Basal cell carcinoma (BCC) is the most common skin cancer in the Netherlands, with incidence rates continuing to rise. The current diagnostic standard combines clinical evaluation and dermoscopy, while biopsy followed by histopathological examination remains the gold standard when uncertainty about the diagnosis persists. However, biopsy is invasive, time-consuming, and costly. Line-field confocal optical coherence tomography (LC-OCT) is a non-invasive imaging technique that has emerged as a promising alternative to biopsy for BCC suspected lesions.

This retrospective study aims to evaluate the real-world clinical performance of LC-OCT in routine dermatological practice, where it has been integrated into the diagnostic work-up for BCC-suspect lesions.

Basal cell carcinoma (BCC) is the most common type of skin cancer in the Netherlands, with its incidence having increased substantially in recent years. ). Over the past decades, non-invasive imaging techniques such as line-field confocal optical coherence tomography (LC-OCT) have emerged as promising alternatives to biopsy for the diagnosis of BCC. When BCC can be diagnosed with high confidence using (LC-)OCT, this may reduce the need for biopsies, accelerate treatment initiation, and improve healthcare efficiency. LC-OCT combines the principles of conventional optical coherence tomography (OCT) and reflectance confocal microscopy (RCM), enabling three-dimensional visualization of the skin at a cellular resolution.

Several studies have reported a high specificity of LC-OCT for identifying non-BCC lesions, ranging from 97-99%. In cases where BCC can be diagnosed with high confidence, biopsy may theoretically be omitted, meaning that treatment could be initiated promptly. Reported sensitivities for such "high-confidence" BCC diagnoses range from 95-100%.

Although the diagnostic accuracy of LC-OCT has been investigated extensively in research settings, evidence on its real-world clinical performance remains limited. This retrospective study aims to evaluate the clinical utility of LC-OCT in routine dermatological practice.

Inclusion Criteria:

• Patients aged ≥18 years
• LC-OCT performed as part of diagnostic evaluation between January 2025 and June 2025 at Mohs clinics in the Netherlands
• Histopathological results (biopsy or excision) and/or 6-12 month clinical follow-up data available

Exclusion Criteria:

• Patients <18 years of age
• Cases without histopathological confirmation or available follow-up data

Patients with lesions clinically suspected for BCC who visited the Mohs Clinics between January 2025 and June 2025 and underwent LC-OCT imaging as part of the diagnostic work-up.

IPD may be shared with other researchers upon reasonable request. Requests will be evaluated on a case by case manner.