Feasibility of white light scan technology for monitoring response to vacuum bell therapy in pectus excavatum.

BACKGROUND

The Haller Index (HI), derived from radiographic imaging, is the standard for measuring severity of pectus excavatum (PE). To better mirror radiography without repeated radiation exposure, we sought to assess the reliability of a handheld 3D White Light (WL) Scanner to evaluate response to vacuum bell (VB) treatment and compare WL scan-derived indices to the conventional radiographic HI and manual funnel depth (FD).

STUDY

DESIGN

A retrospective review was performed from 2022 to 2025 of PE patients who had a WL scan performed before initiating therapy and at subsequent clinic visits after starting VB therapy. Two measurements were derived from the scan: 1) a WL scan - derived "external" Haller index (WLS_HI) and 2) a novel WL scan - derived maximal FD (WLS_FD). Additionally, FD which was manually measured by the provider. Paired t-tests and Pearson's correlation were used for analysis.

RESULTS

Fifty patients had a median time to last follow-up of 9 months. There was a significant mean decrease of 3.5 ± 8.8 mm (P < 0.05), or an average of 15 % in FD. This corresponded to a significant mean decrease of 3.2 ± 4.5 mm (P < 0.05) or an average of 16 % in WLS_FD. WLS_FD correlated strongly with FD (r = 0.86, P < 0.05) and weakly with HI (r = 0.36, P < 0.05). WLS_HI had the strongest correlation with HI (r = 0.52, P < 0.05).

CONCLUSIONS

WL scan measurements reliably showed an improvement in WLS_FD during the use of VB therapy and is a feasible way of objectively quantifying the severity of PE deformities and reliably monitoring defect progression in response to VB therapy.