Smartphone-Based 3D Surface Imaging for Breast Anthropometry, Symmetry Assessment, and Volumetry: A Structured...

Background: Objective breast assessment is relevant in aesthetic, reconstructive, and oncoplastic breast surgery. Smartphones and tablets are widely available devices that may offer an accessible means for three-dimensional (3D) breast surface imaging, with potential relevance for preoperative assessment, surgical planning, and outcome evaluation. However, the available evidence is heterogeneous, and the validity of different devices, applications, and workflows remains unclear. This narrative review aimed to summarize the evidence on smartphone-based 3D surface imaging. Methods: A structured literature search was conducted in PubMed, Embase, Web of Science, and EBSCOhost. Only original studies that used smartphone- or tablet-based breast assessment were included. Data extraction included devices, software, population/material, outcomes, comparators, validation metrics, and limitations. Reporting completeness was assessed using an adapted GRRAS-based appraisal. Results: A total of 9 studies representing approximately 7 independent datasets were included. Only two studies assessed volumetry as one of the primary aims. The evidence base was small and heterogeneous. Most studies were patient-based, while the remaining studies used phantom or model-based designs. Feasibility was demonstrated for selected device-application-workflow combinations, predominantly involving iPhones and the 3D Scanner App, but these findings were not generalizable to smartphone-based 3D breast imaging as a whole. Evidence was more favorable for selected linear anthropometric measurements than for volumetry. Key limitations included breast ptosis, inframammary fold (IMF) geometry, posterior boundary definition, software, and operator dependence. Three of the included reports had potentially overlapping cohorts. Due to substantial heterogeneity in devices, applications, comparators, outcomes, and validation metrics, meta-analysis was not performed. Conclusions: Current evidence is limited to a small number of heterogeneous, predominantly single-center datasets and supports only workflow-specific feasibility for selected anthropometric and surface-based measurements. These findings should not be generalized across smartphone devices, applications, or reconstruction workflows. Breast volumetry remains insufficiently validated and is supported by only two non-comparable studies. Future studies should provide more detailed reporting that focuses on objective characteristics of the workflow and outcomes, including predefined analyses of agreement and measurement error.