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Approaching automated applicator digitization from a new angle: Using sagittal images to improve deep learning accuracy and robustness in high-dose-rate prostate brachytherapy. Brachytherapy 2022; 21:520-531. [DOI: 10.1016/j.brachy.2022.02.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2021] [Revised: 02/07/2022] [Accepted: 02/26/2022] [Indexed: 11/17/2022]
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Deufel CL, Tian S, Yan BB, Vaishnav BD, Haddock MG, Petersen IA. Automated applicator digitization for high-dose-rate cervix brachytherapy using image thresholding and density-based clustering. Brachytherapy 2019; 19:111-118. [PMID: 31594729 DOI: 10.1016/j.brachy.2019.09.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2019] [Revised: 08/13/2019] [Accepted: 09/09/2019] [Indexed: 10/25/2022]
Abstract
PURPOSE The purpose of the study was to develop and evaluate an automated digitization algorithm for high-dose-rate cervix brachytherapy, with the goal of reducing the duration of treatment planning, staff resources, variability, and potential for human error. METHODS An automated digitization algorithm was developed and retrospectively evaluated using treatment planning data from 10 patients with cervix cancer who were treated with a titanium tandem and ovoids applicator set. Applicators were segmented, without human interaction, by thresholding CT images to isolate high-density voxels and assigning the voxels to applicator and nonapplicator structures using HDBSCAN, a density-based linkage clustering algorithm. The applicator contours were determined from the centroid of the clustered voxels on each image slice and written to a treatment plan file. Automated contours were evaluated against manual digitization using distance and dosimetric metrics. RESULTS A close agreement between automatic and manual digitization was observed. The mean magnitude of contour disagreement for 10 patients equaled 0.3 mm. Hausdorff distances were ≤1.0 mm. The applicator tip coordinates had submillimeter agreement. The median and mean dose volume histogram parameter differences were less than or equal to 1% for high-risk clinical target volume D90, high-risk clinical target volume D95, bladder D2cc, rectum D2cc, large bowel D2cc, and small bowel D2cc. The average execution time for the automated algorithm was less than 30 s. CONCLUSION The digitization of titanium tandem and ovoids applicators for high-dose-rate brachytherapy treatment planning can be automated using straightforward thresholding and clustering algorithms. The adoption of automated digitization is expected to improve the consistency of treatment plans and reduce the duration of treatment planning.
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Affiliation(s)
| | - Shulan Tian
- Division of Biomedical Statistics and Informatics, Department of Health Sciences Research, Mayo Clinic, Rochester, MN
| | - Benjamin B Yan
- Department of Radiation Oncology, Mayo Clinic, Rochester, MN
| | | | | | - Ivy A Petersen
- Department of Radiation Oncology, Mayo Clinic, Rochester, MN
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Binny D, Lancaster CM, Kairn T, Trapp JV, Back P, Cheuk R, Crowe SB. Investigating the use of image thresholding in brachytherapy catheter reconstruction. AUSTRALASIAN PHYSICAL & ENGINEERING SCIENCES IN MEDICINE 2016; 39:913-919. [PMID: 27787758 DOI: 10.1007/s13246-016-0493-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2016] [Accepted: 10/20/2016] [Indexed: 10/20/2022]
Abstract
This study evaluated the accuracy of image thresholding in the reconstruction of catheters in brachytherapy treatment planning systems. Six test cases including four planar catheter configurations, an interstitial prostate and an intracavitary treatment plan were made use of in this study. The four planar CT scanned catheter arrangements included; catheters placed approximately 1, 0.5 cm apart, catheters closely arranged in a plan (<0.5 cm apart) and a loop arrangement. The intracavitary plan consisted of catheters arranged inside a mould configuration. All reconstruction methods were based on tracking wire markers placed inside the plastic catheters. Each of these catheter arrangements was reconstructed using an existing window adjustment technique (manual reconstruction) in the treatment planning system followed by a CT-based automated thresholding technique available in the same planning system. A corresponding reconstructed catheter was created using a segmented catheter structure using image thresholding from another planning system within the same department. Co-ordinates from all the reconstructed catheters were compared against each other to assess the geometric shift between manual and threshold based reconstruction on each transaxial image using in-house software and the maximum variations were recorded for assessment. It was observed in general that automated thresholding technique could assist in catheter reconstruction for catheters which are greater than 0.5 cm apart. The segmented thresholding method reported smaller variations when compared to the manual reconstruction using window adjustment technique. Automated reconstruction saves time in the brachytherapy planning, however it was noted that it is not feasible for closely spaced catheters. Segmented catheter reconstruction although time consuming, did provide a better alternative in most cases.
