Monitoring efficacy of cryotherapy for superficial basal cell carcinomas with in vivo reflectance confocal microscopy: A preliminary study

Evaluation of confocal laser scanning microscopy in histological classification and photodynamic therapy of low-risk basal cell carcinoma

BACKGROUND

Confocal laser scanning microscopy (CLSM) is a noninvasive technique utilized for identification and analysis of skin malignancies. Several studies have applied CLSM in monitoring the treatment of basal cell carcinoma (BCC).

OBJECTIVES

To investigate the diagnostic value of CLSM in low-risk BCC and the evaluation of photodynamic therapy (PDT).

METHODS

We diagnosed 149 patients with BCC using CLSM and histopathological examination. Based on histopathology, we summarized the classification of low-risk BCC along with imaging features observed through CLSM. Thirty-four patients with low-risk BCC underwent PDT treatment, and we used CLSM to evaluate its efficacy.

RESULTS

Out of 149 BCCs examined by CLSM, 52 were diagnosed as the pigmented type, 87 as the nodular type and 10 as the superficial type. After histopathological examination of the 52 BCCs identified as pigmented by CLSM, 44 out of 52 were seen to be pigmented, 5 were nodular and 3 were superficial. The histopathology results were consistent with CLSM for the 87 nodular and 10 superficial BCCs. The distinguishing CLSM feature of nodular BCC was tissue fissures around the tumour, while the pigmented mass was the CLSM characteristic of the pigmented type. The simultaneous occurrence of inflammation and increased vasculature was characteristic of superficial BCC. The effective rate of PDT was 100%, and the cure rate was 68%. At the 12-month follow-up, the recurrence rate of PDT was 12%; 15% for nodular BCC, 10% for pigmented and 0% for superficial.

CONCLUSIONS

The tissue classification of CLSM for low-risk BCC was consistent with histopathology. CLSM can be used to monitor the -efficacy of PDT for low-risk BCC.

Interobserver agreement on line-field confocal optical coherence tomography image markers in keratinocyte carcinomas and precursor lesions

Line-field confocal optical coherence tomography (LC-OCT) is a new technology for skin cancer diagnostics. However, the interobserver agreement (IOA) of known image markers of keratinocyte carcinomas (KC), including basal cell carcinoma (BCC) and squamous cell carcinoma (SCC), as well as precursors, SCC in situ (CIS) and actinic keratosis (AK), remains unexplored. This study determined IOA on the presence or absence of 10 key LC-OCT image markers of KC and precursors, among evaluators new to LC-OCT with different levels of dermatologic imaging experience. Secondly, the frequency and association between reported image markers and lesion types, was determined. Six evaluators blinded to histopathologic diagnoses, assessed 75 LC-OCT images of KC (21 SCC; 21 BCC), CIS (12), and AK (21). For each image, evaluators independently reported the presence or absence of 10 predefined key image markers of KCs and precursors described in an LC-OCT literature review. Evaluators were stratified by experience-level as experienced (3) or novices (3) based on previous OCT and reflectance confocal microscopy usage. IOA was tested for all groups, using Conger's kappa coefficient (κ). The frequency of reported image marker and their association with lesion-types, were calculated as proportions and odds ratios (OR), respectively. Overall IOA was highest for the image markers lobules (κ = 0.68, 95% confidence interval (CI) 0.57;0.78) and clefting (κ = 0.63, CI 0.52;0.74), typically seen in BCC (94%;OR 143.2 and 158.7, respectively, p < 0.001), followed by severe dysplasia (κ = 0.42, CI 0.31;0.53), observed primarily in CIS (79%;OR 7.1, p < 0.001). The remaining seven image-markers had lower IOA (κ = 0.06-0.32) and were more evenly observed across lesion types. The lowest IOA was noted for a well-defined (κ = 0.07, CI 0;0.15) and interrupted dermal-epidermal junction (DEJ) (κ = 0.06, CI -0.002;0.13). IOA was higher for all image markers among experienced evaluators versus novices. This study shows varying IOA for 10 key image markers of KC and precursors in LC-OCT images among evaluators new to the technology. IOA was highest for the assessments of lobules, clefting, and severe dysplasia while lowest for the assessment of the DEJ integrity.

Looking into the Skin in Health and Disease: From Microscopy Imaging Techniques to Molecular Analysis

The skin is a complex organ that includes a wide variety of tissue types with different embryological origins [...].

