Biomedical Photonics (Jan 2016)
COMPARATIVE STUDIES OF EFFICACY OF PHOTODYNAMIC THERAPY AND CRYOTHERAPY FOR TREATMENT OF ACTINIC KERATOSIS
Abstract
The results of a study on the effectiveness of photodynamic therapy with a photosensitizer fotoditazin and cryotherapy for actinic keratosis are represented in the article. The study included 80 patients with 215 lesions, among them erythematous form of actinic keratosis was diagnosed in 151 (70.2%) cases, hyperkeratotic form – in 46 (21.4%) cases, a pigmented form – in 12 (5.6%) and an atypical variant of the disease – in 6 (2.8%) cases. According to histological type the distribution of tumor was as follows: 19 (54.3%) cases were diagnosed as hypertrophic type, 6 (17.1%) – atrophic, 8 (22.9%) – bowenoid and 2 (5.7% ) – pigmented type. Patients from the study group received one session of photodynamic therapy using laser unit "LAMI" (662 nm) after 2 hours of application of fotoditazin 0.5% gel at dose of 0,2-0,3 ml per 1 cm2 of actinic keratosis focus with the following parameters: the energy density of the laser radiation – 200 J/cm2, power density – 0.14–0.48 W/cm2. In the control group patients underwent cryotherapy with liquid nitrogen with an exposure of 30-60 sec. The comparative analysis of the immediate results showed a tendency for the efficacy of photodynamic therapy to increase (the rate of complete regression was 92.5%) compared with cryotherapy (85.0%) (p>0,05). There were also a tendency for long-term results after photodynamic therapy to improve: three-year recurrence-free survival was 94.6% and 88.2%, respectively. For the photodynamic therapy there were significantly fewer adverse reactions, the epithelization time in lesions was significantly shorter. Compared with cryotherapy the photodynamic therapy provided significantly better cosmetic results (p <0.01), and can be used for out-patient treatment of patients with actinic keratosis.><0.01) and can be used for out-patient treatment of patients with actinic keratosis.
