Abstract: |
Radiotherapy doses to some cardio-pulmonary substructures may be critical factors in the observed early mortality following radiotherapy for nonsmall cell lung cancer patients. Our goal is to provide an open-source tool to automatically segment cardio-vascular substructures for consistent outcomes analyses, and subsequently for radiation treatment planning of thoracic patients. Here, we built and validated a multi-label Deep Learning Segmentation (DLS) framework for accurate auto-segmentation of cardio-pulmonary substructures. The DLS framework utilized a deep neural network architecture to segment 12 cardio-pulmonary substructures from Computed Tomography (CT) scans of 217 patients previously treated with thoracic RT. The model was robust against variability in image quality characteristics, including the presence/absence of contrast. A hold-out dataset of additional 24 CT scans was used for quantitative evaluation of the final model against expert contours using Dice Similarity Coefficients (DSC) and 95th Percentile of Hausdorff Distance (HD95). DLS contours of an additional 10 CT scans were reviewed by a radiation oncologist to determine the number of slices in need of adjustment for each of the non-overlapping substructures. The DLS model reduced segmentation time per patient from about one hour of manual segmentation to 10 s. Quantitatively, the highest accuracy was observed for the Heart (median DSC = (0.96(0.91 - 0.93 )) and HD95 = (4.3 mm(3.8 mm − 5.5 mm)). The median DSC for the remaining structures was 0.80 - 0.92. The expert judged that, on average, 85% of the contours were equivalent to state-of-the-art manual contouring and did not require any modifications. © Springer Nature Switzerland AG 2019. |