Skin Cancer Pathobiology at a Glance: A Focus on Imaging Techniques and Their Potential for Improved Diagnosis and Surveillance in Clinical Cohorts

Early diagnosis is essential for completely eradicating skin cancer and maximizing patients' clinical benefits. Emerging optical imaging modalities such as reflectance confocal microscopy (RCM), optical coherence tomography (OCT), magnetic resonance imaging (MRI), near-infrared (NIR) bioimaging, positron emission tomography (PET), and their combinations provide non-invasive imaging data that may help in the early detection of cutaneous tumors and surgical planning. Hence, they seem appropriate for observing dynamic processes such as blood flow, immune cell activation, and tumor energy metabolism, which may be relevant for disease evolution. This review discusses the latest technological and methodological advances in imaging techniques that may be applied for skin cancer detection and monitoring. In the first instance, we will describe the principle and prospective clinical applications of the most commonly used imaging techniques, highlighting the challenges and opportunities of their implementation in the clinical setting. We will also highlight how imaging techniques may complement the molecular and histological approaches in sharpening the non-invasive skin characterization, laying the ground for more personalized approaches in skin cancer patients.

The skin through reflectance confocal microscopy - Historical background, technical principles, and its correlation with histopathology

Since its first introduction into medical practice, reflectance confocal microscopy (RCM) has been a valuable non-invasive diagnostic tool for the assessment of benign and malignant neoplasms of the skin. It has also been used as an adjunct for diagnosing equivocal cutaneous neoplasms that lack characteristic clinical or dermoscopic features. The use of RCM has led to a decreased number of biopsies of benign lesions. Multiple published studies show a strong correlation between RCM and histopathology thereby creating a bridge between clinical aspects, dermoscopy, and histopathology. Dermatopathologists may potentially play an important role in the interpretation of confocal images, by their ability to correlate histopathologic findings. RCM has also been shown to be an important adjunct to delineating tumoral margins during surgery, as well as for monitoring the non-surgical treatment of skin cancers. Advanced technology with smaller probes, such as the VivaScope 3000, has allowed access to lesions in previously inaccessible anatomic locations. This review explains the technical principles of RCM and describes the most common RCM features of normal skin with their corresponding histological correlation.

Dermoscopy, Reflectance Confocal Microscopy and Optical Coherence Tomography Features of Acne: A Systematic Review

Noninvasive imaging techniques have recently outlined precise microscopic features of acne elementary lesions and accurate quantifications for disease severity staging and therapeutical efficacy follow-up. The aim of this review is to systematically describe current applications of dermoscopy, reflectance confocal microscopy (RCM), and optical coherence tomography (OCT) in acne vulgaris assessment and management. The study followed the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. We included studies conducted on human subjects with elementary lesions of acne vulgaris, reporting assessment of the lesions with dermoscopy, RCM, and/or OCT. At present there are few large studies regarding acne and noninvasive imaging techniques, representing the main limitation of this review. Clinical examination represents the first line in acne diagnosis and treatment. However, dermoscopy, RCM, and OCT are further tools that can improve acne classification, monitoring of treatment, and pathophysiologic characterization. In the near future, dermoscopy, RCM, and OCT could become routinely used for the evaluation of acne vulgaris to provide a deeper knowledge of the disease and to guide the clinician in the prescription of tailored treatment protocols based on each patient’s characteristics.

Optimizing the spray parameters of a cryospray process

Smaller spray zone of single-hole nozzle (SHN) constrains cryospray as a treatment method suitable for lesions having diameter larger than 15 mm on the skin surface. The present study is an attempt to resolve this issue, through the improvement in conventional technique of spraying liquid nitrogen on cancerous lesion. A multi-hole nozzle (MHN) with 5 holes is fabricated to demarcate the variation in outcome when cryogen is sprayed through customised MHN instead of conventional SHN. Special emphasis is placed on reducing the number of sitting required for completion of treatment and increasing the feasibility of cryospray process for larger lesions. Commercial SHN having a hole diameter of 0.8 mm is selected to compare results with the customised MHN having 5 holes of 0.8 mm diameter (4 holes are arranged in a circle of radius 2 mm around the central hole). Single freeze-thaw cycle is carried out to spray liquid nitrogen on tissue mimicking gel. Temperature profile accessed through infrared images advocates that lethal area formed through application of MHN is twice larger than the lethal area formed through the application of SHN on the surface of gel for same spraying distance (z). Thermocouples placed at various locations strengthen the fact that higher cooling rate (CR) corresponding to MHN ensures 15 mm spread of necrotic zone from the centre of spray (CS) and up to a depth of 2 mm from the gel surface while in case of SHN, it is limited to the vicinity of CS. On the basis of observations made through thermal images and digital images, it can be said that the ratio of lateral spread to penetration depth of ice ball remains almost same for SHN and MHN. However, the lateral spread of ice ball formed through the application of MHN is twice larger than SHN while the axial depth of ice ball does not record such increment. This reflects that MHN provides more destruction to superficial skin than SHN. Among the three spraying distances selected (i.e. z = 13 mm, 18 mm and 23 mm), the most optimised spraying distance (z) for MHN is also explored in this study. It has been found that cryoablation is not inversely proportional to the spraying distance. Spraying distance of z = 18 mm provided the most optimised result in terms of cryoablation.

