Enhancing Precision in Cardiac Segmentation for Magnetic Resonance-Guided Radiation Therapy Through Deep Learning
Recommended Citation
Summerfield N, Morris E, Banerjee S, He Q, Ghanem AI, Zhu S, Zhao J, Dong M, and Glide-Hurst C. Enhancing Precision in Cardiac Segmentation for MR-Guided Radiation Therapy through Deep Learning. Int J Radiat Oncol Biol Phys 2024.
Document Type
Article
Publication Date
11-1-2024
Publication Title
International journal of radiation oncology, biology, physics
Abstract
PURPOSE: Cardiac substructure dose metrics are more strongly linked to late cardiac morbidities than to whole-heart metrics. Magnetic resonance (MR)-guided radiation therapy (MRgRT) enables substructure visualization during daily localization, allowing potential for enhanced cardiac sparing. We extend a publicly available state-of-the-art deep learning framework, "No New" U-Net, to incorporate self-distillation (nnU-Net.wSD) for substructure segmentation for MRgRT.
METHODS AND MATERIALS: Eighteen (institute A) patients who underwent thoracic or abdominal radiation therapy on a 0.35 T MR-guided linear accelerator were retrospectively evaluated. On each image, 1 of 2 radiation oncologists delineated reference contours of 12 cardiac substructures (chambers, great vessels, and coronary arteries) used to train (n = 10), validate (n = 3), and test (n = 5) nnU-Net.wSD by leveraging a teacher-student network and comparing it to standard 3-dimensional U-Net. The impact of using simulation data or including 3 to 4 daily images for augmentation during training was evaluated for nnU-Net.wSD. Geometric metrics (Dice similarity coefficient, mean distance to agreement, and 95% Hausdorff distance), visual inspection, and clinical dose-volume histograms were evaluated. To determine generalizability, institute A's model was tested on an unlabeled data set from institute B (n = 22) and evaluated via consensus scoring and volume comparisons.
RESULTS: nnU-Net.wSD yielded a Dice similarity coefficient (reported mean ± SD) of 0.65 ± 0.25 across the 12 substructures (chambers, 0.85 ± 0.05; great vessels, 0.67 ± 0.19; and coronary arteries, 0.33 ± 0.16; mean distance to agreement, <3 >mm; mean 95% Hausdorff distance, <9 >mm) while outperforming the 3-dimensional U-Net (0.583 ± 0.28; P.05) for 11 of 12 substructures, with larger volumes requiring minor changes and coronary arteries exhibiting more variability.
CONCLUSIONS: This work is a critical step toward rapid and reliable cardiac substructure segmentation to improve cardiac sparing in low-field MRgRT.
Medical Subject Headings
Humans; Deep Learning; Radiotherapy, Image-Guided; Heart; Retrospective Studies; Magnetic Resonance Imaging; Organs at Risk; Abdominal Neoplasms; Male; Radiotherapy Planning, Computer-Assisted; Radiotherapy Dosage; Thoracic Neoplasms
PubMed ID
38797498
ePublication
ePub ahead of print
Volume
120
Issue
3
First Page
904
Last Page
914