Photodynamic therapy for large or multiple patches of Bowen disease and basal cell carcinoma

Photodynamic therapy (PDT) using topical delta-aminolevulinic acid (delta-ALA) is an effective treatment for Bowen disease and certain basal cell carcinomas (BCCs), but its place in clinical practice remains to be established. Patients with large and/or multiple lesions of Bowen disease or BCC can represent a considerable therapeutic challenge. We suggest that delta-ALA PDT may be of particular benefit in such patients.

In an open study, 35 (88%) of 40 large patches of Bowen disease, all with a maximum diameter greater than 20 mm, cleared following 1 to 3 treatments of delta-ALA PDT, although 4 patches recurred within 12 months. delta-Aminolevulinic acid PDT was also used to treat 40 large BCCs, with an identical 88% initial clearance (after 1-3 treatments), with 4 recurrences within 34 months (range, 12-60 months). In 10 further patients with multiple (> or =3) patches of Bowen disease, 44 (98%) of 45 patches cleared following delta-ALA PDT, although 4 lesions recurred over 12 months. In 3 patients with multiple BCCs, PDT cleared 52 (90%) of 58 lesions, with 2 recurrences during 41 months (range, 12-52 months). Treatments were well tolerated, with only 5 patients with solitary large lesions requiring local anesthesia.

delta-Aminolevulinic acid PDT is an effective tissue-sparing modality achieving good cosmesis. We propose that delta-ALA PDT be considered as a first-line therapy for large and/or multiple areas of Bowen disease and superficial BCCs.