Reflectance confocal microscopy in actinic keratosis-Comparison of efficacy between cryotherapy protocols

BACKGROUND

Actinic keratosis (AK) incidence is increasing. Due to the risk of progression to squamous cell carcinoma, early detection and treatment are essential. The method stated in the European Consensus is cryotherapy, but there is no standard protocol defined for better results.

OBJECTIVES

To compare two different cryotherapy protocols for AK using reflectance confocal microscopy (RCM) as a noninvasive imaging method for evaluation.

METHODS

A self-controlled clinical trial was proposed to compare the efficacy of cryotherapy in two different application protocols. Grade II AKs in the forearms were submitted to freezing and thawing time of 10 seconds for 1 cycle (group A) or 2 cycles (group B). At baseline and 4 weeks after treatment, the same dermatologists assessed RCM evaluation (thickness of horny layer, parakeratosis, dyskeratosis, atypia in spinous layer, fibrosis, and presence of inflammatory cells in epidermis and dermis).

RESULTS

We examined 24 AK lesions in each group. Statistical evaluation of the results evidenced superior response after 2 cycles of cryotherapy in parakeratosis and number of inflammatory cells in epidermis.

CONCLUSION

Both protocols are effective in clearing clinical AK. Two cycles are not generating more side effects (fibrosis) and could reduce the risk of recurrence (better "clearance" of parakeratosis).

Reflectance confocal microscopy for noninvasive examination of nonmelanocytic tumors and virus-associated skin lesions in organ transplant recipients

BACKGROUND

Drug-induced immunosuppression is necessary to prevent rejection of the foreign organ in transplanted patients, but neoplastic and virus-associated skin diseases are frequent complications. Reflectance confocal microscopy (RCM) recently emerged as a promising tool for the early diagnosis of skin lesions.

MATERIALS AND METHODS

A total of 61 skin lesions, among them 20 basal cell carcinomas, six Bowen's diseases, 23 actinic keratoses, and 12 verrucae, were analyzed. All lesions were clinically evaluated followed by RCM evaluation by two independent dermatologists and histological examination.

RESULTS

For the diagnosis of basal cell carcinoma, a sensitivity of 100% by both investigators (INV I + II) and a specificity of 100% by INV I and 80% by INV II were achieved. The sensitivity average rate for RCM features reached by both investigators ranged between 60% and 100%, and the specificity between 55% and 90%. For the diagnosis of actinic keratosis, a concordant sensitivity of 94.4% and a specificity of 80% (INV I) and 60% (INV II) were detected. The sensitivity average rate of specific RCM criteria ranged between 72.3% and 97.2%, whereas specificity ranged between 20% and 90%. Regarding verrucae, RCM confirmed the histological diagnosis with a sensitivity of 85.7% (INV I) and 100% (INV II), while specificity was 100% and 80%, respectively.

CONCLUSION

Reflectance confocal microscopy resulted to be a reliable tool for the noninvasive diagnosis of neoplastic and virus-associated skin changes in organ transplant recipients. Nevertheless, given the frequency and diagnostic complexity of the hyperkeratotic lesions occurring post-transplantation, larger cohorts of patients are required to confirm and consolidate these findings.

A Systematic Review and Meta-Analysis of the Accuracy of in VivoReflectance Confocal Microscopy for the Diagnosis of Primary Basal Cell Carcinoma

Basal cell carcinoma (BCC) is the most common cancer worldwide and its incidence is constantly rising. Early diagnosis and treatment can significantly reduce patient morbidity and healthcare costs. The value of reflectance confocal microscopy (RCM) in non-melanoma skin cancer diagnosis is still under debate. This systematic review and meta-analysis were conducted to assess the diagnostic accuracy of RCM in primary BCC. PubMed, Google Scholar, Scopus, and Web of Science databases were searched up to July 05, 2019, to collect articles concerning primary BCC diagnosis through RCM. The studies’ methodological quality was assessed by the QUADAS-2 tool. The meta-analysis was conducted using Stata 13.0, RevMan 5.0, and MetaDisc 1.4 software. We included 15 studies totaling a number of 4163 lesions. The pooled sensitivity and specificity were 0.92 (95% CI, 0.87–0.95; I² = 85.27%) and 0.93 (95% CI, 0.85–0.97; I² = 94.61%), the pooled positive and negative likelihood ratios were 13.51 (95% CI, 5.8–31.37; I² = 91.01%) and 0.08 (95% CI, 0.05–0.14; I² = 84.83%), and the pooled diagnostic odds ratio was 160.31 (95% CI, 64.73–397.02; I² = 71%). Despite the heterogeneity and risk of bias, this study demonstrates that RCM, through its high sensitivity and specificity, may have a significant clinical impact on the diagnosis of primary BCC.

