SELECTIVITY OF PROTOPORPHYRIN-IX FLUORESCENCE FOR CONDYLOMATA AFTER TOPICAL APPLICATION OF 5-AMINOLEVULINIC ACID - IMPLICATIONS FOR PHOTODYNAMIC TREATMENT

To examine the potential of using photodynamic therapy (PDT) in condyl omata, we studied the distribution and kinetics of protoporphyrin IX ( PpIX) formation in condylomata acuminata and adjacent normal skin afte r topical application of 5-aminolaevulinic acid (ALA), PpIX fluorescen ce spectra were measured hourly in vivo after ALA application, After g rass fluorescence imaging, the lesions were biopsied, and fluorescence microscopy was performed, All three PpIX fluorescence detection modal ities suggested selectivity of PpIX formation in condylomata after top ical ALA application, In 17 of 25 condylomata, there was significantly greater fluorescence compared with adjacent normal skin, The greatest lesional to normal skin fluorescence ratios occurred after 2 h, The m ost likely mechanism for increased lesional PpIX formation in condylom ata is enhanced stratum corneum permeability. Based on our results, AL A/PDT is a potential field therapy for condylomata, PpIX fluorescence imaging after ALA application may also be useful for localizing condyl omata prior to treatment.