Handheld optical coherence tomography–reflectance confocal microscopy probe for detection of basal cell carcinoma and delineation of margins

Abstract

We present a hand-held implementation and preliminary evaluation of a combined optical coherence tomography (OCT) and reflectance confocal microscopy (RCM) probe for detecting and delineating the margins of basal cell carcinomas (BCCs) in human skin <italic<in vivo</italic<. A standard OCT approach (spectrometer-based) with a central wavelength of 1310 nm and 0.11 numerical aperture (NA) was combined with a standard RCM approach (830-nm wavelength and 0.9 NA) into a common path hand-held probe. Cross-sectional OCT images and enface RCM images are simultaneously displayed, allowing for three-dimensional microscopic assessment of tumor morphology in real time. Depending on the subtype and depth of the BCC tumor and surrounding skin conditions, OCT and RCM imaging are able to complement each other, the strengths of each helping overcome the limitations of the other. Four representative cases are summarized, out of the 15 investigated in a preliminary pilot study, demonstrating how OCT and RCM imaging may be synergistically combined to more accurately detect BCCs and more completely delineate margins. Our preliminary results highlight the potential benefits of combining the two technologies within a single probe to potentially guide diagnosis as well as treatment of BCCs.

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

“…RCM-OCT imaging was performed using the hand-held probe, the technical details for which are previously described. 25 RCM imaging is with a lateral resolution of ~1 µm, optical sectioning of ~3 µm, with en face field of view (FOV) of 750×750 µm. OCT imaging is with lateral resolution of ~5 µm, axial resolution of 10 µm, and orthogonal FOV of 1000 µm deep × 2000 µm wide.…”

“…We placed adhesive paper rings (3M, Flemington, NJ) at the clinical margins for image navigation; this is a previously proven method. 25,26 Dermoscopic examination was subsequently carried out with a handheld dermatoscope within the paper ring. The ring divided the lesion in four hypothetical quadrants; the imaging in dermoscopically-suspicious areas was guided through these quadrants and clock positions.…”

“…25 Here, we report a clinical study on testing the handheld probe on patients. Two types of lesions were imaged: (1) previously-biopsied, histopathologically-proven BCCs and (2) previously non-biopsied, clinically/dermoscopically suspicious for BCCs.…”

Label-free optical imaging technologies for rapid translation and use during intraoperative surgical and tumor margin assessment

“…Optical coherence tomography (OCT) has been demonstrated for imaging the in vivo tumor resection bed in human subjects during breast cancer surgery, yielding a sensitivity and specificity of 91.7% and 92.1%, respectively, for detecting positive margins (Fig. 1), 52 as well as for imaging the surgical margins of resected tumor specimens 19,20,[53][54][55] and loco-regional lymph nodes in human breast cancer surgeries. 56 Related to OCT, optical coherence elastography provides 3-D maps of tissue mechanical properties, on the micrometer to millimeter scale.…”

“…Accurate identification of varying types of breast malignancies was demonstrated, and the study was enhanced by clinically relevant data analysis in which entire images were reviewed (rather than a selection of smaller ROIs) and compared to standard histology. Iftimia et al 19 demonstrated the possibility of combining OCT as a fast, low-resolution technique for screening for suspicious areas in large specimens with confocal microscopy, a slower but higher resolution technique for detailed analysis of suspicious areas. This is an attractive strategy that can seamlessly integrate the technical advantages of multiple techniques while minimizing the practical limitations of each.…”