Current and future applications of confocal laser scanning microscopy imaging in skin oncology

Confocal laser scanning microscopy (CLSM) is a modern imaging technique that enables the in vivo or ex vivo characterization of skin lesions located in the epidermis and superficial dermis with a high quasi-microscopic resolution. Currently, it is considered to be the most promising imaging tool for the evaluation of superficial skin tumors. The in vivo mode adds the advantage of noninvasive, dynamic, in real-time assessment of the tumor associated vasculature and inflammation. It offers the possibility to repeatedly examine the same skin area without causing any damage and to monitor disease progression and treatment outcome. Furthermore, this novel technology allows the evaluation of the entire lesion and can be used to guide biopsies and to define tumor margins before surgical excision or other invasive therapies. CLSM diagnostic features may differentiate between the various histologic subtypes of skin tumors and therefore helps in choosing the best therapeutic approach. In this study, we present the CLSM characteristic features of the most common melanocytic and non-melanocytic skin tumors, as well as future possible CLSM applications in the study of experimental skin tumorigenesis on animal models.

Daylight photodynamic therapy in 25 patients with actinic keratosis and evaluation of efficacy by confocal microscopy

BACKGROUND

Daylight photodynamic therapy (PDT) has been reported as having similar efficacy to conventional photodynamic therapy in actinic keratosis treatment.

METHODS

25 patients with actinic keratosis of the scalp and/or face were submitted to a daylight photodynamic therapy session. Adverse reactions were evaluated after one week and efficacy after 3 months. Confocal Microscopy was performed in 6 patients, before and one week after the treatment. Our aim was to compare our results with others studies and analyse the changes occurring in the epidermis and upper dermis with confocal microscopy.

RESULTS

76% of the patients were male. The mean age was 74.2 years. In 51.7% of patients the treatment site was the scalp. Mean cure rate at 3 months was 74%. Aesthetic results were excellent in all patients and only one patient reported mild pain during the 2 h exposure. Confocal Microscopy showed a normalization of the honeycomb pattern in all of the patients.

CONCLUSIONS

This therapy has similar results to conventional photodynamic therapy and stands out for less discomfort, fewer adverse effects and better cost-effectiveness. Using confocal microscopy it's possible to in vivo demonstrate the efficacy of this method, with normalization of the honeycomb pattern in the epidermis following succcessful PDT.

Comparison of dermoscopy and reflectance confocal microscopy for the diagnosis of malignant skin tumours: a meta-analysis

PURPOSE

Dermoscopy and reflectance confocal microscopy (RCM) are non-invasive methods for diagnosis of malignant skin tumours. The aim of this study was to compare the accuracy of dermoscopy and RCM for the diagnosis of malignant skin tumours.

METHODS

Systematic electronic literature searches were conducted to include PubMed, Medline, Embase, the Cochrane Library database, and Web of Science, up to 26 April 2016. Pooled additional detection rate (ADR), diagnostic accuracy, and 95% confidence intervals (CIs) were calculated using STATA and Meta-Disc analysis.

RESULTS

Eight published studies were included in the analysis, involving 1141 skin lesions, which reported a per-lesion analysis of dermoscopy and RCM. Within the same patient group and at the per-lesion level, RCM significantly increased the detection rate of malignant skin tumours by 7.7% (95% CI 0.01-0.14). The pooled sensitivity of dermoscopy was similar to RCM [88.1% (95% CI 0.85-0.91) vs. 93.5% (95% CI 0.91-0.96)]. The specificity of dermoscopy was significantly lower than that of RCM [52.9% (95% CI 0.49-0.57) vs. 80.3% (95% CI 0.77-0.83)]. The pooled ADR of RCM for melanoma detection was 4.3% (95% CI 0.002-0.08). Pooled sensitivity and specificity of dermoscopy for melanoma detection were 88.4% (95% CI 0.84-0.92) and 49.1% (95% CI 0.45-0.53), respectively. The pooled sensitivity and specificity of RCM were 93.5% (95% CI 0.90-0.96) and 78.8% (95% CI 0.75-0.82), respectively.

CONCLUSIONS

When compared with dermoscopy, RCM has a significantly greater diagnostic specificity for malignant skin tumours and so could improve their detection rate.

The Role of Reflectance Confocal Microscopy in Clinical Trials for Tumor Monitoring

Reflectance confocal microscopy (RCM) allows the evaluation with superb accuracy of some skin tumors before, during, and after treatment. In clinical trials RCM has been shown to provide useful information for evaluation of efficacy of topical or systemic medication. With the recent introduction of handheld RCM a fast examination of the tumor can be done in minutes. In patients treated with surgery RCM plays a unique role to precisely map margins of the tumor in the skin surface and for the detection of subclinical recurrences. This article reviews the use of RCM in the research of different skin cancer tumor treatments.

