COMPARISON OF PHOTODYNAMIC THERAPY WITH CRYOTHERAPY IN THE TREATMENT OF BOWENS-DISEASE

The efficacy and suitability of photodynamic therapy (PDT) was compare d with that of cryotherapy in the treatment of 40 lesions of Bowen's d isease, Lesions were randomized to receive either cryotherapy with liq uid nitrogen, or PDT using a portable desktop lamp incorporating a 300 W xenon short are discharge source, A porphyrin precursor, 5-aminolae vulinic acid (5-ALA), was applied topically 4 h before irradiation in the PDT group, Each lesion received 125 J/cm(2) at a fluence rate of 7 0 mW/cm(2), All patients were reviewed at 2-monthly intervals and trea tments repeated if required. Cryotherapy produced clearance in 10 of 2 0 lesions after one treatment, the remaining 10 lesions requiring two or three treatment applications, PDT resulted in clearance of 15 of 20 lesions after one treatment and of the remaining five lesions after a second treatment. The probability that a lesion cleared after one tre atment was greater with PDT than cryotherapy (P < 0.01), Cryotherapy w as associated with ulceration (five of 20), infection (two of 20) and recurrent disease (two of 20); no such complications occurred followin g PDT, PDT using a non-laser light source and topical 5-ALA appears to be at least as effective as cryotherapy in the treatment of Bowen's d isease with fewer adverse effects.