Towards robust deep learning-based autosegmentation in MRI-planned gynecological brachytherapy: Importance of scalable development and comprehensive evaluation
{"title":"Towards robust deep learning-based autosegmentation in MRI-planned gynecological brachytherapy: Importance of scalable development and comprehensive evaluation","authors":"Patricia Jule Oliva , Shrimanti Ghosh , Fleur Huang , Ericka Wiebe , Julie Cuartero , Sunita Ghosh , Pierre Boulanger , Jihyun Yun , Kumaradevan Punithakumar , Geetha Menon","doi":"10.1016/j.brachy.2025.12.007","DOIUrl":null,"url":null,"abstract":"<div><h3>PURPOSE</h3><div>To present comprehensive development and evaluation methodologies for a generalizable deep learning (DL)-driven autocontouring model of standard pelvic organs-at-risk (OARs) in MRI-planned cervical brachytherapy.</div></div><div><h3>MATERIALS AND METHODS</h3><div>A curated dataset of 200 3D-MRIs (85% training/validation, 15% testing) including multiple applicator types, varying treated anatomies, and manual contours of OARs (bladder, rectum, sigmoid, small bowel) by 3 physicians was utilized to develop an nnU-Net-based autocontouring model. Iterative tuning was conducted to determine the optimal hyperparameters and enhance evaluation metrics. Model performance was assessed using quantitative metrics, like geometric (e.g., Dice Coefficient (DC) and Hausdorff Distance 95th Percentile (HD95)) and dosimetric (dose-volume histograms (DVHs), dose differences (ΔD2cc)), and then correlated with qualitative physician-review (modified Turing and Likert tests).</div></div><div><h3>RESULTS</h3><div>Geometric metrics were best for bladder (e.g., mean ± SD DC|HD95(mm) 0.93 ± 0.02|2.26 ± 1.07) with greater variability exhibited for small bowel (0.62 ± 0.16|24.90 ± 14.36). Dosimetric comparisons of manual vs predicted contours showed high agreement in DVHs, with mean ΔD2cc <0.60 Gy EQD2<sub>3</sub> across all OARs. Model performance was consistent, irrespective of applicator type, OAR volume, or contourer. Quantitative scores in support of DLM were not always associated with as favorable qualitative results, yet physician-review showed clinical acceptability (80% for bladder and rectum).</div></div><div><h3>CONCLUSION</h3><div>The DL-based autocontouring model, trained on a heterogeneous in-house dataset, demonstrates clinical acceptability for OARs as determined by comprehensive evaluation. It also shows promise for translatability to target contouring, and adaptability to other gynecological (noncervix) brachytherapy applications. Differences in qualitative and quantitative results exist; directionality and magnitude should be considered in clinical usability assessments of brachytherapy autocontouring models.</div></div>","PeriodicalId":55334,"journal":{"name":"Brachytherapy","volume":"25 2","pages":"Pages 361-372"},"PeriodicalIF":1.8000,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Brachytherapy","FirstCategoryId":"3","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S1538472125003770","RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"2026/1/21 0:00:00","PubModel":"Epub","JCR":"Q4","JCRName":"ONCOLOGY","Score":null,"Total":0}
引用次数: 0
Abstract
PURPOSE
To present comprehensive development and evaluation methodologies for a generalizable deep learning (DL)-driven autocontouring model of standard pelvic organs-at-risk (OARs) in MRI-planned cervical brachytherapy.
MATERIALS AND METHODS
A curated dataset of 200 3D-MRIs (85% training/validation, 15% testing) including multiple applicator types, varying treated anatomies, and manual contours of OARs (bladder, rectum, sigmoid, small bowel) by 3 physicians was utilized to develop an nnU-Net-based autocontouring model. Iterative tuning was conducted to determine the optimal hyperparameters and enhance evaluation metrics. Model performance was assessed using quantitative metrics, like geometric (e.g., Dice Coefficient (DC) and Hausdorff Distance 95th Percentile (HD95)) and dosimetric (dose-volume histograms (DVHs), dose differences (ΔD2cc)), and then correlated with qualitative physician-review (modified Turing and Likert tests).
RESULTS
Geometric metrics were best for bladder (e.g., mean ± SD DC|HD95(mm) 0.93 ± 0.02|2.26 ± 1.07) with greater variability exhibited for small bowel (0.62 ± 0.16|24.90 ± 14.36). Dosimetric comparisons of manual vs predicted contours showed high agreement in DVHs, with mean ΔD2cc <0.60 Gy EQD23 across all OARs. Model performance was consistent, irrespective of applicator type, OAR volume, or contourer. Quantitative scores in support of DLM were not always associated with as favorable qualitative results, yet physician-review showed clinical acceptability (80% for bladder and rectum).
CONCLUSION
The DL-based autocontouring model, trained on a heterogeneous in-house dataset, demonstrates clinical acceptability for OARs as determined by comprehensive evaluation. It also shows promise for translatability to target contouring, and adaptability to other gynecological (noncervix) brachytherapy applications. Differences in qualitative and quantitative results exist; directionality and magnitude should be considered in clinical usability assessments of brachytherapy autocontouring models.
期刊介绍:
Brachytherapy is an international and multidisciplinary journal that publishes original peer-reviewed articles and selected reviews on the techniques and clinical applications of interstitial and intracavitary radiation in the management of cancers. Laboratory and experimental research relevant to clinical practice is also included. Related disciplines include medical physics, medical oncology, and radiation oncology and radiology. Brachytherapy publishes technical advances, original articles, reviews, and point/counterpoint on controversial issues. Original articles that address any aspect of brachytherapy are invited. Letters to the Editor-in-Chief are encouraged.