A meta-analysis of reflectance confocal microscopy for the diagnosis of malignant skin tumours

Early diagnosis is extremely important for treatment and prognosis of skin cancer. Reflectance confocal microscopy (RCM) is a recently developed technique used to diagnose skin cancer. This meta-analysis was carried out to assess the accuracy of RCM for the diagnosis of malignant skin tumours. We conducted a systematic literature search of EMBASE, PubMed, the Cochrane Library and Web of Science database for relevant articles in English published up to 24 December 2015. The quality of the included studies was assessed using the QUADAS-2 tool. Statistical analyses were conducted using the software Meta-Disc version 1.4 and STATA version 12.0. A total of 21 studies involving 3108 patients with a total of 3602 lesions were included in the per-lesion analysis. The corresponding pooled results for sensitivity and specificity were 93.6% (95% CI: 0.92-0.95) and 82.7% (95% CI: 0.81-0.84) respectively. Positive likelihood ratio and negative likelihood ratio were 5.84 (95% CI: 4.27-7.98) and 0.08 (95% CI: 0.07-0.10) respectively. Subgroup analysis showed that RCM had a sensitivity of 92.7% (95% CI: 0.90-0.95) and a specificity of 78.3% (95% CI: 0.76-0.81) for detecting melanoma. The pooled sensitivity and specificity of RCM for detecting basal cell carcinoma were 91.7% (95% CI: 0.87-0.95) and 91.3% (95% CI: 0.94-0.96) respectively. RCM is a valid method of identifying malignant skin tumours accurately.

[Cryosurgery in dermatology]

This article provides information on the clinical development of skin reactions after cryosurgery/cryotherapy and the indications, complications and contraindications of skin cryosurgery. Successful skin cryosurgery requires rapid freezing and slow thawing, minimum tissue temperature of -25 to -60℃ and, in malignant lesions, repetition of the freeze-thaw cycle. Frozen tissue reacts with peripheral erythema immediately after thawing, followed by edema, bulla formation, exudation and mumification. Lesions usually heal with a fine atrophic scar after approximately 4 weeks. Nowadays, cryosurgery is considered the treatment of choice in hypertrophic scars and keloids, granuloma annulare, small capillary infantile hemangioma and isolated actinic keratoses. It is also a valuable alternative therapy for various other skin diseases, including common warts, solar lentigo, superficial basal cell carcinoma and Kaposi's sarcoma. Cryosurgery is a safe regimen with relatively few adverse effects and contraindications. Pain during and/or shortly after treatment, bulla formation and local edema are the major temporary adverse effects; lesional hypopigmentation and/or peripheral hyperpigmentation is the most common long-term complication.

The reflectance confocal microscopy in diagnosis of recurrent basal cell carcinoma

BACKGROUND

Reflectance confocal microscopy (RCM) is very valuable, non-invasive diagnostic tool in the diagnosis of basal cell carcinoma (BCC). Objective: We aimed to demonstrate the positive predictive value (PPV), negative predictive value, sensitivity and specificity of RCM and dermoscopic features in recurrent BCC.

METHODS

The 152 entire lesion sites in 128 patients with BCC were evaluated by clinical examination, dermoscopy and RCM imaging techniques. Biopsy was performed from 46 lesions if there was at least one of the clinical findings or at least one of the diagnostic criteria of BCC with dermoscopy or RCM examination. Histopathological examination was considered as a gold standard for the diagnosis of recurrence BCC.

RESULTS

Recurrence was observed in 29 cases (63%). In the dermoscopic examination, arborizing telangiectasia and blue-grey globules were found to be statistically significantly correlated with BCC recurrence (p<0.05). The specificity and PPV of nucleated corneocytes in the stratum corneum and polarisation of elongated nuclei in the epidermis was 100%. PPV of streaming of aggregated tumour cells and variable refractile stroma was 92% with RCM examination.

CONCLUSION

RCM is a diagnostic tool with a high PPV, sensitivity and specificity for the diagnosis of recurrence of BCC lesions.

Advances in diagnosis and treatment of nonmelanoma skin cancer

The incidence of nonmelanoma skin cancer (NMSC) is rising. Research in the field of these tumors is aimed toward developing earlier and less invasive diagnostic methods and more effective, more accessible therapeutic options. Although there is much advancement in the diagnosis and treatment of NMSC, there are few literatures cataloging these developments. The aim of this review was to present the sensitivity and specificity of new imaging modalities, the dosing regimen and clearance rates of topical treatments, newer systemic treatment modalities, and discuss developments in the use of radiation as a mode of therapy. Recent developments in the diagnosis of NMSC include imaging modalities such as reflectance confocal microscopy, elastic scattering spectroscopy, and spectrophotometric intracutaneous analysis. Recent advances in the treatment of these tumors include systemic therapies such as epidermal growth factor receptor inhibitors, and topical immunomodulating drugs such as imiquimod. The progress in the diagnosis and treatment of these tumors is a gradual but fruitful growth. Scientists and clinicians alike must continue their exploration and study to address these tumors and, hopefully in the future, prevent their occurrence.

