In vivoconfocal microscopy efficacy assessment of daylight photodynamic therapy in actinic keratosis patients

Vascular feature identification in actinic keratosis grades I-III using dynamic optical coherence tomography with automated, quantitative analysis

Clinical grading of actinic keratosis (AK) is based on skin surface features, while subclinical alterations are not taken into consideration. Dynamic optical coherence tomography (D-OCT) enables quantification of the skin´s vasculature, potentially helpful to improve the link between clinical and subclinical features. We aimed to compare microvascular characteristics across AK grades using D-OCT with automated vascular analysis. This explorative study examined AK and photodamaged skin (PD) on the face or scalp. AKs were clinically graded according to the Olsen Classification scheme before D-OCT assessment. Using an open-source software tool, the OCT angiographic analyzer (OCTAVA), we quantified vascular network features, including total and mean vessel length, mean vessel diameter, vessel area density (VAD), branchpoint density (BD), and mean tortuosity from enface maximum intensity projection images. Additionally, we performed subregional analyses on selected scans to overcome challenges associated with imaging through hyperkeratosis (each lesion group; n = 18). Our study included 45 patients with a total of 205 AKs; 93 grade I lesions, 65 grade II, 47 grade III and 89 areas with PD skin. We found that all AK grades were more extensively vascularized relative to PD, as shown by greater total vessel length and VAD (p ≤ 0.009). Moreover, AKs displayed a disorganized vascular network, with higher BD in AK I-II (p < 0.001), and mean tortuosity in AK II-III (p ≤ 0.001) than in PD. Vascularization also increased with AK grade, showing significantly greater total vessel length in AK III than AK I (p = 0.029). Microvascular quantification of AK unveiled subclinical, quantitative differences among AK grades I-III and PD skin. D-OCT-based microvascular assessment may serve as a supplement to clinical AK grading, potentially raising perspectives to improve management strategies.

Digitally Enhanced Methods for the Diagnosis and Monitoring of Treatment Responses in Actinic Keratoses: A New Avenue in Personalized Skin Care

Non-melanocytic skin cancers represent an important public health problem due to the increasing incidence and the important local destructive potential. Thus, the early diagnosis and treatment of precancerous lesions (actinic keratoses) is a priority for the dermatologist. In recent years, non-invasive skin imaging methods have seen an important development, moving from simple observational methods used in clinical research, to true diagnostic and treatment methods that make the dermatologist's life easier. Given the frequency of these precancerous lesions, their location on photo-exposed areas, as well as the long treatment periods, with variable, imprecise end-points, the need to use non-invasive imaging devices is increasingly evident to complete the clinical observations in the diagnosis and treatment of these lesions, with the aim of increasing accuracy and decreasing the adverse effects due to long treatment duration. This is the first review that brings together all skin imaging methods (dermoscopy, reflectance confocal microscopy, ultrasonography, dermoscopy-guided high frequency ultrasonography, and optical coherence tomography) used in the evaluation of actinic keratoses and their response to different treatment regimens.

Photodynamic Therapy is an Effective Treatment of Facial Pigmented Actinic Keratosis

BACKGROUND

Actinic keratosis (AK), or solar keratosis, is a precancerous condition of the skin, mainly caused by excessive and chronic exposure to ultraviolet radiation. Pigmented AK (pAK) is a rare variant of AK. Photodynamic therapy (PDT) is widely used to treat the classical variant of AK, but very limited data are available on the use of PDT in patients with pAK. The objective of this study was to assess the usefulness of PDT in the treatment of pAK.

METHODS

The study included 16 patients with 20 pAK lesions treated with PDT. All skin lesions were clinically and dermatoscopically assessed for typical features characteristic of pAK. Reflectance confocal microscopy (RCM) was also used to assess keratinocyte atypia, confirm pAK diagnosis, and rule out other disease entities.

RESULTS

After three PDT sessions, the complete resolution of all clinical features of pAK was observed in 80% of the studied lesions. Dermatoscopically, 65% of the lesions achieved 100% response and no cellular atypia was seen in the follow-up RCM images of 85% of lesions.

CONCLUSIONS

Photodynamic therapy is an effective treatment modality for pAK in fair-skinned individuals.

In Vivo Reflectance Confocal Microscopy as a Response Monitoring Tool for Actinic Keratoses Undergoing Cryotherapy and Photodynamic Therapy

Simple Summary

The assessment of actinic keratoses (AKs) in prevention and therapeutic trials, as well as clinical practice, could significantly benefit from the incorporation of non-invasive imaging technology. Such technology has the potential to enhance the objective evaluation of clinical and subclinical AKs with the added advantage of sequential monitoring. In vivo reflectance confocal microscopy (RCM) allows for the non-invasive imaging of AKs at a cellular level. We aimed to establish an in in vivo RCM protocol for AK response monitoring, ultimately leading to more reliable characterization of longitudinal responses and therapy optimization.

