Safety and Efficacy of Aminolevulinic Acid Hydrochloride Topical Gel, 10%, with Red Light in the Treatment of Facial Cutaneous Squamous Cell Carcinoma In Situ.

BACKGROUND

Cutaneous squamous cell carcinoma in situ (isSCC) is a common skin cancer often arising on the face. Standard care involves excision or destruction, but less invasive therapies are becoming increasingly explored. Aminolevulinic acid photodynamic therapy (ALA-PDT) with red light has shown potential for treating isSCC. This study assesses the safety, tolerability, and efficacy of ALA-PDT with red light for facial isSCC.

METHODS

Twenty patients with biopsy-confirmed facial isSCC (0.4-1.3cm) were treated. Lesions were prepared with a 4×4 gauze, followed by application of ALA gel 10% with 3-hour incubation. Red light therapy (13 minutes and 30 seconds; 37J/cm²) was then administered. Patients received two sessions 28±3 days apart. Eight weeks after the second treatment, lesions were excised for histopathologic analysis. The primary endpoint was complete histologic clearance, with clinical clearance as a secondary endpoint. Safety was evaluated through adverse events (AEs), local skin reactions (LSRs), and treatment-site pain.

RESULTS

All 20 patients completed the study. Complete histologic clearance was achieved, and complete clinical clearance was observed in 100% (20 of 20) patients. No treatment-related AEs occurred. One unrelated case of contact dermatitis was reported. The most common LSR was moderate erythema, peaking after treatment and resolving over time. Mild scaling was also observed with similar resolution. Median posttreatment pain scores were 0 (range: 0-3) after ALA application and 3.5 (range: 0-10) after red light therapy.

CONCLUSION

ALA-PDT with 10% gel and red light demonstrated excellent efficacy, safety, and tolerability, supporting its role as a promising noninvasive treatment for facial isSCC.