Through the looking glass: Basics and principles of reflectance confocal microscopy

Reflectance confocal microscopy (RCM) offers high-resolution, noninvasive skin imaging and can help avoid obtaining unnecessary biopsy specimens. It can also increase efficiency in the surgical setting by helping to delineate tumor margins. Diagnostic criteria and several RCM algorithms have been published for the differentiation of benign and malignant neoplasms. We provide an overview of the basic principles of RCM, characteristic RCM features of normal skin and cutaneous neoplasms, and the limitations and future directions of RCM.

The use of reflectance confocal microscopy for examination of benign and malignant skin tumors

Reflectance confocal microscopy (RCM) is a modern, non-invasive diagnostic method that enables real-time imaging of epidermis and upper layers of the dermis with a nearly histological precision and high contrast. The application of this technology in skin imaging in the last few years has resulted in the progress of dermatological diagnosis, providing virtual access to the living skin erasing the need for conventional histopathology. The RCM has a potential of wide application in the dermatological diagnostic process with a particular reference to benign and malignant skin tumors. This article provides a summary of the latest reports and previous achievements in the field of RCM application in the diagnostic process of skin neoplasms. A range of dermatological indications and general characteristics of confocal images in various types of tumors are presented.

Assessment of changes in lentigo maligna during radiotherapy by in-vivo reflectance confocal microscopy: a pilot study

BACKGROUND

Radiotherapy is an effective treatment for therapy of lentigo maligna (LM).

OBJECTIVES

To investigate the usefulness of in-vivo reflectance confocal microscopy (RCM) in radiotherapy of LM and document the changes within the lesions during treatment.

METHODS

A total of six lesions in six patients were investigated by RCM before, during and after radiotherapy. For diagnostic assessment three observers with experience in RCM diagnosis, blinded as to the stage of treatment, assessed the RCM images of each lesion and documented the findings by consensus.

RESULTS

Epidermal disarray worsened in three patients during radiotherapy and superficial necrosis was observed in four patients. Large pagetoid round/dendritic cells decreased or even vanished during or after radiotherapy. Dilated vessels and apoptotic cells were seen in all patients during radiotherapy as well as an increase of inflammatory cells in the epidermis and dermis in most of the patients. Dendritic cells with small dendrites were observed during radiotherapy in all patients with an increase in number in three patients. Melanophages appeared in five patients at least once during the examination period. All RCM images were assessed correctly by the three observers.

CONCLUSIONS

Reflectance confocal microscopy is a useful method to visualize changes during and after radiotherapy and might also be used for early detection of potential treatment failures. In addition, it might be helpful in planning radiotherapy.

Confocal microscopy patterns in nonmelanoma skin cancer and clinical applications

Reflectance confocal microscopy is currently the most promising noninvasive diagnostic tool for studying cutaneous structures between the stratum corneum and the superficial reticular dermis. This tool gives real-time images parallel to the skin surface; the microscopic resolution is similar to that of conventional histology. Numerous studies have identified the main confocal features of various inflammatory skin diseases and tumors, demonstrating the good correlation of these features with certain dermatoscopic patterns and histologic findings. Confocal patterns and diagnostic algorithms have been shown to have high sensitivity and specificity in melanoma and nonmelanoma skin cancer. Possible present and future applications of this noninvasive technology are wide ranging and reach beyond its use in noninvasive diagnosis. This tool can also be used, for example, to evaluate dynamic skin processes that occur after UV exposure or to assess tumor response to noninvasive treatments such as photodynamic therapy. We explain the characteristic confocal features found in the main nonmelanoma skin tumors and discuss possible applications for this novel diagnostic technique in routine dermatology practice.

Botanical agents for the treatment of nonmelanoma skin cancer

Nonmelanoma skin cancers, including basal cell carcinoma and squamous cell carcinoma, are common neoplasms worldwide and are the most common cancers in the United States. Standard therapy for cutaneous neoplasms typically involves surgical removal. However, there is increasing interest in the use of topical alternatives for the prevention and treatment of nonmelanoma skin cancer, particularly superficial variants. Botanicals are compounds derived from herbs, spices, stems, roots, and other substances of plant origin and may be used in the form of dried or fresh plants, extracted plant material, or specific plant-derived chemicals. They possess multiple properties including antioxidant, anti-inflammatory, and immunomodulatory properties and are, therefore, believed to be possible chemopreventive agents or substances that may suppress or reverse the process of carcinogenesis. Here, we provide a review of botanical agents studied for the treatment and prevention of nonmelanoma skin cancers.

Psoriasis plaque test with confocal microscopy: evaluation of different microscopic response pathways in NSAID and steroid treated lesions

BACKGROUND

Pathophysiology of psoriasis is complex and characterized by microscopic, specific changes. In vivo reflectance confocal microscopy (RCM) provides tissue and cell morphology information in non-invasive way, generating quasi-histologic resolution. Concerning plaque psoriasis, confocal criteria have been described disclosing high agreement between RCM and conventional histology.