Abstract

Reflectance confocal microscopy (RCM) presents a non-invasive method to image actinic keratosis (AK) at a cellular level. However, RCM criteria for AK response monitoring vary across studies and a universal, standardized approach is lacking. We aimed to identify reliable AK response criteria and to compare the clinical and RCM evaluation of responses across AK severity grades. Twenty patients were included and randomized to receive either cryotherapy (n = 10) or PDT (n = 10). Clinical assessment and RCM evaluation of 12 criteria were performed in AK lesions and photodamaged skin at baseline, 3 and 6 months. We identified the RCM criteria that reliably characterize AK at baseline and display significant reduction following treatment. Those with the highest baseline odds ratio (OR), good interobserver agreement, and most significant change over time were atypical honeycomb pattern (OR: 12.7, CI: 5.7–28.1), hyperkeratosis (OR: 13.6, CI: 5.3–34.9), stratum corneum disruption (OR: 7.8, CI: 3.5–17.3), and disarranged epidermal pattern (OR: 6.5, CI: 2.9–14.8). Clinical evaluation demonstrated a significant treatment response without relapse. However, in grade 2 AK, 10/12 RCM parameters increased from 3 to 6 months, which suggested early subclinical recurrence detection by RCM. Incorporating standardized RCM protocols for the assessment of AK may enable a more meaningful comparison across clinical trials, while allowing for the early detection of relapses and evaluation of biological responses to therapy over time.

In vivo reflectance confocal microscopy for monitoring actinic keratosis treated with 5-aminolevulinic acid photodynamic therapy

BACKGROUND

Actinic keratosis (AK) occurs frequently in sun-exposed skin while its diagnosis and treatment were still in exploration.

MATERIALS AND METHODS

Thirty two patients with facial AK lesions were selected and examined with reflective confocal microscopy (RCM) firstly, followed by biopsy at the same site. RCM was used to observe AK lesions before 5-aminolevulinic acid photodynamic therapy (ALA-PDT) treatment, after the first treatment, after 4 treatments, and at 1 and 6 months follow-up. Retrospective analysis of RCM images was performed.

RESULTS

Thirty two AK cases showed initial RCM microscopic features including disorderly arranged epidermal cells (100%), atypical keratinocytes (100%), and blurry border between the epidermis and dermis (100%). 4 patients quitted trail. After treatments, 24 cases showed basically regular arrangement of epidermal cells, absent atypical keratinocytes, and clear border between epidermis and dermis, while 4 cases improved little. At 1 and 6 months follow-up, 23 cases remained relapse-free while 1 case developed recurrent symptoms. Effective rate of 4 ALA-PDT treatments for AK was 100%; recurrence and cure rates were 4.2% and 82.1%, respectively.

CONCLUSION

ALA-PDT is effective to treat AK, while RCM can be recommended for in vivo evaluating and monitoring the effect of ALA-PDT on AK.

Squamous Cell Carcinoma: An Update on Diagnosis and Treatment

Squamous cell carcinoma (SCC) accounts for most nonmelanoma skin cancer-related metastatic disease and deaths. Histopathology and correct surgical excision remain the gold standard for the diagnosis and treatment of SCC; however, new diagnostic imaging techniques such as dermoscopy and reflectance confocal microscopy have increased the diagnostic accuracy in terms of early recognition, better differential diagnosis, more precise selection of areas to biopsy, and noninvasive monitoring of treatments. The therapeutic intervention in patients with severe actinic damage and multiple in situ/low-risk SCC, and the development of innovative treatments such as epidermal growth factor receptor inhibitors and immune checkpoint inhibitors for locally advanced and metastatic SCC, are improving considerably the approach to the disease. This review summarizes the up-to-date knowledge in the field of detection, treatment, and monitoring of cutaneous SCC.

Identification of differentially expressed genes in actinic keratosis samples treated with ingenol mebutate gel

Actinic keratosis is a common skin disease that may progress to invasive squamous cell carcinoma if left untreated. Ingenol mebutate has demonstrated efficacy in field treatment of actinic keratosis. However, molecular mechanisms on ingenol mebutate response are not yet fully understood. In this study, we evaluated the gene expression profiles of actinic keratosis lesions before and after treatment with ingenol mebutate using microarray technology. Actinic keratoses on face/scalp of 15 immunocompetent patients were identified and evaluated after treatment with topical ingenol mebutate gel 0.015%, applied once daily for 3 consecutive days. Diagnostic and clearance of lesions was determined by clinical, dermoscopic, and reflectance confocal microscopy criteria. Lesional and non-lesional skin biopsies were subjected to gene expression analysis profiled by Affymetrix microarray. Differentially expressed genes were identified, and enrichment analyses were performed using STRING database. At 8 weeks post-treatment, 60% of patients responded to ingenol mebutate therapy, achieving complete clearance in 40% of cases. A total of 128 differentially expressed genes were identified following treatment, and downregulated genes (114 of 128) revealed changes in pathways important to epidermal development, keratinocyte differentiation and cornification. In responder patients, 388 downregulated genes (of 450 differentially expressed genes) were also involved in development/differentiation of the epidermis, and immune system-related pathways, such as cytokine and interleukin signaling. Cluster analysis revealed two relevant clusters showing upregulated profile patterns in pre-treatment actinic keratoses of responders, as compared to non-responders. Again, differentially expressed genes were mainly associated with cornification, keratinization and keratinocyte differentiation. Overall, the present study provides insight into the gene expression profile of actinic keratoses after treatment with ingenol mebutate, as well as identification of genetic signatures that could predict treatment response.

