A New Light-Emitting, Fabric-Based Device for Photodynamic Therapy of Actinic Keratosis: Protocol for a Randomized, Controlled, Multicenter, Intra-Individual, Phase II Noninferiority Study (the Phosistos Study)

Advanced Light Source Technologies for Photodynamic Therapy of Skin Cancer Lesions

Photodynamic therapy (PDT) is an increasingly popular dermatological treatment not only used for life-threatening skin conditions and other tumors but also for cosmetic purposes. PDT has negligible effects on underlying functional structures, enabling tissue regeneration feasibility. PDT uses a photosensitizer (PS) and visible light to create cytotoxic reactive oxygen species, which can damage cellular organelles and trigger cell death. The foundations of modern photodynamic therapy began in the late 19th and early 20th centuries, and in recent times, it has gained more attention due to the development of new sources and PSs. This review focuses on the latest advancements in light technology for PDT in treating skin cancer lesions. It discusses recent research and developments in light-emitting technologies, their potential benefits and drawbacks, and their implications for clinical practice. Finally, this review summarizes key findings and discusses their implications for the use of PDT in skin cancer treatment, highlighting the limitations of current approaches and providing insights into future research directions to improve both the efficacy and safety of PDT. This review aims to provide a comprehensive understanding of PDT for skin cancer treatment, covering various aspects ranging from the underlying mechanisms to the latest technological advancements in the field.

Equivalent efficacy of indoor daylight and lamp‐based 5‐aminolevulinic acid photodynamic therapy for treatment of actinic keratosis

Background

Photodynamic therapy (PDT) is widely used as a treatment for actinic keratoses (AK), with new sunlight-based regimens proposed as alternatives to lamp-based treatments. Prescribing indoor daylight activation could help address the seasonal temperature, clinical supervision, and access variability associated with outdoor treatments.

Objective

To compare the AK lesion clearance efficacy of indoor daylight PDT treatment (30 min of 5-aminolevulinic acid (ALA) pre-incubation, followed by 2 h of indoor sunlight) versus a lamp-based PDT treatment (30 min of ALA preincubation, followed by 10 min of red light).

Methods

A prospective clinical trial was conducted with 41 patients. Topical 10% ALA was applied to the entire treatment site (face, forehead, scalp). Patients were assigned to either the lamp-based or indoor daylight treatment. Actinic keratosis lesion counts were determined by clinical examination and recorded for pre-treatment, 1-month, and 6-month follow-up visits.

Results

There was no statistical difference in the efficacy of AK lesion clearance between the red-lamp (1-month clearance = 57 ± 17%, 6-month clearance = 57 ± 20%) and indoor daylight treatment (1-month clearance = 61 ± 19%, 6-month clearance = 67 ± 20%). A 95% confidence interval of the difference of the means was measured between -4.4% and 13.4% for 1-month, and -2.2% and +23.6% for 6-month timepoints when comparing the indoor daylight to the red-lamp treatment, with a priori interval of equivalence of ±20%.

Limitations

Ensuring an equivalent dose between the indoor and lamp treatment cohorts limited randomisation since it required performing indoor daylight treatments only during sunny days.

Conclusion

Indoor-daylight PDT provided equivalent AK treatment efficacy to a lamp-based regimen while overcoming temperature limitations and UV-block sunscreen issues associated with outdoor sunlight treatments in the winter.

Clinical trial registration

Clinicaltrials.gov listing: NCT03805737.

Photodynamic therapy with light emitting fabrics: a review

Photodynamic therapy is a powerful tool in the localized and selective treatment of dermatologic diseases, such as actinic keratosis, acne vulgaris, Bowen's disease and basal cell carcinoma. The success of photodynamic therapy is mainly attributed to the development of flexible light sources for homogenous and reproducible illumination during clinical studies. The essential requirement for this therapy includes, a suitable photosensitizer, presence of oxygen and a light of specific wavelength and intensity. The use of light emitting fabric comprising of optical fibers provides an exciting and an efficient way to transfer light directly to the skin uniformly on the infected body parts. As the optical fibers can transmit light from 400 to 1200 nm it is possible to combine light emitting fabric with laser sources for medical applications. This review focusses on the challenges and recent developments in the use of light emitting fabric for photodynamic therapy in clinical studies and its future perspectives.

Photodynamic Therapy Using a New Painless Light-Emitting Fabrics Device in the Treatment of Extramammary Paget Disease of the Vulva (the PAGETEX Study): Protocol for an Interventional Efficacy and Safety Trial

Background

Extramammary Paget disease of the vulva (EMPV) is a rare skin disorder commonly seen in postmenopausal Caucasian females that appears clinically as red, eczematous, pruriginous, and sometimes painful lesions. Although most cases are noninvasive, EMPV may be associated with an underlying or distant adenocarcinoma. EMPV has a chronic and relapsing course. The reference treatment is based on local surgical excision with negative margins. However, disease frequently extends far from the visible lesion, and surgical margins are frequently positive. Topical photodynamic therapy (PDT) is an established treatment modality for various dermatooncologic conditions. For example, red light irradiation with the Aktilite CL 128 and Metvixia (Galderma SA) as a photosensitizing molecule is a conventional protocol approved and widely used in Europe for PDT treatment of actinic keratosis, but this treatment is not yet widely used for EMPV because it has never clearly been demonstrated and is very painful.

Objective

The aim of the study is to investigate the efficacy and safety relating to the medical device PAGETEX as a new painless PDT device using Metvixia in the treatment of vulvar Paget disease. The primary end point is the disease control rate at 3 months in 30% of the patients included, defined as stability, partial response, or total response, considering the extent of the lesion. Secondary end points are the disease control rate at 6 months, patient quality of life, level of pain experienced by the patient at each PDT session, severity of erythema, presence of protoporphyrin IX in Paget cells after each PDT session, and overall satisfaction level of the patient.

Methods

The trial is an interventional, exploratory, simple group, nonrandomized, and single center (Lille University Hospital) study. Twenty-four patients will be included according to Simon’s optimal plan. Therapeutic procedure is based on a cycle of two PDT sessions with the PAGETEX medical device at 15-day intervals (Metvixia incubation during 30 minutes and 635 nm red light illumination with a low irradiance for 2 hours and 30 minutes for a total fluence of 12 J/cm²). At the assessment session, 3 months after inclusion, if the control of the disease is partial or null, the patient will complete another cycle of two PDT sessions. A final evaluation will be performed in all patients at 6 months. Analyses will be performed using SAS version 9.4 software (SAS Institute Inc). The characteristics of the patients at baseline will be described; qualitative variables will be described by numbers and percentages, and quantitative variables will be described either by the mean and standard deviation for Gaussian distribution or by the median and interquartile range (ie, 25th and 75th percentiles). The normality of the distributions will be tested by a Shapiro-Wilk test and checked graphically by histograms.

Results

First patient was included in September 2019 and clinical investigations are planned until August 2022. The final results of this study are expected to be available in January 2023.

Conclusions

This clinical trial aims to evaluate the efficacy and safety of a new PDT protocol for the treatment of EMPV. The PAGETEX device could become the treatment of choice if it is effective, painless, and easy to implement and use in hospitals.

Trial Registration

ClinicalTrials.gov NCT03713203; https://clinicaltrials.gov/ct2/show/NCT03713203

International Registered Report Identifier (IRRID)

PRR1-10.2196/15026