OBJECTIVE

We sought to evaluate the in vivo microscopic changes in plaque psoriasis occurring during treatment with two distinct actives (aceclofenac and betamethason).

METHODS

A total of 32 patients with psoriasis were recruited. Two lesions from the same body area or symmetrical were evaluated at baseline and after 3-6 weeks by RCM.

RESULTS

Aceclofenac induced clinical improvement in 32% of patients after 3 weeks and in 76% after 6 weeks. With betamethason, at the end of the 3rd week, the 45% of patients showed improvement that increased to 81% at the end of the study. Single confocal criteria was evaluated and results underwent to statistical analysis considering the modification of the microscopical changes during the two treatments.

CONCLUSION

RCM followed the microscopic changes during treatment and enabled to differentiate effects of different actives. Although data are preliminary and based on a limited sample, aceclofenac seems to be effective in the treatment for psoriasis.

The use of reflectance confocal microscopy for monitoring response to therapy of skin malignancies

SUMMARY

Reflectance confocal microscopy (RCM) is a new non-invasive imaging technique that enables visualizing cells and structures in living skin in real-time with resolution close to that of histological analysis. RCM has been successfully implemented in the assessment of benign and malignant lesions. Most importantly, it also enables monitoring dynamic changes in the skin over time and in response to different therapies, e.g., imiquimod, photodynamic therapy, and others. Given the often traumatic nature of skin cancer that affects both the physiology and the psychology of the patients, it is crucial to have methods that enable monitoring the response to treatment but that minimize the distress and discomfort associated with such process. This article provides a very brief overview of the fundamentals of RCM and then focuses on its recent employment as a monitoring tool in skin cancer and other pathologies that may require frequent follow-up.

In vivo reflectance confocal microscopy: usefulness for diagnosing hair diseases

BACKGROUND

Reflectance confocal laser scanning microscopy (R-CSLM) is a new diagnostic technique which allows visualization of "optical intersections" within the epidermis and superficial layers of the dermis. Outlines of cells and their architecture are imaged and may be analyzed both horizontally and vertically to the skin surface. The method proved useful in early melanoma detection. We evaluated the potential usefulness of this method in a short series of patients with hair diseases.

MAIN OBSERVATIONS

Two healthy persons and 6 patients with hair diseases (1 with alopecia areata, 1 with androgenic alopecia and 4 with genetic hair shaft abnormalities) were examined with the use of Vivascope 1500. In all patients one scalp location and one location in the mid forearm were evaluated. R-CSLM examination gave in all cases high quality images of the hair shaft intersections, at 1µm intervals, which allowed detailed analysis of the hair structure. Hair follicles could be partly visualized at a depth of up to 200µm, which allowed analysis of only superficial parts of the hair follicles. An additional hurdle was bright reflection within the follicular ostia, which decreased the perception of details in these images. Hair could be best visualized, when analyzed on flat surfaces. Receiving good quality images from convex surfaces on the scalp required additional effort from the patient (to not move) and from the physician (to obtain best possible fit of the "optic window" to the scalp).

CONCLUSIONS

These preliminary data show that R-CSLM may develop into a valuable tool in evaluation of hair shaft diseases. Further development is needed to apply this technique in abnormalities of the hair follicle and the perifollicular area.

Reflectance confocal microscopy for the evaluation of acute epidermal wound healing

The dynamic process of wound healing is routinely evaluated by clinical or histological evaluation. Recently, a number of non-invasive imaging techniques have been evaluated for their clinical applicability in dermatology. Among them, reflectance confocal microscopy (RCM) represents a non-invasive imaging technique that allows the in vivo characterization of the skin at near-histological resolution. The aim of this study was to monitor epidermal wound repair using RCM in a model of tissue damage induced by cryosurgery. For this purpose, contact cryosurgery was performed at -32 °C for 10 seconds on the volar forearm of five healthy volunteers. Clinical and RCM evaluations were performed at nine consecutive time points. RCM allowed the visualization of edema formation and blood vessel dilatation immediately after cryosurgery, as well as morphologic features of wound repair, including the formation of finger-like protusions of keratinocytes into the wound bed, the appearance of hairpin-like vessels, and inflammatory cells. This pilot study illustrates that RCM represents a promising technique for quasi-real-time monitoring the kinetics of wound repair non-invasively and over time, thus offering new insights into in vivo processes of cutaneous wound repair and angiogenesis, as well as potential effects of topically applied drugs on the process of tissue repair.

Up-to-date non-invasive visualization technologies in dermatology

The authors present a review of up-to-date non-invasive visualization methods used in diagnostics of diseases of skin and its appendages. They describe physical principles forming the basis for non-invasive visualization methods such as dermatoscopy, confocal laser scanning microscopy, optical video monitoring, optical topometry, optical coherent tomography, ultrasound scanning, 3D-modeling. They also describe the potential of practical application of these diagnostics methods at the current stage of their development. The authors have demonstrated that it is possible to reduce the clinicians need in biopsy diagnostics due to the high information value of non-invasive visual diagnostics methods.

