Line-Field Confocal Optical Coherence Tomography May Enhance Monitoring of Superficial Basal Cell Carcinoma Treated with Imiquimod 5% Cream: A Pilot Study

SIMPLE SUMMARY: Line-field confocal optical coherence tomography (LC-OCT) is a new non-invasive technique that allows the visualization of the epidermis and dermis and their different structures and findings at the cellular level, providing a sort of “virtual biopsy”. The interest of using LC-OCT in the diagnosis of skin disorders is growing. The purpose of this study was to investigate if LC-OCT may be useful to enhance the monitoring of superficial basal cell carcinoma (BCC) in a series of patients treated with IQ 5% cream, an immune response modifier currently approved in Europe and the USA. In our experience, LC-OCT was able to show sub-clinical signs of BCC after treatment, leading to a further cycle of IQ 5% cream. Based on our preliminary results, LC-OCT may represent a promising tool able to enhance the evaluation of the treatment response of BCCs to non-surgical treatments. ABSTRACT: Line-field confocal optical coherence tomography (LC-OCT) is a novel, non-invasive technique for real-time skin imaging. Imiquimod (IQ) 5% cream is an immune response modifier currently approved for the treatment of small, superficial basal cell carcinoma (BCC). The aim of this study was to investigate if LC-OCT may be useful to enhance the treatment monitoring of BCC. Twenty superficial BCCs from 12 patients were treated with IQ 5% cream once daily, five days a week, for six weeks. Clinical and LC-OCT evaluations were performed at baseline and 4 weeks after the end of treatment. At the end of the study, 13 lesions showed a complete clinical and LC-OCT response, 4 lesions a partial clinical and LC-OCT response, and 3 lesions a complete clinical response but residual tumoral signs at LC-OCT. Our pilot study suggests that LC-OCT may represent a promising tool able to enhance the evaluation of the treatment response of BCCs to non-invasive treatments. In our case series, its use highlighted, through a detailed, fast, and complete examination of the treated area, three cases of residual BCC that otherwise would have gone undetected at clinical examination. Future studies on larger series of patients treated with different modalities and with a longer follow-up are advisable.