In Vivo and Ex Vivo Confocal Microscopy for Dermatologic and Mohs Surgeons

Chang

Skin Research and Technology

et al. 2019

Background Studies have reported the application of conventional optical coherence tomography (OCT) in the diagnosis of basal cell carcinoma (BCC). The new OCT provides cellular details similar to those in pathology slides and may reduce user learning time. This study aimed to demonstrate the quality of ex vivo full‐field cellular‐resolution OCT images and compare the diagnostic accuracy between physicians with varying pathology experience. Materials and Methods Sixty histologically confirmed BCCs were selected. Tissue samples were sectioned and scanned using OCT, and their features were compared with those of hematoxylin and eosin (H&E)‐stained sections. Thirty images were selected for the test administered to dermatology residents, dermatopathology fellows, and board‐certified general pathologists without any OCT experience. The pretest learning included a 3‐min instruction and 10‐min self‐study of four BCC variants. Results Histopathological BCC and normal histological features were clearly recognizable on the OCT images. The pathological BCC features observed in the OCT images correlated with those found in the H&E‐stained sections. Seven participants completed the test. The correct answer rates of the residents, fellows, and pathologists were 71%, 68%, and 83% for BCC and 44%, 57%, and 57% for the BCC subtypes, respectively. Conclusion All the participants identified BCC in >70% cases with a learning time of only 13 minutes. The results indicated that cellular‐resolution OCT provided high‐quality images similar to the conventional pathology slides. Pathology experience did reflect the diagnostic accuracy. However, a longer training time is still needed at all levels to recognize the BCC subtypes correctly.

Section: Discussioncontrasting

confidence: 61%

Section: Discussionmentioning

confidence: 94%

Ex vivo full‐field cellular‐resolution optical coherence tomography of basal cell carcinomas: A pilot study of quality and feasibility of images and diagnostic accuracy in subtypes

Chang

Skin Research and Technology

et al. 2019

“…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 …”

Section: Introductionmentioning

confidence: 99%

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

Banzhaf

Phothong

Suku

et al. 2019

Acad Dermatol Venereol

Background Basal cell carcinomas (BCCs) have previously been treated off‐label with ingenol mebutate (IM). Ablative fractional laser (AFL) may improve efficacy of IM by increasing drug uptake in the tumour. Optical coherence tomography (OCT) and reflectance confocal microscopy (RCM) detect BCC non‐invasively. Our aim was to investigate BCC response and tolerability after combined AFL and IM treatment of low‐risk BCCs. Methods Twenty patients with histologically verified superficial (n = 7) and nodular (n = 13) BCCs were treated with combined fractional CO2‐laser (10 600 nm) and IM 0.015% or 0.05%, the concentration depending on anatomical location. BCC response was evaluated clinically, by OCT and RCM at day 29 and 90 after first treatment, and histologically at day 90. Treatment was repeated at day 29 if BCC persisted. Local skin reactions (LSRs) were assessed using LSR scale at all visits. Results At day 29, 18/20 patients received a second treatment due to residual BCC detected clinically, by OCT or RCM. OCT and RCM presented subclinical BCCs in five of 20 cases (25%). At day 90, overall histological cure rate was 70%, corresponding to clinical (65%) and OCT/RCM (60%) cure rates, and agreement between evaluation methods was substantial (kappa ≥ 0.796, P < 0.0001). Clearance rates were similar for sBCCs and nBCCs (P = 0.354) and for lesions treated with IM 0.015% and 0.05% (P = 0.141). LSRs were tolerable, but scarring was observed in the majority of cleared patients. Conclusion Two treatments of combined AFL and IM show potential to treat low‐risk BCCs with acceptable tolerability. OCT and RCM show promise to detect subclinical BCCs at short‐term follow‐up.

“…Early adopter Mohs surgeons have reported high sensitivity (89% to 96%) and high specificity (99% to 89%) in six reasonably large studies, involving reasonably large numbers (17 to 80) of tissue specimens. 53 The consistency of these results across diverse settings (New York, Barcelona, Modena) suggests that the current technical limitations (mainly consistency for tissue flattening, uneven stitching, and irregular contrast agent uptake), although yet to be fully resolved, may ultimately have relatively minor-to-small impact on the overall ability and utility of this approach to offer a means to perform rapid pathology in fresh tissue. In at least three studies, senior Mohs surgeons with a lot of experience and expertise in reading confocal mosaics were able to train junior surgeons (and confocal imaging novices) in a matter of few months.…”

Section: Resultsmentioning

confidence: 99%

Implementation of fluorescence confocal mosaicking microscopy by “early adopter” Mohs surgeons and dermatologists: recent progress

2017

Self Cite

Manu Jain, Milind Rajadhyaksha, Kishwer Nehal, "Implementation of fluorescence confocal mosaicking microscopy by "early adopter" Mohs surgeons and dermatologists: recent progress," J. Abstract. Confocal mosaicking microscopy (CMM) enables rapid imaging of large areas of fresh tissue ex vivo without the processing that is necessary for conventional histology. When performed in fluorescence mode using acridine orange (nuclear specific dye), it enhances nuclei-to-dermis contrast that enables detection of all types of basal cell carcinomas (BCCs), including micronodular and thin strands of infiltrative types. So far, this technique has been mostly validated in research settings for the detection of residual BCC tumor margins with high sensitivity of 89% to 96% and specificity of 99% to 89%. Recently, CMM has advanced to implementation and testing in clinical settings by "early adopter" Mohs surgeons, as an adjunct to frozen section during Mohs surgery. We summarize the development of CMM guided imaging of ex vivo skin tissues from bench to bedside. We also present its current state of application in routine clinical workflow not only for the assessment of residual BCC margins in the Mohs surgical setting but also for some melanocytic lesions and other skin conditions in clinical dermatology settings. Last, we also discuss the potential limitations of this technology as well as future developments. As this technology advances further, it may serve as an adjunct to standard histology and enable rapid surgical pathology of skin cancers at the bedside.