First experiences using reflectance confocal microscopy on equivocal skin lesions in Queensland

BACKGROUND/OBJECTIVES

Reflectance confocal microscopy (RCM) is a non-invasive method of imaging human skin in vivo. The purpose of this study was to observe the experience of using RCM on equivocal skin lesions in a tertiary clinical setting in Queensland.

METHODS

Fifty equivocal lesions on 42 patients were imaged using a reflectance confocal microscope immediately prior to being excised. The images were then analysed blind to the histopathological diagnosis. The experience and problems encountered when using RCM on skin lesions for the first time was also observed.

RESULTS

On RCM analysis 12/13 melanomas (92.3% sensitivity, 75% specificity), 19/22 benign naevi (86% sensitivity, 95% specificity), 6/9 basal cell carcinomas (66.7% sensitivity, 100% specificity)and 6/6 squamous cell carcinomas and its precursors (100% sensitivity, 75% specificity) were diagnosed correctly when using histology as the gold standard. We identified three common problems that affected image quality: object artefacts; positioning artefacts; and movement artefacts.

CONCLUSIONS

Using simple techniques we found that common RCM features were readily identifiable and common artefacts could be minimized, making RCM a useful tool to aid the diagnosis of equivocal skin lesions in a clinical setting.

In vivo fluorescence confocal microscopy: indocyanine green enhances the contrast of epidermal and dermal structures

In recent years, in vivo skin imaging devices have been successfully implemented in skin research as well as in clinical routine. Of particular importance is the use of reflectance confocal microscopy (RCM) and fluorescence confocal microscopy (FCM) that enable visualization of the tissue with a resolution comparable to histology. A newly developed commercially available multi-laser device in which both technologies are integrated now offers the possibility to directly compare RCM with FCM. The fluorophore indocyanine green (ICG) was intradermally injected into healthy forearm skin of 10 volunteers followed by in vivo imaging at various time points. In the epidermis, accurate assessment of cell morphology with FCM was supplemented by identification of pigmented cells and structures with RCM. In dermal layers, only with FCM connective tissue fibers were clearly contoured down to a depth of more than 100 μm. The fluorescent signal still provided a favorable image contrast 24 and 48 hours after injection. Subsequently, ICG was applied to different types of skin diseases (basal cell carcinoma, actinic keratosis, seborrhoeic keratosis, and psoriasis) in order to demonstrate the diagnostic benefit of FCM when directly compared with RCM. Our data suggest a great impact of FCM in combination with ICG on clinical and experimental dermatology in the future.

Effectiveness and limitations of reflectance confocal microscopy in detecting persistence of basal cell carcinomas: a preliminary study

BACKGROUND/OBJECTIVES

Reflectance confocal microscopy (RCM) can accurately and non-invasively diagnose basal cell carcinoma (BCC). The use of RCM in assessing responses to saucerization or curettage and cautery of BCC has not been established. The aim of the present study was to expound the usefulness of RCM in assessing treatment responses of BCC to saucerization or curettage and cautery 8-12 weeks after treatment.

METHODS

Eight sequential patients, with 11 superficial BCCs, were recruited. Lesions were evaluated clinically and dermoscopically. Three operators performed RCM imaging for each BCC at baseline and 8-12 weeks after treatment. Diagnostic criteria for RCM diagnosis included streaming of basal cells and the presence of cord-like structures and horizontal vessels. Results were compared against histopathology. Difficulties in establishing tumour clearance were identified and the effectiveness of RCM in assessing the response to treatment was explored.

RESULTS

At baseline, all lesions were consistent with superficial BCC. At 8-12 weeks after treatment, RCM correctly diagnosed 10 of 11 lesions as tumour free. Furthermore, RCM was reliable across operators of variable experience and the findings were confirmed histopathologically. Limitations were identified, but appeared to be related to operator experience.

CONCLUSION

The diagnosis of BCC was straightforward and reliable in the present study. Thus, RCM appears useful in assessing the early treatment response of superficial BCC treated with saucerization or curettage and cautery despite operator-dependent limitations.

Diagnosis of cutaneous tumors with in vivo confocal laser scanning microscopy

In recent years, in vivo confocal laser scanning microscopy (CLSM) has become an established method for the non-invasive examination of the skin. In vivo CLSM allows for real-time imaging of micro-anatomic cutaneous structures. It has been used to diagnose ambiguous skin tumors and to measure subclinical tumor spread prior to surgery. By additionally providing high power morphologic information, in vivo CLSM helps to reduce unnecessary biopsies. A multitude of diagnostic features for skin tumors has been published. Here we review published diagnostic in vivo CLSM features, and compare them to our own experience in 100 tumors. In combination with clinical examination and dermatoscopy, in vivo CLSM is a valuable additional tool for non-invasive skin tumor diagnosis.