Photodynamic therapy: A hot topic in dermato-oncology

Photodynamic therapy (PDT) is a modern, non-invasive therapeutic method used for the destruction of various cells and tissues. It requires the simultaneous presence of three components: a photosensitizer (PS), a light source and oxygen. Precancerous skin lesions are conditions associated with a high likelihood of malignant transformation to squamous cell carcinoma. Data available so far indicate that PDT is a promising treatment method which can be successfully employed in several medical fields including dermatology, urology, ophthalmology, pneumology, cardiology, dentistry and immunology. Numerous authors therefore have studied this technique in order to improve its efficacy. As a result, significant advancement has been achieved with regard to PSs and drug delivery systems. Substantial progress was also obtained with respect to PDT for the treatment of precancerous skin lesions, several authors focusing their efforts on the study of daylight-PDT and on identifying methods of decreasing technique-related pain. This review reports on the most recent findings in PDT, with emphasis on cutaneous precancerous lesions.

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.

Reflectance confocal microscopy in the diagnosis of pigmented macules of the face: differential diagnosis and margin definition

Here we review the state-of-the-art of RCM morphologic descriptors, standardized terminology, and diagnostic algorithms for the assessment of pigmented macules of the face, for their correct diagnosis and management.

Confocal Microscopy and Lentigo Maligna: An in vivo Pilot Study for the Assessment of Response to Imiquimod Therapy

Background: Reflectance confocal microscopy (RCM) is a noninvasive technique that provides real-time in vivo images of the epidermal layer. Imiquimod has been recommended as an alternative treatment in lentigo maligna (LM) when surgical excision is not the treatment of choice. In the present study we compare the results of in vivo RCM to the histopathological examination before and after treatment of LM with topical imiquimod. Methods: Thirty-four patients with confirmed LM were included. Imiquimod 5% was applied until a weeping erosion appeared in the LM-affected skin. Evaluation was performed by clinical examination, dermatoscopy, histopathology and RCM. Results: During the follow-up, 27 of 34 patients (79.42%) demonstrated a total tumor clearance by imiquimod treatment. In the treated area, a significant decrease of atypical cells was detected using RCM (p < 0.0001). Furthermore, a significant positive correlation in the detected atypical cells was shown using confocal microscopy and histology (p = 0.0001, r = 0.7335, respectively). Conclusion: In patients not suitable for surgical intervention imiquimod treatment is an appropriate treatment alternative. Thereby, in vivo RCM was demonstrated to be an excellent examining device, which not only allows diagnosis of LM, but also therapy and follow-up examinations. An important benefit of RCM, in contrast to conventional histopathology, is the simple handling with in vivo examination of epidermal skin without any pain for the patient.

Management of clinical and subclinical actinic keratoses with histological and immunohistochemical assessments by confocal microscopy

Reflectance confocal microscopy has been used to monitor treatment efficacy in non-melanoma skin cancer, but few studies have compared different therapies using the same confocal criteria. We compare a single score designed in previous study to evaluate confocal, histological, and immunohistochemical results obtained before and after two treatments of actinic keratosis (AK) and in field cancerisation area. Thirty volunteer male patients, aged >50-year old, with at least three clinically visible AKs on the bald scalp, were included in this study: 15 patients were submitted to 3% diclofenac therapy and 15 to 5% fluorouracil therapy. Confocal imaging was performed on a 5 × 5 cm skin area. In five patients of each group we performed cutaneous biopsies. Scaling, upper nucleated cells, and inflammatory cells showed a higher percentage reduction in field cancerisation, especially in diclofenac treatment group, while in AK inflammatory cells showed a greater percentage reduction in 5-fluorouracil treatment group. Both therapies are efficacious, but their effectiveness is different on the single parameters of the confocal, histology, immunohistochemically.

Photodynamic therapy as an alternative treatment for mycosis fungoides: a systemic review and meta-analysis

INTRODUCTION

Mycosis fungoides is the most common cutaneous T cell lymphoma. Selection of appropriate treatment for mycosis fungoides (MF) is based on prognostic factors and overall clinical stage at diagnosis. In the past decade, clinical success has been reported using photodynamic therapy (PDT) as an alternative target-specific therapy to treat mycosis fungoides. This review aimed to summarize the current advances in management of mycosis fungoides by administration of photodynamic therapy.

EVIDENCE ACQUISITION

Twenty-four articles, published between 1994 and 2017, were reviewed to assess the efficacy of PDT for MF.

EVIDENCE SYNTHESIS

Methyl-aminolevulinic acid has increased lipophilic properties; red light at around 630 nm achieves deepest and best tissue penetration. However, the total number of PDT sessions depends on the clinical response.

CONCLUSIONS

Further multicenter clinical studies are warranted to assess the cost-effectiveness of PDT.

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.