Christina Alette Banzhaf

Optical coherence tomography imaging of non-melanoma skin cancer undergoing photodynamic therapy reveals subclinical residual lesions

BACKGROUND Photodynamic therapy with methyl aminolaevulinate (MAL-PDT) is a widely used non-invasive treatment modality for non-melanoma skin cancer (NMSC). The outcome of MAL-PDT is usually primarily evaluated clinically. Optical coherence tomography (OCT) is a non-invasive imaging technology based on interferiometry. OCT has been proven to provide high accuracy in identifying NMSC lesions and performing thickness measurements of thin tumours. OBJECTIVES To describe the OCT morphology in in-vivo NMSC lesions during MAL-PDT treatment and to investigate the use of OCT in evaluating the response of MAL-PDT treated NMSC lesions. METHODS A total of 18 biopsy-proven basal cell carcinomas and actinic keratoses were monitored by OCT during 2 sessions of MAL-PDT treatment. At 3-months follow-up the patients were assessed both by OCT and clinically. If the clinical and OCT evaluation came to different conclusions on recurrence of the lesion, patients were followed more closely at clinical appointments for up to one year after the PDT treatment. RESULTS All lesions displayed at least one OCT characteristic before MAL-PDT treatment. At 3 months follow-up, recurrence was suspected clinically in 5/18 cases, with OCT in 7/18 cases. OCT correctly identified all of the partial responses also found by the clinical examinations. In both cases where recurrence was only found in OCT, this was subsequently confirmed by histology. CONCLUSIONS Our study suggests that OCT identified 29% more recurrences than clinical examination alone. OCT can detect subclinical residual NMSC lesions after MAL-PDT treatment and may therefore be an accurate tool for early detection of residual lesional tissue.

Optical coherence tomography imaging of non-melanoma skin cancer undergoing imiquimod therapy

To explore the application of optical coherence tomography (OCT) imaging of basal cell carcinomas (BCC) and actinic keratosis (AK) before, during and after imiquimod treatment and the ability of OCT to predict treatment outcome.

Spatiotemporal closure of fractional laser-ablated channels imaged by optical coherence tomography and reflectance confocal microscopy.

Optical coherence tomography (OCT) and reflectance confocal microscopy (RCM) offer high‐resolution optical imaging of the skin, which may provide benefit in the context of laser‐assisted drug delivery. We aimed to characterize postoperative healing of ablative fractional laser (AFXL)‐induced channels and dynamics in their spatiotemporal closure using in vivo OCT and RCM techniques.

Cryosurgery treatment of actinic keratoses monitored by optical coherence tomography: a pilot study.

Background: Optical coherence tomography (OCT) is a non-invasive optical imaging technique providing high-resolution images. OCT may be useful as a monitoring tool during treatment of actinic keratoses (AK) and skin cancer. Objective: To examine and describe how OCT skin morphology changes when the tissue is exposed to the effects of cryotherapy. Methods: Normal ex vivo skin and in vivo AK lesions were examined. Cryotherapy was applied and OCT images were acquired at defined time points. OCT morphology was described. Results: Cryotherapy treatment produced an opaque iceball, and freezing depth could not be monitored by OCT. Vesicle formation after cryotherapy could be identified in OCT images. In ex vivo skin no vesicle formation occurred. Conclusion: OCT cannot monitor the freezing depth, but OCT was able to visualise AK lesions and vesicle formation shortly after cryotherapy. Results add to the assumption that OCT could be used in monitoring non-invasive treatments.

Imaging of collagen deposition disorders using optical coherence tomography

Collagen deposition disorders such as hypertrophic scars, keloids and scleroderma can be associated with significant stigma and embarrassment. These disorders often constitute considerable impairment to quality of life, with treatment posing to be a substantial challenge. Optical coherence tomography (OCT) provides a non‐invasive, easily applicable bedside optical imaging method for assessment of the skin. It is hypothesized that OCT imaging may be useful in assessing fibrosis to avoid additional biopsies that could potentially worsen the scarring.

Dynamic Optical Coherence Tomography Capillaroscopy: A New Imaging Tool in Autoimmune Connective Tissue Disease

