Skin lesion triage in organ transplant recipients using line-field confocal optical coherence tomography: a retrospective classification study

Background/objectives: Organ transplant recipients (OTRs) face an elevated risk of keratinocyte carcinomas (KC), leading to a lower threshold for biopsy. Line-field confocal optical coherence tomography (LC-OCT) is a non-invasive imaging technique capable of visualizing malignant skin changes, yet its role in the management of OTRs remains unexplored. The objective was to investigate the potential of LC-OCT for triage of skin lesions in OTRs. Patients and methods: Clinically equivocal lesions in OTRs (n = 75) were scanned using LC-OCT before biopsy. Scans were assessed retrospectively for predefined LC-OCT criteria (i.e., image-markers) for KC and premalignant/in-situ lesions (Bowen's disease and actinic keratosis). The most high-yield criteria were identified and combined into a decision-tree. Results: A 4-step decision-tree for lesion triage with five LC-OCT criteria was developed, with a sensitivity of 87.5 % for squamous cell carcinoma (n = 8), 94.4 % for basal cell carcinoma (n = 18), 83.3 % for Bowen's disease (n = 12), and 72.7 % for actinic keratosis (n = 22). This triage is based on severe dysplasia, broad strands and keratin pearls for SCC, lobules for BCC, and severe or mild-moderate dysplasia for premalignant lesions. Conclusions: This study designed an LC-OCT decision-tree for use in immunocompromised patients to assist in triage of equivocal skin lesions with potential for improving clinical-decision making.