P129 A prospective comparative audit of outcomes in patients with basal cell carcinoma receiving 10 600-nm carbon dioxide laser-assisted photodynamic therapy with either methyl aminolaevulinate or 5-aminolaevulinic acid as a photosensitizer

Abstract Photodynamic therapy (PDT) is a well-established nonsurgical management option for low-risk basal cell carcinomas (BCCs). This study compares the efficacy of two photosensitizing agents: methyl aminolaevulinate (MAL) and 5-aminolaevulinic acid (ALA), when used for patients undergoing 10 600-nm carbon dioxide laser-assisted photodynamic therapy. We included all patients with BCC receiving fully ablative laser-assisted PDT at a tertiary centre between November 2021 and November 2024. Lesions were first ablated with a 10 600-nm carbon dioxide laser (SmartXide Touch, DEKA Laser, Calenzano, Italy) under local anaesthetic. The photosensitizer was applied topically according to availability, and incubated for 3 h. The photosensitizer was either MAL 160 mg g−1 cream (Metvix; Galderma, Lausanne, Switzerland) or 5-ALA 78 mg g−1 gel (Ameluz; Biofrontera, Leverkusen, Germany). Photoactivation was by pulsed-dye laser (Cynergy; Cynosure, Westford, MA, USA) or intense pulsed light (Excelight, Lynton, UK). In total 132 lesions were included from 33 patients. Overall, 54.5% were treated with the photosensitizer MAL and 45.5% were treated with ALA. The rolling recurrence rate for all lesions treated with MAL was 2.8%, and with ALA 1.7%. The 2-year recurrence rate for MAL was 5.7% and for ALA 0.0%. Complication rates were low and were 1.4% for MAL and 1.7% for ALA. Cosmetic outcomes were good in both groups, with mean Vancouver Scar Scores of 3.1% and 3.9% for MAL and ALA, respectively. This study concludes that ALA-PDT has a lower overall and 2-year recurrence rate than MAL-PDT. The rate of complications was lower for MAL-PDT than for ALA-PDT, and the cosmetic outcomes for MAL-PDT were slightly better than for ALA-PDT when assessed using mean Vancouver Scar Scores.