[Photodynamic diagnosis of vulvar precancerous conditions and invasive cancers using 5-aminolevulinic acid].

BACKGROUND

Photodynamic therapy (PDT), in particular Photodynamic diagnosis (PDD) is a modern, non-invasive technique using photosensitizer like 5-aminolevulinic acid (5-ALA) in detection of the vulvar diseases. Photodynamic therapy gives the possibilities to differentiate inflammatory diseases from precancerous lesions and invasive vulvar cancer.

OBJECTIVE

To assess accuracy of the PDD in detection, localisation and differentiation of precancerous diseases and invasive cancer of the vulva.

MATERIAL AND

METHODS

This study included 107 patients with vulvar disorders, 30 patients with VIN I, 31 patients with VIN II, and 46 patients with VIN III and vulvar carcinoma. All women underwent a standard gynaecologic examination. 5-ALA was topically applied to the vulva. After 180-360 minutes the vulvar skin was illuminated by a short--are xenon lamp at 380-440 nm and an output of 200 mW (D-Light; Karl storz). A filter to select the emitted wavelength range 630-670 nm was used in order to achieve differentiation's of the fluorescence--positive and negative areas. After the PDD, biopsies were taken from patients with multifocal VIN lesions. Macroscopic appearance, fluorescence pattern in scale of three degrees (zero, +, ++) and histology of the lesions were compared.

RESULTS

The sensitivity, specificity, positive and negative predictive value for the detection of VIN I were 85.7%, 81.2%, 80.0%, 86.6% respectively, for VIN II there were 93.3%, 93.7%, 93.3% and 93.7%, and for VIN III and invasive vulvar cancer there were 96.3%, 94.7%, 96.3% and 94.7% respectively. The sensitivity, specificity, positive and negative predictive value for the detection of all VIN and invasive vulvar cancer common were 92.9%, 90.2%, 91.2%, 92.0 respectively.

CONCLUSION

The Photodynamic therapy becomes a valuable, non-invasive diagnostic tool that lowers the amount of false negative diagnosis in cases of VIN and vulvar cancer.