Photodynamic therapy light’: An enhanced treatment protocol for actinic keratoses with minimal pain and optimal clinical outcome by combining laser-assisted low irradiance PDT with shortened daylight PDT

• Published in: Photodiagnosis and photodynamic therapy 2025-02, Vol.51, p.104372, Article 104372
• Main Authors: Braun, Martin T., Tredici, Kelly Del, Wölling, Anna, Wiest, Luitgard
• Format: Article
• Language: English
• Subjects: Actinic keratoses; Pain during illumination; PDT; PDT light; Photodynamic therapy; Phototoxic side-effects
• ISSN: 1572-1000; 1873-1597; 1873-1597
• DOI: 10.1016/j.pdpdt.2024.104372

•‘PDT light’ is nearly painless with an average visual-analogue scale score of 1.19•It achieves equal clinical outcomes and fewer side-effects than cPDT and even DLPDT•Advantages are reduced illumination time, shorter clinic stays, and better compliance•With ‘PDT light’, premature withdrawal from therapy can be minimized. Between 2003 and 2016, 546 patients in our clinic discontinued outpatient treatment for actinic keratoses (AKs) using conventional photodynamic therapy (PDT) because of intolerable pain, thereby necessitating the use of a less painful procedure. Therefore, we developed a novel off-label PDT protocol: ‘PDT light’. Laser-assisted low irradiance PDT (li-PDT) was performed beginning in 2014. The dosage was gradually lowered to 8-12 J/cm² in 2018, so that we achieved considerable pain reduction while maintaining comparable therapeutic efficacy. A further considerable reduction in pain was achieved from 2018 onwards by combining the advantages of li-PDT with daylight PDT (DLPDT), thereby resulting in 2018 in the new technique ‘PDT light’. Patients with AK Olsen grades 1 or 2 and field cancerization initially received a mild-fractionated CO2 laser pretreatment prior to MAL-incubation (methyl aminolaevulinate, Metvix ®) under occlusion for 1.5-3 h. Then, patients were illuminated on average for 1.02 min with the Aktilite-LED and, after application of an UV-screen on the illuminated area, sent out into daylight for 1 h. Between March and November 2019, we successfully treated 152 cases using the enhanced ‘PDT light’ procedure, with 137 cases achieving at follow-up 1 (on average after 8.14 months) good-to-excellent clearance rates (CLA and CLB together 90%) and minimal adverse effects. The novel ‘PDT light’ protocol proved to be an excellent and nearly painless method with an average visual-analogue scale (VAS) score of 1.19. Additional advantages included reduced illumination time, shorter outpatient stays in the clinic, fewer adverse effects, and better patient compliance than with DLPDT alone.