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Affiliation(s)
- Diana Binny
- Department of Radiation Oncology, Cancer Care Services, Royal Brisbane and Women's Hospital, Level 3, Joyce Tweddell Building, Butterfield Street, Herston, Brisbane, QLD, 4029, Australia. .,Queensland University of Technology, Brisbane, Australia.
| | - Craig M Lancaster
- Department of Radiation Oncology, Cancer Care Services, Royal Brisbane and Women's Hospital, Level 3, Joyce Tweddell Building, Butterfield Street, Herston, Brisbane, QLD, 4029, Australia
| | - Tanya Kairn
- Queensland University of Technology, Brisbane, Australia.,Genesis Cancer Care Queensland, Brisbane, Australia
| | - Jamie V Trapp
- Queensland University of Technology, Brisbane, Australia
| | - Phil Back
- Department of Radiation Oncology, Cancer Care Services, Royal Brisbane and Women's Hospital, Level 3, Joyce Tweddell Building, Butterfield Street, Herston, Brisbane, QLD, 4029, Australia
| | - Robyn Cheuk
- Department of Radiation Oncology, Cancer Care Services, Royal Brisbane and Women's Hospital, Level 3, Joyce Tweddell Building, Butterfield Street, Herston, Brisbane, QLD, 4029, Australia
| | - Scott B Crowe
- Department of Radiation Oncology, Cancer Care Services, Royal Brisbane and Women's Hospital, Level 3, Joyce Tweddell Building, Butterfield Street, Herston, Brisbane, QLD, 4029, Australia.,Queensland University of Technology, Brisbane, Australia
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Milickovic N, Lahanas M, Papagiannopoulo M, Zamboglou N, Baltas D. Multiobjective anatomy-based dose optimization for HDR-brachytherapy with constraint free deterministic algorithms. Phys Med Biol 2002; 47:2263-80. [PMID: 12164586 DOI: 10.1088/0031-9155/47/13/306] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
In high dose rate (HDR) brachytherapy, conventional dose optimization algorithms consider multiple objectives in the form of an aggregate function that transforms the multiobjective problem into a single-objective problem. As a result, there is a loss of information on the available alternative possible solutions. This method assumes that the treatment planner exactly understands the correlation between competing objectives and knows the physical constraints. This knowledge is provided by the Pareto trade-off set obtained by single-objective optimization algorithms with a repeated optimization with different importance vectors. A mapping technique avoids non-feasible solutions with negative dwell weights and allows the use of constraint free gradient-based deterministic algorithms. We compare various such algorithms and methods which could improve their performance. This finally allows us to generate a large number of solutions in a few minutes. We use objectives expressed in terms of dose variances obtained from a few hundred sampling points in the planning target volume (PTV) and in organs at risk (OAR). We compare two- to four-dimensional Pareto fronts obtained with the deterministic algorithms and with a fast-simulated annealing algorithm. For PTV-based objectives, due to the convex objective functions, the obtained solutions are global optimal. If OARs are included, then the solutions found are also global optimal, although local minima may be present as suggested.
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Affiliation(s)
- N Milickovic
- Department of Medical Physics and Engineering, Strahlenklinik, Klinikum Offenbach, Offenbach am Main, Germany.
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