Cervical intraepithelial neoplasia (CIN) is the precursor of invasive cervical cancer. Previous studies indicated that
photodynamic therapy (PDT) represents an effective treatment modality in CIN. In 28 patients with CIN 1 - 3, 1 - 2
cycles of PDT were conducted using hexaminolevulinate (HAL) or methylaminolevulinate (MAL) and a special light
delivery system. After 6 months, biopsies were obtained to assess response. The overall response rate for complete or
partial response was 65%. Photodynamic therapy using new ALA esters is effective and may offer unique advantages in
the therapy of CIN.