Evaluating the performance of a deep learning-based computer-aided diagnosis (DL-CAD) system for detecting and characterizing lung nodules: Comparison with the performance of double reading by radiologists

Background The study was conducted to evaluate the performance of a state-of-the-art commercial deep learning-based computer-aided diagnosis (DL-CAD) system for detecting and characterizing pulmonary nodules. Methods Pulmonary nodules in 346 healthy subjects (male: female = 221:125, mean age 51 years) from a lung cancer screening program conducted from March to November 2017 were screened using a DL-CAD system and double reading independently, and their performance in nodule detection and characterization were evaluated. An expert panel combined the results of the DL-CAD system and double reading as the reference standard. Results The DL-CAD system showed a higher detection rate than double reading, regardless of nodule size (86.2% vs. 79.2%; P < 0.001): nodules >= 5 mm (96.5% vs. 88.0%; P = 0.008); nodules < 5 mm (84.3% vs. 77.5%; P < 0.001). However, the false positive rate (per computed tomography scan) of the DL-CAD system (1.53, 529/346) was considerably higher than that of double reading (0.13, 44/346; P < 0.001). Regarding nodule characterization, the sensitivity and specificity of the DL-CAD system for distinguishing solid nodules > 5 mm (90.3% and 100.0%, respectively) and ground-glass nodules (100.0% and 96.1%, respectively) were close to that of double reading, but dropped to 55.5% and 93%, respectively, when discriminating part solid nodules. Conclusion Our DL-CAD system detected significantly more nodules than double reading. In the future, false positive findings should be further reduced and characterization accuracy improved.