Importance Vasculopathy characterized by functional and structural abnormalities of the microcirculation plays an important role in systemic sclerosis and dermatomyositis. Although there are several advantages in using capillaroscopy, the method does not offer insight on the skin architecture, flow status, or morphology of the deeper dermal vessels. Dynamic optical coherence tomography (D-OCT) is a recently developed OCT technique that enables detection of high-speed changes in back-scattered light caused by moving cells in vessels. The high resolution of OCT enables the detection of the papillary loops. Objective To explore the potential for OCT capillaroscopy of the nailfolds using D-OCT. Design, Setting, and Participants In this case series study of 4 participants, the nailfolds in 2 patients with systemic sclerosis, 1 patient with dermatomyositis, and a healthy volunteer were scanned using D-OCT. The included patients were all outpatients from the department of dermatology at Bispebjerg Hospital. Data were analyzed from November 2015 to February 2016. Main Outcomes and Measures Dynamic OCT capillaroscopy revealed a potential for imaging of the capillary morphology, the surrounding skin architecture, and flow status of the capillaries in the nailfold. Moreover, D-OCT quantified evident changes of the blood flow in normal nailfold capillaries after application of nitroglycerine and brimonidine. Results This case series included 4 adult women. The quantitative measurements of the blood flow in the D-OCT images of the healthy participant showed significant quantitative differences in blood flow before and after application of nitroglycerine (mean difference, 0.035; 95% CI, 0.008-0.061; P = .02) and brimonidine (mean difference, -0.015; 95% CI, -0.082 to -0.039; P < .001). In the dermatomyositis patient, the en face D-OCT images showed a striking detailed Y-shaped dilated capillary correlating with the clinical finding. In the 2 patients with systemic sclerosis, D-OCT depicted megacapillaries, as well as loss of capillaries. Moreover, cross-sectional OCT images demonstrated a characteristic loss of distinct dermo-epidermal junction and more compact dermis with loss of adnexal structures. Conclusions and Relevance Compared with conventional capillaroscopy, D-OCT offers second-to-none information on nailfold capillary morphology, overall skin architecture, as well as quantitative data on vascular abnormalities and blood flow in the nailfold in a single scan.

In vivo Imaging of Sarcoptes scabiei Infestation Using Optical Coherence Tomography

Background:Sarcoptes scabiei can be visualized with different imaging tools. Optical coherence tomography (OCT) may have the potential to describe the changes in skin morphology due to scabies infestation and visualize the parasite. Methods: Five patients from the Departments of Dermatology, Augsburg, Germany, and Roskilde, Denmark, were OCT scanned (VivoSight®; Michelson Diagnostics Ltd., UK). Mites were identified by epiluminescence and light microscopy to confirm the diagnosis. Results: OCT identified S. scabiei mites in all patients in vivo. Mites and burrows were visualized, and some detail on burrow content was provided. Conclusion: OCT can visualize S. scabiei mites in vivo, suggesting that it may be used to study the biology of the mites in vivo and provide early assessment of scabicide therapy. OCT is able to visualize structures in the skin with an 8-µm resolution. Therefore, this technology could potentially allow rapid, non-invasive, in vivo diagnosis and analysis of infestations.

Fractional laser-assisted drug uptake: impact of time-related topical application to achieve enhanced delivery

Ablative fractional laser (AFXL) is acknowledged to increase uptake of topically applied agents in skin. AFXL channels gradually close over time, which may impair this capability. The time frame for applying a drug after AFXL exposure remains to be established. The aim of this study, was to investigate the importance of time‐related topical application after AFXL exposure and to relate resultant uptake in skin with AFXL channel morphology and skin integrity.

Imaging Granulomatous Lesions with Optical Coherence Tomography

Aim: To investigate and compare the presentation of granulomatous lesions in optical coherence tomography (OCT) images and compare this to previous studies of nonmelanoma skin tumors. Methods: Two patients with granulomas, tophi and granuloma annulare (GA), respectively, were photographed digitally, OCT-scanned and biopsied in the said order. Normal skin was OCT-scanned for comparison, but not biopsied. The OCT images from each lesion were compared with their histologic images as well as with OCT images with similar characteristics obtained from nonmelanoma skin tumors. Results: The OCT images of the tophi showed hyperreflective, rounded cloud-like structures in dermis, their upper part sharply delineated by a hyporeflective fringe. The deeper areas appeared blurred. The crystalline structures were delineated by a hyporeflective fringe. OCT images of GA showed two different structures in dermis: a hyporeflective rounded one, and one that was lobulated and wing-like. Conclusion: Granulomatous tissue surrounding urate deposits appeared as a clear hyporeflective fringe surrounding a light, hyperreflective area. The urate crystals appeared as hyperreflective areas, shielding the deeper part of dermis, meaning OCT could only visualize the upper part of the lesions. The lobulated, wing-like structure in GA may resemble diffuse GA or a dense lymphocytic infiltrate as seen on histology. The rounded structure in GA may represent an actual granuloma or either diffuse GA or a dense lymphocytic infiltrate as described above. This case suggests that OCT images granulomatous tissue as absorbent, hyporeflective areas, and urate crystals appear as reflective areas, obscuring the underlying tissue. In GA a new image shape looking like a wing has been found. The frequency, specificity and sensitivity of this new pattern in OCT imaging will require further studies.

The fractional laser-induced coagulation zone characterized over time by laser scanning confocal microscopy-A proof of concept study: FRACTIONAL LASER-INDUCED COAGULATION ZONE

Ablative fractional laser (AFXL) is an acknowledged technique to increase uptake of topical agents in skin. Micro thermal ablation zones (MAZs) consist of ablated vertical channels surrounded by a coagulation zone (CZ). Laser scanning confocal microscopy (LSCM) images individual MAZs at 733 nm (reflectance confocal microscopy (RCM)). Further, LSCM can image sodium fluorescein (NaF) fluorescence with 488 nm excitation (fluorescence confocal microcopy (FCM)), a small hydrophilic test molecule (370 MW, log P ‐1.52), which may simulate uptake, bio‐distribution and kinetics of small hydrophilic drugs.