AI-assisted Contour Editing (AIACE)
model2026-01-24https://doi.org/10.1148/atlas.1769274440844
50

Overview

Schema Version

https://atlas.rsna.org/schemas/2025-11/model.json

Name

AI-assisted Contour Editing (AIACE)

Link

https://pubmed.ncbi.nlm.nih.gov/36204538/

Indexing

Keywords: AI-assisted contour editing, interactive segmentation, U-Net, head and neck, organs at risk, radiotherapy planning, Dice similarity coefficient, Hausdorff distance
Content: CT, RO
RadLex: RID39262, RID10321

Author(s)

Ti Bai
Anjali Balagopal
Michael Dohopolski
Howard E. Morgan
Rafe McBeth
Jun Tan
Mu-Han Lin
David J. Sher
Dan Nguyen
Steve Jiang

Organization(s)

Department of Radiation Oncology, University of Texas Southwestern Medical Center
Department of Radiation Oncology, University of Pennsylvania

Version

1.0

Contact

Steve Jiang, Department of Radiation Oncology, University of Texas Southwestern Medical Center; email: ude.nretsewhtuoSTU@gnaiJ.evetS

Ethical review

For the UTSW test dataset: IRB-approved and de-identified; informed consent waived because data were collected retrospectively with minimal risk.

Date

Updated: 2022-07-14
Published: 2022-08-03
Created: 2021-08-04

References

[1] Bai T, Balagopal A, Dohopolski M, Morgan HE, McBeth R, Tan J, Lin M-H, Sher DJ, Nguyen D, Jiang S. "A Proof-of-Concept Study of Artificial Intelligence–assisted Contour Editing". Radiology: Artificial Intelligence. 2022 Sep;4(5):e210214.. 2022-09-01. doi:10.1148/ryai.210214. PMID: 36204538. PMCID: PMC9530760.

Model

Architecture

U-Net–based deep convolutional neural network for interactive contour editing (three-channel input: original CT slice, current segmentation mask, and click image; output: updated mask).

Availability

Not stated.

Clinical benefit

Assists clinicians in efficiently and effectively editing organs-at-risk contours for radiotherapy planning, reducing manual editing time and improving contour quality, including in online adaptive radiotherapy workflows.

Clinical workflow phase

Clinical decision support and workflow optimization for contour editing during treatment planning/online adaptive radiotherapy.

Decision threshold

For failure analysis, an example quality threshold was HD95 < 2.5 mm within 20 clicks.

Degree of automation

Interactive assistance; clinician-in-the-loop with iterative clicks guiding automated contour updates.

Indications for use

Editing of head-and-neck organs-at-risk contours on axial CT images for radiotherapy planning; intended for use by clinicians in radiation oncology settings.

Input

2D axial head-and-neck CT image slice; current segmentation mask; clinician-provided click image (Gaussian around clicked boundary point).

Instructions

Start from an automatically generated initial contour; at each iteration, the clinician clicks on the boundary location with the largest perceived error. The click is converted to a Gaussian point in a click image (radius ~10 pixels). Provide the three-channel input (image, current mask, click image) to the model to obtain an updated contour. Repeat until clinically acceptable.

Limitations

Proof-of-concept using 2D axial images only; clinician interactions simulated during training/testing; performance reported with simulated clicks placed at largest-error boundary points (upper bound of performance); occasional failures when successive clicks provide insufficient new information; model trained and evaluated on head-and-neck CT data; generalization beyond studied organs/modalities not demonstrated.

Output

CDEs: RDE2035, RDE2519
Description: Updated segmentation mask for organs at risk on the current CT slice after each clinician click.

Recommendation

Use downstream of an automatic segmentation model to iteratively correct contours with minimal clicks; not a replacement for fully automatic segmentation.

Reproducibility

Five independently trained models with different random seeds showed consistent improvements across datasets; datasets and parameter settings described; training/validation data sources publicly available.

Sustainability

Real-time interaction feasible; ~20 ms per iteration on a single NVIDIA GeForce Titan X GPU.

Use

Intended: Image segmentation
Out-of-scope: Image segmentation, Detection and diagnosis

User

Intended: Other
Out-of-scope: Layperson