A Novel Objective Approach to the External Measurement of Pectus Excavatum Severity By Means of an Optical Device

Background Current approaches to quantifying the severity of pectus excavatum (PE) require internal measurements based on cross-sectional imaging. The aim of this study is to exploit a novel index evaluated on the external surface of the chest with a 3D optical scanner. Methods 51 children (41 males, 10 females), between 2 and 17 years old, were evaluated with a 3D optical scanner. PE severity was calculated by using an ad hoc instant 3D scanner and defining an automatic procedure to generate an optical 3D index (CI-3D). For the latter, an ideal threshold was derived from a statistical analysis and five blind surveys were collected from pediatric specialists on chest wall deformities. CI-3D was then correlated with blind clinical assessments of PE severity. Results The cut-off thresholds were determined to optimally discriminate between six degrees of severity of pectus patients by a correlation analysis. The correlation coefficient obtained by matching CI-3D with the average subjective severity shows that the proposed method outperforms traditional approaches. Conclusions CI-3D has a good match with the average subjective assessment in distinguishing patients with mild to severe PE. This innovative approach offers several advantages over existing indices, as it is repeatable and does not require cross-sectional imaging. The index might be particularly suitable for monitoring the efficacy of non-operative treatment and, in the future, for designing an optimal personalized usage of therapeutic devices.