Fractional laser-mediated photodynamic therapy of high-risk basal cell carcinomas--a randomized clinical trial

Abstract

Background: Photodynamic therapy (PDT) is approved for selected nodular basal cell carcinomas (nBCC) but efficacy is reduced for large and thick tumours. Ablative fractional lasers (AFXL) facilitate uptake of methyl aminolaevulinate (MAL) and may thus improve PDT outcome.

Objectives: To evaluate efficacy and safety of AFXL-mediated PDT (AFXL-PDT) compared with conventional PDT of high-risk nBCC.

Methods: Patients with histologically verified facial nBCC (n = 32) defined as high-risk tumours were included; diameter > 15 mm, tumours located in high-risk zones, or on severely sun-damaged skin. Tumours were debulked and patients randomized to either AFXL-PDT (n = 16) or PDT (n = 16). Fractional CO2 laser treatment was applied at 5% density and 1000 μm (80 mJ) ablation depth. MAL was applied under occlusion for 3 h and illuminated with a 633-nm light-emitting diode source, 37 J cm(-2) . Clinical assessments were performed at 3, 6, 9 and 12 months and biopsies were taken at 12 months.

Results: Clinical cure rates at 3 months were 100% (16 of 16 AFXL-PDT) and 88% (14 of 16 PDT, P = 0·484). Recurrences tended to occur later and in lower numbers after AFXL-PDT at 6, 9 and 12 months (6%, 19%, 19%) than PDT (25%, 38%, 44%) (P = 0·114). Histology at 12 months documented equal tumour clearance after AFXL-PDT (63%, 10 of 16) and PDT (56%, 9 of 16). Cosmetic outcomes were highly satisfactory after both treatments (P > 0·090).

Conclusions: Long-term efficacy was similar after PDT and AFXL-PDT with a trend for a favourable short-term cure rate after AFXL-PDT. AFXL-PDT needs further refinement for nBCC and at present is not recommended over PDT.