Differentiation of Basal Cell Carcinoma Subtypes in Multi-Beam Swept Source Optical Coherence Tomography (MSS-OCT).

BACKGROUND: Optical coherence tomography (OCT) is a technique that enables real-time in-vivo examination of tissue. This technology provides the clinician with the potential to use a non-invasive tool in the identification and diagnosis of many skin lesions. However, the diagnostic features of basal cell carcinoma have not yet been described with comparison to their histopathology.
OBJECTIVES: To identify and describe key features of basal cell carcinoma (BCC) and its subtypes as they present in multi-beam Swept Source - OCT (MSS-OCT), and to correlate those against conventional histopathology.
METHODS: A total of 40 lesions were assessed by MSS-OCT prior to biopsy. 60-slice OCT images of the lesions were obtained and correlated with histology sections taken in the same plane. OCT scans were assessed retrospectively by a panel to determine the OCT criteria for BCC and its subtypes.
RESULTS: The following diagnostic criteria were identified: hyporeflective ovoid structures (40/40), dark halo boundaries (38/40), epidermal thinning (28/40), and collagen compression (14/40). Lesional tissue also showed a destruction of layers when compared to the surrounding normal tissue. In addition to the shared criteria, other subtypes showed distinct diagnostic criteria.
CONCLUSION: With its higher sensitivity, using MSS-OCT allowed for non-invasive, accurate identification of the key diagnostic features of BCC and its subtypes with high correlation to the histopathologic features found with biopsy.

J Drugs Dermatol. 2016;15(5):545-550.

Optical coherence tomography imaging of erythematotelangiectatic rosacea during treatment with brimonidine topical gel 0.33%: a potential method for treatment outcome assessment.

BACKGROUND: Patients with moderate to severe rosacea often seek treatment to reduce erythema and vascular markings. Few studies have looked at the effectiveness of the novel treatment, brimonidine topical gel 0.33%, trademark name Mirvaso®, in the treatment of rosacea. We report the use of optical coherence tomography (OCT) scanning to monitor the effectiveness of Mirvaso® on in vivo skin. OCT is a non-invasive optical imaging technique that can provide high-resolution imaging of vessel and cellular morphology. OCT may be useful as a pre-treatment assessment tool for identifying possible morphologic features in the skin that may serve as outcome predictors. OCT may also serve as a monitoring tool in the treatment of rosacea. OBJECTIVE: To examine and describe how OCT skin morphology changes when exposed to brimonidine topical gel 0.33% in the treatment of erythematotelangiectatic rosacea. METHODS: Normal in vivo telangiectasias and erythematous patches and papules were examined prior to treatment clinically, dermatoscopically, and through OCT scans. Brimonidine topical gel 0.33% was applied to the face and OCT images were acquired at defined time intervals: baseline; immediately (<5 minutes) after application; 4 hours after application; and after 2 weeks' once daily application. OCT morphology was then described. RESULTS: OCT imaging showed an increase in the mean gray value (MGV), a measure of dermal reflectivity, corresponding to a decrease in dermal edema. MGV measurements for the nasal telangiectasia were: baseline, MGV 10,471 (standard deviation [SD] 6,847); immediate, MGV 15,634 (SD 8,983); after 4 hours, MGV 16,357 (SD 7,647); and after 2 weeks, MGV 15,505 (SD 6,870). MGV measurements for the chin erythema were: baseline, MGV 8,850 (SD 4,969); immediate, MGV 10,799 (SD 5,266); after 4 hours, MGV 12,419 (SD 6,714); and after 2 weeks, MGV 13,395 (SD 6,170). No significant change in vessel lumen diameter was appreciated. Vessel lumen diameter for the facial papule ranged from 0.13 mm at baseline, 0.09 mm immediately after treatment, 0.09 mm after 4 hours, and 0.11 mm after 2 weeks. CONCLUSIONS: OCT scanning showed a decrease in the dermal hyporeflectivity of the dermis consistent with a decrease in dermal edema. The OCT scans obtained did not show any significant change in vessel lumen diameter. These results may reflect an increase in vascular tone, which can be attributable to the clinical improvement and decreased erythema noted in the patient. This technology could potentially be used for the non-invasive in vivo monitoring of other topical treatments.

Virtual skin biopsy by optical coherence tomography: the first quantitative imaging biomarker for scleroderma.

BACKGROUND: Skin involvement is of major prognostic value in systemic sclerosis (SSc) and often the primary outcome in clinical trials. Nevertheless, an objective, validated biomarker of skin fibrosis is lacking. Optical coherence tomography (OCT) is an imaging technology providing high-contrast images with 4 µm resolution, comparable with microscopy ('virtual biopsy'). The present study evaluated OCT to detect and quantify skin fibrosis in SSc. METHODS: We performed 458 OCT scans of hands and forearms on 21 SSc patients and 22 healthy controls. We compared the findings with histology from three skin biopsies and by correlation with clinical assessment of the skin. We calculated the optical density (OD) of the OCT images employing Matlab software and performed statistical analysis of the results, including intraobserver/interobserver reliability, employing SPSS software. RESULTS: Comparison of OCT images with skin histology indicated a progressive loss of visualisation of the dermal-epidermal junction associated with dermal fibrosis. Furthermore, SSc affected skin showed a consistent decrease of OD in the papillary dermis, progressively worse in patients with worse modified Rodnan skin score (p<0.0001). Additionally, clinically unaffected skin was also distinguishable from healthy skin for its specific pattern of OD decrease in the reticular dermis (p<0.001). The technique showed an excellent intraobserver and interobserver reliability (intraclass correlation coefficient >0.8). CONCLUSIONS: OCT of the skin could offer a feasible and reliable quantitative outcome measure in SSc. Studies determining OCT sensitivity to change over time and its role in defining skin vasculopathy may pave the way to defining OCT as a valuable imaging biomarker in SSc.

Optical coherence tomography-based optimization of mohs micrographic surgery of Basal cell carcinoma: a pilot study.

BACKGROUND: Optical coherence tomography (OCT) is a noninvasive imaging technique that uses a low-power infrared laser to image up to 2 mm beneath the skin's surface. OBJECTIVE: To test the feasibility and diagnostic value of using in vivo OCT to define excision margins before Mohs micrographic surgery (MMS) of basal cell carcinoma (BCC). METHODS: Patients with biopsy confirmed BCC undergoing MMS were recruited (n = 52). Excision margins defined by experienced dermatologists were compared with those of OCT-assessed borders and validated with histologic assessments. RESULTS: Forty-one (79%) lesions were clear after one MMS procedure; 11 (21%) lesions required a second MMS stage after excision of the clinician-predicted boundary. Generally, the OCT instrument indicated that the estimated clinical margin was 0.4-mm larger than the OCT margin. For lesions requiring a single MMS stage, OCT indicated that lesions were 1.4 ± 1.3 mm smaller than the Mohs excision. Before excision of lesions requiring more than one MMS stage, OCT always indicated that the lesion boundary would extend outside the planned MMS defect boundary. CONCLUSIONS: The present study shows the prospective utility of using OCT to refine clinically estimated borders for MMS. OCT assessment has the potential to reduce the excised area without compromising the integrity of tumor-free borders.