{"title":"Prior Knowledge-Guided U-Net for Automatic CTV Segmentation in Postmastectomy Radiotherapy of Breast Cancer.","authors":"Xiu-Wen Deng, Hong-Mei Zhao, Le-Cheng Jia, Jin-Na Li, Ziquan Wei, Hang Yang, Ang Qu, Wei-Juan Jiang, Run-Hong Lei, Hai-Tao Sun, Jun-Jie Wang, Ping Jiang","doi":"10.1016/j.ijrobp.2024.11.104","DOIUrl":null,"url":null,"abstract":"<p><strong>Purpose: </strong>This study aimed to design and evaluate a prior-knowledge-guided U-Net (PK-UNet) for automatic clinical target volume (CTV) segmentation in postmastectomy radiotherapy for breast cancer.</p><p><strong>Methods and materials: </strong>A total of 102 computed tomography (CT) scans from breast cancer patients who underwent postmastectomy were retrospectively collected. Of these, 80 scans were used for training with 5-fold cross-validation, and 22 scans for independent testing. The CTV included the chest wall, supraclavicular region, and axillary group III. The proposed PK-UNet method employs a two-stage auto-segmentation process. Initially, the localization network categorizes CT slices based on the anatomical information of the CTV and generates prior knowledge labels. These outputs, along with the CT images, were fed into the final segmentation network. Quantitative evaluation was conducted using the mean Dice similarity coefficient (DSC), 95% Hausdorff distance (95HD), average surface distance (ASD), surface Dice similarity coefficient (sDSC). A four-level objective scale evaluation was performed by two experienced radiation oncologists in a randomized, double-blind manner.</p><p><strong>Results: </strong>Quantitative evaluations revealed that PK-UNet significantly outperformed state-of-the-art (SOTA) segmentation methods (P < 0.01), with a mean DSC of 0.90 ± 0.02 and a 95HD of 2.82 ± 1.29 mm. The mean ASD of PK-UNet was 0.91 ± 0.22 mm and the sDSC was 0.84 ± 0.07, significantly surpassing the performance of AdwU-Net (P < 0.01) and showing comparable results to other models. Clinical evaluation confirmed the efficacy of PK-UNet, with 81.8% of the predicted contours being acceptable for clinical application. The advantages of the auto-segmentation capability of PK-UNet were most evident in the superior and inferior slices and slices with discontinuities at the junctions of different subregions. The average manual correction time was reduced to 1.02 min, compared to 18.20 min for manual contouring leading to a 94.4% reduction in working time.</p><p><strong>Conclusion: </strong>This study introduced the pioneering integration of prior medical knowledge into a deep learning framework for postmastectomy radiotherapy. This strategy addresses the challenges of CTV segmentation in postmastectomy radiotherapy and improves clinical workflow efficiency.</p>","PeriodicalId":14215,"journal":{"name":"International Journal of Radiation Oncology Biology Physics","volume":" ","pages":""},"PeriodicalIF":6.4000,"publicationDate":"2024-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"International Journal of Radiation Oncology Biology Physics","FirstCategoryId":"3","ListUrlMain":"https://doi.org/10.1016/j.ijrobp.2024.11.104","RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"ONCOLOGY","Score":null,"Total":0}
引用次数: 0
Abstract
Purpose: This study aimed to design and evaluate a prior-knowledge-guided U-Net (PK-UNet) for automatic clinical target volume (CTV) segmentation in postmastectomy radiotherapy for breast cancer.
Methods and materials: A total of 102 computed tomography (CT) scans from breast cancer patients who underwent postmastectomy were retrospectively collected. Of these, 80 scans were used for training with 5-fold cross-validation, and 22 scans for independent testing. The CTV included the chest wall, supraclavicular region, and axillary group III. The proposed PK-UNet method employs a two-stage auto-segmentation process. Initially, the localization network categorizes CT slices based on the anatomical information of the CTV and generates prior knowledge labels. These outputs, along with the CT images, were fed into the final segmentation network. Quantitative evaluation was conducted using the mean Dice similarity coefficient (DSC), 95% Hausdorff distance (95HD), average surface distance (ASD), surface Dice similarity coefficient (sDSC). A four-level objective scale evaluation was performed by two experienced radiation oncologists in a randomized, double-blind manner.
Results: Quantitative evaluations revealed that PK-UNet significantly outperformed state-of-the-art (SOTA) segmentation methods (P < 0.01), with a mean DSC of 0.90 ± 0.02 and a 95HD of 2.82 ± 1.29 mm. The mean ASD of PK-UNet was 0.91 ± 0.22 mm and the sDSC was 0.84 ± 0.07, significantly surpassing the performance of AdwU-Net (P < 0.01) and showing comparable results to other models. Clinical evaluation confirmed the efficacy of PK-UNet, with 81.8% of the predicted contours being acceptable for clinical application. The advantages of the auto-segmentation capability of PK-UNet were most evident in the superior and inferior slices and slices with discontinuities at the junctions of different subregions. The average manual correction time was reduced to 1.02 min, compared to 18.20 min for manual contouring leading to a 94.4% reduction in working time.
Conclusion: This study introduced the pioneering integration of prior medical knowledge into a deep learning framework for postmastectomy radiotherapy. This strategy addresses the challenges of CTV segmentation in postmastectomy radiotherapy and improves clinical workflow efficiency.
期刊介绍:
International Journal of Radiation Oncology • Biology • Physics (IJROBP), known in the field as the Red Journal, publishes original laboratory and clinical investigations related to radiation oncology, radiation biology, medical physics, and both education and health policy as it relates to the field.
This journal has a particular interest in original contributions of the following types: prospective clinical trials, outcomes research, and large database interrogation. In addition, it seeks reports of high-impact innovations in single or combined modality treatment, tumor sensitization, normal tissue protection (including both precision avoidance and pharmacologic means), brachytherapy, particle irradiation, and cancer imaging. Technical advances related to dosimetry and conformal radiation treatment planning are of interest, as are basic science studies investigating tumor physiology and the molecular biology underlying cancer and normal tissue radiation response.