# Systematic Review of Line-Field Confocal Optical Coherence Tomography for Diagnosing Pre-Malignant and Malignant Keratinocytic Lesions: Optimising the Workflow

## TL;DR

This systematic review evaluates how line-field confocal optical coherence tomography can be used to diagnose skin lesions and suggests ways to improve its workflow and standardization.

## Contribution

The study provides a framework for standardizing LC-OCT protocols and highlights multimodal imaging techniques to enhance diagnostic accuracy.

## Key findings

- LC-OCT reliably identifies histopathological features like hyperkeratosis and keratinocytic atypia.
- Multimodal imaging and technical optimizations improve image resolution and interobserver agreement.
- LC-OCT can detect invasive features such as disruptions in the dermo-epidermal junction.

## Abstract

Background: Line-field confocal optical coherence tomography (LC-OCT) is a non-invasive imaging technique providing high-resolution en-face and cross-sectional views of the epidermis and superficial dermis for in vivo characterisation of actinic keratosis (AK), Bowen’s disease (BD) and squamous cell carcinoma (SCC). Despite its promise, standardised imaging protocols are lacking. Objective: This systematic review aims to assess the utility of LC-OCT for diagnosing AK, BD and SCC, with particular emphasis on workflow optimisation and protocol standardisation. Methods: A systematic literature search was performed using PubMed, Embase, and Scopus databases (January 2018–October 2024). Two reviewers independently screened the records, extracted data and applied the Confidence in the Evidence from Reviews of Qualitative research (CERQual) framework to assess confidence in key findings. Results: Eleven studies met the inclusion criteria. LC-OCT reliably identified key histopathological correlates. Across studies, LC-OCT consistently visualised hyperkeratosis, keratinocytic atypia, parakeratosis, and acanthosis, as well as characteristic vascular alterations and dermal remodeling. LC-OCT also demonstrated its capacity to detect invasive features by revealing disruptions in the dermo-epidermal junction and the presence of tumour strands infiltrating the dermis. Multimodal imaging combined with technical optimisations such as minimal probe pressure, paraffin oil coupling, and dermoscopy-guided localisation, substantially improved image resolution and interobserver concordance. Conclusions: This systematic review provides a basis for establishing standardised LC-OCT imaging protocols in keratinocytic tumours. While LC-OCT shows promise as a non-invasive diagnostic tool, further multicenter studies are needed to refine imaging workflows and evaluate the integration of artificial intelligence-based analysis to improve diagnostic accuracy and reproducibility.