Daylight-Photodynamic Therapy for the Treatment of Actinic Keratosis in Different Seasons

BACKGROUND: non-melanoma skin cancer (NMSC) is the most common malignancy, whose public health significance is often unrecognized. Its incidence continues to grow at an alarming rate, becoming an occupational disease. Available treatments alternative to surgery include: photodynamic therapy, electrochemiotherapy, cryotherapy, ablative lasers, 5-fluorouracil, imiquimod, ingenol mebutate, and diclofenac. Each of these options has its advantages and disadvantages. Photodynamic therapy (PDT), using topically applied photosensitizer precursors such as methylaminolaevulinate (MAL), is a useful nonsurgical treatment, well accepted by patients, but the main limitation is pain. Recently, in order to overcome this limit, visible light irradiation photherapy was considered.<br> AIM: we report our experience comparing conventional PDT (406 patients) with daylight-mediated PDT (D-PDT) 240 patients with multiple actinic keratoses (AK), afferent to our photodynamic outpatients clinic from September 2013 to June 2014.<br> MATERIALS AND METHODS: to establish predictors for the clinical response to conventional PDT and daylight PDT (DPDT), a retrospective study on 646 patients was performed. The following parameters have been evaluated: sex, age, anatomic site of the primary tumor and local skin reactions. We used the Spearmen's coefficient between the clinical response and the predictors analyzed; while Odds Ratio (OR) was performed to evaluate general clinical response and local skin reaction between PDT and D-PDT patients. