Multitask 3D CBCT-to-CT translation and organs-at-risk segmentation using physics-based data augmentation Journal Article


Authors: Dahiya, N.; Alam, S. R.; Zhang, P.; Zhang, S. Y.; Li, T.; Yezzi, A.; Nadeem, S.
Article Title: Multitask 3D CBCT-to-CT translation and organs-at-risk segmentation using physics-based data augmentation
Abstract: Purpose: In current clinical practice, noisy and artifact-ridden weekly cone beam computed tomography (CBCT) images are only used for patient setup during radiotherapy. Treatment planning is performed once at the beginning of the treatment using high-quality planning CT (pCT) images and manual contours for organs-at-risk (OARs) structures. If the quality of the weekly CBCT images can be improved while simultaneously segmenting OAR structures, this can provide critical information for adapting radiotherapy mid-treatment as well as for deriving biomarkers for treatment response. Methods: Using a novel physics-based data augmentation strategy, we synthesize a large dataset of perfectly/inherently registered pCT and synthetic-CBCT pairs for locally advanced lung cancer patient cohort, which are then used in a multitask three-dimensional (3D) deep learning framework to simultaneously segment and translate real weekly CBCT images to high-quality pCT-like images. Results: We compared the synthetic CT and OAR segmentations generated by the model to real pCT and manual OAR segmentations and showed promising results. The real week 1 (baseline) CBCT images which had an average mean absolute error (MAE) of 162.77 HU compared to pCT images are translated to synthetic CT images that exhibit a drastically improved average MAE of 29.31 HU and average structural similarity of 92% with the pCT images. The average DICE scores of the 3D OARs segmentations are: lungs 0.96, heart 0.88, spinal cord 0.83, and esophagus 0.66. Conclusions: We demonstrate an approach to translate artifact-ridden CBCT images to high-quality synthetic CT images, while simultaneously generating good quality segmentation masks for different OARs. This approach could allow clinicians to adjust treatment plans using only the routine low-quality CBCT images, potentially improving patient outcomes. Our code, data, and pre-trained models will be made available via our physics-based data augmentation library, Physics-ArX, at https://github.com/nadeemlab/Physics-ArX. © 2021 American Association of Physicists in Medicine.
Keywords: treatment response; treatment planning; radiotherapy; image enhancement; computerized tomography; image segmentation; clinical practices; learning frameworks; structural similarity; deep learning; threedimensional (3-d); mean absolute error; large dataset; 3d cbct-to-ct translation; oars segmentation; cone beam computed tomography image (cbct)
Journal Title: Medical Physics
Volume: 48
Issue: 9
ISSN: 0094-2405
Publisher: American Association of Physicists in Medicine  
Date Published: 2021-09-01
Start Page: 5130
End Page: 5141
Language: English
DOI: 10.1002/mp.15083
PUBMED: 34245012
PROVIDER: scopus
PMCID: PMC8455439
DOI/URL:
Notes: Article -- Export Date: 1 October 2021 -- Source: Scopus
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  1. Pengpeng Zhang
    175 Zhang
  2. Tianfang Li
    48 Li
  3. Saad Nadeem
    50 Nadeem