Diagnosis of basal cell carcinoma in the head and neck by dermoscopy and handheld reflectance confocal microscopy.

The increasing incidence of basal cell carcinoma (BCC) in the Netherlands has become a burden on healthcare system due to the associated costs in diagnosing, treatment, and follow-up of BCC patients. As the majority of BCCs requiring surgical treatment are localized in the head and neck, accurate presurgical subtyping is essential.The use of dermoscopy has been shown to significantly increase the accuracy of diagnosing BCCs, nevertheless, punch biopsy remains the reference standard due to the limited accuracy of BCC subtyping purely based on the clinical diagnosis. Even so, there is a substantial discordance between biopsy and excisional specimens where in 15% of the cases a more aggressive BCC subtype is found following excision. Reflectance confocal microscopy (RCM) is a noninvasive imaging technique that allows the in vivo visualization of cutaneous structures at a cellular-level, with an estimated sensitivity and specificity of 97% and 93% respectfully in diagnosing BCC. A handheld-RCM (HH-RCM) device (VivaScope®3000; CaliberID) was introduced allowing for more rapid evaluation and accessibility to the more concave areas in the head and neck (i.e. nose, periorbital and ears), while retaining comparable accuracy compared to conventional RCM. Several criteria were described positively correlating with the diagnosis of BCCs, however few studies have described criteria to differentiate between the different BCC subtypes. Our primary objectives are to: (1) To determine the diagnostic value of the addition of HH-RCM to dermoscopy in the management of BCC in the head and neck, defined by an significant increase in diagnostic accuracy in the diagnosing/subtyping of BCC. (2) Compare the diagnostic accuracy of dermoscopy and HH-RCM to the current diagnostic reference standard (punch biopsy).

Our primary objectives are to determine the diagnostic accuracy of handheld RCM in the diagnosing and subtyping of BCC in the head and neck compared to punch biopsy, and evaluate the associated rate of over- and understaging of BCC subtypes. In addition, we will evaluate the reliability of naked-eye examination and the diagnostic significance of established dermoscopic and RCM criteria in the differentiation of BCC subtypes in the head and neck

This study was designed as a single-center, prospective, paired cross-sectional cohort study, conducted at the Netherlands Cancer Institute (NKI) (Amsterdam).

Reflection confocal microscopy

"Participating subjects will not receive any clinical relevant delay in treatment or miss out of any standard of care and follow-up. There will be no additional visits to the outpatient clinic of Dermatology of the NKI compared to regular standard of care as study assessment will take place during the standard follow-up visits. Local side effects of routine invasive procedures in this study (punch biopsy and surgical excision) include erythema (often 1-2 weeks), pain (common 1 day), local swelling (often 1-3 days), abnormal scar formation (rare), hypo- and or hyperpigmentation (rare) and wound infection (rare). The RCM diagnostic procedure is non-invasive, painless and no side effects have been reported. There are no associated systemic side effects with any of the involved procedures. The burden due to study requirements is minimal. The RCM imaging will not interfere with the standard of care. "