Evaluation of diagnostic criteria of actinic keratosis through reflectance confocal microscopy

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.

Efficacy and safety of microneedling, fractional CO2 laser, and cryotherapy combined with 5-aminolevulinic acid photodynamic therapy in the treatment of actinic keratosis: A multicenter prospective randomized controlled study

BACKGROUND

Photodynamic therapy (PDT) for actinic keratosis (AK) is limited by the depth of treatment. Microneedling or fractional CO2 laser can facilitate the penetration of photosensitizer, while cryotherapy can treat deeper tissues but is not suitable for field cancerization.

OBJECTIVE

To investigate the efficacy of microneedling, fractional CO2 laser, and cryotherapy in combination with PDT for AK.

METHODS

Patients with AK were randomized into 4 groups, including group A with microneedling + PDT, group B with fractional CO2 laser + PDT, group C with cryotherapy + PDT, and group D with PDT. After 12 weeks, the clinical, dermoscopic, and reflectance confocal microscopy (RCM) outcomes were assessed.

RESULTS

A total of 129 patients were included in this study, with 31, 30, 35, and 31 patients in each group, yielding clinical response rates of 90.3%, 93.3%, 97.1%, and 74.2%, respectively (P=0.026). The RCM response rates were 71.0%, 80.0%, 85.7%, and 54.8%, respectively (P=0.030). The dermoscopic response rates were 77.4%, 83.3%, 88.6%, and 60.0%, respectively (P=0.039). Group C showed the best efficacy in terms of clinical, dermoscopic, and RCM outcomes.

CONCLUSIONS

All three treatments improved the efficacy of PDT and were well tolerated, with cryotherapy + PDT showing the best efficacy.

The differential diagnosis of lichenoid keratosis and seborrheic keratosis with reflectance confocal microscopy: a preliminary study

BACKGROUNDS AND OBJECTIVES

Lichenoid keratosis (LK, or lichen planus-like keratosis, LPLK) and seborrheic keratosis (SK) present as similar benign keratotic lesions on cosmetically sensitive area, but require different therapies. Both lesions can be easily differentiated based on histological evaluation of biopsy materials. However, the biopsies may cause scarring and result in hyper-pigmentation, which reduces the compliance of the patients to be treated. In this study, we investigated the role of reflectance confocal microscopy (RCM) in the non-invasive differential diagnosis of LK and SK.

PATIENTS AND METHODS

Cases with facial brown patches or plaques suspicious of SK were enrolled in the study. After written informed consent was obtained, the lesions were photographed, imaged by RCM, and then biopsied. The RCM findings were analyzed and correlated with histology results. Evaluation of the RCM pictures and confirmation with histological results were conducted by two independent dermatologists.

RESULTS

In total, 10 cases were enrolled in the study. The main characteristics of LK lesions observed by RCM were the disarray of the dermal-epidermal junction (DEJ), and marked inflammatory infiltrates in the superficial dermis; while prominent cerebriform pattern, or elongated cords with bulbous projections without significant inflammation reaction, were the features of SK. Among the 10 cases, clinically suspicious of facial SK, 4 were determined as LK, 6 as SK by RCM imaging, and all the RCM findings were confirmed by histological results.

CONCLUSIONS

The RCM features of LK and SK have significant difference, highlighting the important role of RCM in the differential diagnosis of LK and SK, avoiding biopsies and allowing safe treatments.

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.