Evaluation of a Combined Reflectance Confocal Microscopy–Optical Coherence Tomography Device for Detection and Depth Assessment of Basal Cell Carcinoma

Abstract

IMPORTANCE The limited tissue sampling of a biopsy can lead to an incomplete assessment of basal cell carcinoma (BCC) subtypes and depth. Reflectance confocal microscopy (RCM) combined with optical coherence tomography (OCT) imaging may enable real-time, noninvasive, comprehensive three-dimensional sampling in vivo, which may improve the diagnostic accuracy and margin assessment of BCCs.OBJECTIVE To determine the accuracy of a combined RCM-OCT device for BCC detection and deep margin assessment. DESIGN, SETTING, AND PARTICIPANTSThis pilot study was carried out on 85 lesions from 55 patients referred for physician consultation or Mohs surgery at Memorial Sloan Kettering Skin Cancer Center in Hauppauge, New York. These patients were prospectively and consecutively enrolled in the study between January 1, 2017, and December 31, 2017. Patients underwent imaging, with the combined RCM-OCT probe, for previously biopsied, histopathologically confirmed BCCs and lesions clinically or dermoscopically suggestive of BCC. Only patients with available histopathologic examination after imaging were included. MAIN OUTCOMES AND MEASURESImprovements in sensitivity, specificity, and diagnostic accuracy for BCC using the combined RCM-OCT probe as well as the correlation between OCT-estimated depth and histopathologically measured depth were investigated. RESULTSIn total, 85 lesions from 55 patients (27 [49%] were female and 28 [51%] were male with a median [range] age of 59 [21-90] years) were imaged. Imaging was performed on 25 previously biopsied and histopathologically confirmed BCCs and 60 previously nonbiopsied but clinically or dermoscopically suspicious lesions. Normal skin and BCC features were correlated and validated with histopathologic examination. In previously biopsied lesions, residual tumors were detected in 12 of 25 (48%) lesions with 100% sensitivity (95% CI, 73.5%-100%) and 23.1% specificity (95% CI, 5.0%-53.8%) for combined RCM-OCT probe. In previously nonbiopsied and suspicious lesions, BCCs were diagnosed in 48 of 60 (80%) lesions with 100% sensitivity (95% CI, 92.6%-100%) and 75% specificity (95% CI, 42.8%-94.5%). Correlation was observed between depth estimated with OCT and depth measured with histopathologic examination: the coefficient of determination (R 2 ) was 0.75 (R = 0.86; P < .001) for all lesions, 0.73 (R = 0.85; P < .001) for lesions less than 500 μm deep, and 0.65 (R = 0.43; P < .001) for lesions greater than 500 μm deep. CONCLUSIONS AND RELEVANCECombined RCM-OCT imaging may be prospectively used to comprehensively diagnose lesions suggestive of BCC and triage for treatment. Further validation of this device must be performed on a larger cohort.

Peri‐operative delineation of non‐melanoma skin cancer margins in vivo with handheld reflectance confocal microscopy and video‐mosaicking

“…Other approaches towards quicker detection of margins may be to synergistically combine RCM video‐mosaicking with either a faster but lower‐resolution approach such as OCT, or faster but widefield approaches such as multimodal polarization‐enhanced reflectance and fluorescence imaging (PERFI) and optical polarization imaging (OPI) . The ability of OCT imaging to quickly delineate normal skin, and then guide RCM imaging towards detection of BCCs in the remaining suspicious areas was recently reported . Similarly, PERFI or OPI may delineate unequivocally normal or positive areas and then guide RCM imaging towards detection in the remaining suspicious areas.…”

Basal cell carcinoma treated with combined ablative fractional laser and ingenol mebutate – an exploratory study monitored by optical coherence tomography and reflectance confocal microscopy

“…Thus, OCT and RCM technologies may complement one another to detect BCCs . OCT and RCM have been applied, mostly individually, to monitor topical and surgical treatments of BCC and could be valuable tools to monitor AFL‐assisted IM treatment of BCCs …”

The road to real‐time, bedside, optical imaging pathology: basal cell carcinoma and beyond

“…However, technology can lend a hand – confocal microscopy (CM) is a noninvasive optical imaging device that uses a low‐intensity laser to generate quasi‐histological images. Typically, CM is used in vivo for the diagnosis and management of skin neoplasms in its reflectance mode (RCM) or in association with optical coherence tomography, with excellent diagnostic accuracy for the diagnosis of BCC and other skin malignancies . However, CM can also be used ex vivo in excised tissue using fluorescence (FCM) mode .…”

“…Based on early developments in optical imaging technology driven by the visions of clinicians and their needs in clinical settings and with continuous evolving ideas, dermatologists and engineers are working side by side to overcome numerous challenges for a much more user‐friendly and sustainable technology . Key developments of the CM technology such as strip mosaicking, multimodal imaging and digital staining have brought ex vivo CM into a new era that is not far from the reality of real‐time at‐the‐bedside pathology . With the continuous development of optical systems for imaging deeper into the tissue with a better signal‐to‐noise ratio, computational sciences and artificial intelligence for image enhancement and automated analysis, and new contrast agents for specific tissue detection, we will eventually achieve the noninvasive, optical imaging pathology of the future, for BCC and beyond.…”

“…Typically, CM is used in vivo for the diagnosis and management of skin neoplasms in its reflectance mode (RCM) or in association with optical coherence tomography, with excellent diagnostic accuracy for the diagnosis of BCC and other skin malignancies. [4][5][6][7] However, CM can also be used ex vivo in excised tissue using fluorescence (FCM) mode. 5,8 The main advantage of FCM includes the addition of fluorescent stains (e.g.…”