Author/Authors :
Weikert, Thomas Department of Radiology - University Hospital Basel - University of Basel - Petersgraben - Basel, Switzerland , D’Antonoli, Tugba Akinci Department of Radiology - University Hospital Basel - University of Basel - Petersgraben - Basel, Switzerland , Bremerich, Jens Department of Radiology - University Hospital Basel - University of Basel - Petersgraben - Basel, Switzerland , Stieltjes, Bram Department of Radiology - University Hospital Basel - University of Basel - Petersgraben - Basel, Switzerland , Sommer, Gregor Department of Radiology - University Hospital Basel - University of Basel - Petersgraben - Basel, Switzerland , Sauter, Alexander W Department of Radiology - University Hospital Basel - University of Basel - Petersgraben - Basel, Switzerland
Abstract :
Automated detection and segmentation is a prerequisite for the deployment of image-based secondary analyses, especially for lung
tumors. However, currently only applications for lung nodules ≤3 cm exist. Therefore, we tested the performance of a fully
automated AI-based lung nodule algorithm for detection and 3D segmentation of primary lung tumors in the context of tumor
staging using the CT component of FDG-PET/CT and including all T-categories (T1–T4). FDG-PET/CTs of 320 patients with
histologically conrmed lung cancer performed between 01/2010 and 06/2016 were selected. First, the main primary lung tumor
within each scan was manually segmented using the CT component of the PET/CTs as reference. Second, the CT series were
transferred to a platform with AI-based algorithms trained on chest CTs for detection and segmentation of lung nodules.
Detection and segmentation performance were analyzed. Factors inuencing detection rates were explored with binominal
logistic regression and radiomic analysis. We also processed 94 PET/CTs negative for pulmonary nodules to investigate frequency
and reasons of false-positive ndings. The ratio of detected tumors was best in the T1-category (90.4%) and decreased continuously: T2 (70.8%), T3 (29.4%), and T4 (8.8%). Tumor contact with the pleura was a strong predictor of misdetection.
Segmentation performance was excellent for T1 tumors (r = 0.908, p < 0.001) and tumors without pleural contact (r = 0.971,
p < 0.001). Volumes of larger tumors were systematically underestimated. There were 0.41 false-positive ndings per exam. The
algorithm tested facilitates a reliable detection and 3D segmentation of T1/T2 lung tumors on FDG-PET/CTs. The detection and
segmentation of more advanced lung tumors is currently imprecise due to the conception of the algorithm for lung nodules <3 cm.
Future efforts should therefore focus on this collective to facilitate segmentation of all tumor types and sizes to bridge the gap
between CAD applications for screening and staging of lung cancer.
