Photodynamic therapy of vulvar intraepithelial neoplasia using 5-aminolevulinic acid

Photodynamic (PDT) therapy is a relatively new technique with unique properties that make it attractive for the local treatment of superficial epithelial disorders. The objective of this study was to investigate the clinical response of PDT with the photosensitizing agent 5-aminolevulinic acid (5-ALA) in patients with vulvar intraepithelial neoplasia (VIN) grades 1 to 3. Twenty-five patients with 111 lesions of VIN 1-3 were topically sensitized with 10 ml of a 20% solution of 5-ALA and treated with 57 cycles of laser light at 635 nm (100 J/cm(2)). Seventy (64%) of the 111 VIN lesions regressed after various PDT cycles. A complete response was achieved in 13 patients (52%) with 27 lesions. All patients with VIN 1 and mono- and bifocal VIN 2-3 showed complete clearance. However, a complete response could be achieved in only 4 (27%) of 15 women with multifocal VIN 2-3, whereas a partial response was noted in 9 of these patients with a total of 70 lesions, out of which 44 (63%) lesions disappeared. No response was seen in 2 patients with multifocal VIN 3. Histological assessment of the fluorescence-directed biopsies revealed that increased pigmentation and hyperkeratosis of the lesions were associated with low response rates. PDT using 5-ALA represents an alternative treatment modality for VIN which is easy to perform and has the advantage of minimal tissue destruction, low side effects and excellent cosmetic results. However, multifocal VIN disease with pigmented and hyperkeratinic lesions remains difficult to treat.