotherapy Physics (CLRP) Department of Physics Carleton University Ottawa ON K1S 5B6 Canada
| | - Randle E. P. Taylor
- Carleton Laboratory for Radiotherapy Physics (CLRP) Department of Physics Carleton University Ottawa ON K1S 5B6 Canada
| | - Christian H. Allen
- Carleton Laboratory for Radiotherapy Physics (CLRP) Department of Physics Carleton University Ottawa ON K1S 5B6 Canada
| | - Martin P. Martinov
- Carleton Laboratory for Radiotherapy Physics (CLRP) Department of Physics Carleton University Ottawa ON K1S 5B6 Canada
| | - D. W. O. Rogers
- Carleton Laboratory for Radiotherapy Physics (CLRP) Department of Physics Carleton University Ottawa ON K1S 5B6 Canada
| | - Rowan M. Thomson
- Carleton Laboratory for Radiotherapy Physics (CLRP) Department of Physics Carleton University Ottawa ON K1S 5B6 Canada
| |
Collapse
|
6
|
Thomson RM, Furutani KM, Kaulich TW, Mourtada F, Rivard MJ, Soares CG, Vanneste FM, Melhus CS. AAPM recommendations on medical physics practices for ocular plaque brachytherapy: Report of task group 221. Med Phys 2020; 47:e92-e124. [PMID: 31883269 DOI: 10.1002/mp.13996] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2018] [Revised: 11/12/2019] [Accepted: 12/23/2019] [Indexed: 12/14/2022] Open
Abstract
The American Association of Physicists in Medicine (AAPM) formed Task Group 221 (TG-221) to discuss a generalized commissioning process, quality management considerations, and clinical physics practice standards for ocular plaque brachytherapy. The purpose of this report is also, in part, to aid the clinician to implement recommendations of the AAPM TG-129 report, which placed emphasis on dosimetric considerations for ocular brachytherapy applicators used in the Collaborative Ocular Melanoma Study (COMS). This report is intended to assist medical physicists in establishing a new ocular brachytherapy program and, for existing programs, in reviewing and updating clinical practices. The report scope includes photon- and beta-emitting sources and source:applicator combinations. Dosimetric studies for photon and beta sources are reviewed to summarize the salient issues and provide references for additional study. The components of an ocular plaque brachytherapy quality management program are discussed, including radiation safety considerations, source calibration methodology, applicator commissioning, imaging quality assurance tests for treatment planning, treatment planning strategies, and treatment planning system commissioning. Finally, specific guidelines for commissioning an ocular plaque brachytherapy program, clinical physics practice standards in ocular plaque brachytherapy, and other areas reflecting the need for specialized treatment planning systems, measurement phantoms, and detectors (among other topics) to support the clinical practice of ocular brachytherapy are presented. Expected future advances and developments for ocular brachytherapy are discussed.
Collapse
Affiliation(s)
- Rowan M Thomson
- Carleton Laboratory for Radiotherapy Physics, Physics Department, Carleton University, Ottawa, ON, K1S 5B6, Canada
| | - Keith M Furutani
- Department of Radiation Oncology, Mayo Clinic, Rochester, MN, 55905, USA
| | - Theodor W Kaulich
- Department of Medical Physics, University of Tübingen, 72074, Tübingen, Germany
| | - Firas Mourtada
- Department of Radiation Oncology, Christiana Care Hospital, Newark, DE, 19713, USA
| | - Mark J Rivard
- Department of Radiation Oncology, Warren Alpert Medical School of Brown University, Providence, RI, 02903, USA
| | | | | | - Christopher S Melhus
- Department of Radiation Oncology, Tufts University School of Medicine, Boston, MA, 02111, USA
| |
Collapse
|