Influence of CT dose reduction on AI-driven malignancy estimation of incidental pulmonary nodules

Objectives The purpose of this study was to determine the influence of dose reduction on a commercially available lung cancer prediction convolutional neuronal network (LCP-CNN).Methods CT scans from a cohort provided by the local lung cancer center (n = 218) with confirmed pulmonary malignancies and their corresponding reduced dose simulations (25% and 5% dose) were subjected to the LCP-CNN. The resulting LCP scores (scale 1-10, increasing malignancy risk) and the proportion of correctly classified nodules were compared. The cohort was divided into a low-, medium-, and high-risk group based on the respective LCP scores; shifts between the groups were studied to evaluate the potential impact on nodule management. Two different malignancy risk score thresholds were analyzed: a higher threshold of >= 9 (rule-in approach) and a lower threshold of > 4 (rule-out approach).Results In total, 169 patients with 196 nodules could be included (mean age +/- SD, 64.5 +/- 9.2 year; 49% females). Mean LCP scores for original, 25% and 5% dose levels were 8.5 +/- 1.7, 8.4 +/- 1.7 (p > 0.05 vs. original dose) and 8.2 +/- 1.9 (p < 0.05 vs. original dose), respectively. The proportion of correctly classified nodules with the rule-in approach decreased with simulated dose reduction from 58.2 to 56.1% (p = 0.34) and to 52.0% for the respective dose levels (p = 0.01). For the rule-out approach the respective values were 95.9%, 96.4%, and 94.4% (p = 0.12). When reducing the original dose to 25%/5%, eight/twenty-two nodules shifted to a lower, five/seven nodules to a higher malignancy risk group.Conclusion CT dose reduction may affect the analyzed LCP-CNN regarding the classification of pulmonary malignancies and potentially alter pulmonary nodule management.

Automated summary

This study aimed to determine the influence of dose reduction on a commercially available lung cancer prediction convolutional neuronal network (LCP-CNN). The results showed that CT dose reduction may affect the classification of pulmonary malignancies and potentially alter pulmonary nodule management.