Evaluating the Noninferiority of a New Photodynamic Therapy (Flexitheralight) Compared With Conventional Treatment for Actinic Keratosis: Protocol for a Phase 2 Study.

Background: Actinic keratosis (AK) is characterized by preinvasive, cancerous lesions on sun-exposed skin that negatively affect patient quality of life and may progress to invasive squamous cell carcinoma (SCC). If untreated, AK may either regress or progress to SCC, with significant morbidity and possible lethal outcomes. The most commonly used treatments for AK are cryotherapy, topical chemotherapy and, more recently, photodynamic therapy (PDT).

Can daylight-PDT be performed indoor?

Natural DayLight-mediated PhotoDynamic Therapy (NDL-PDT) is an efficacious treatment option for thin actinic keratosis that offers advantages over conventional PDT in terms of tolerability and cost. It is now accepted that the minimum criteria required for effective NDL-PDT is a dose of 4 J/cm² with a treatment time of 2 hours and a minimum temperature of 10 °C, corresponding to a minimum illuminance of 11,000 lux. This value is easily achievable: 20,000 lux can be obtained during a typical overcast day at midday.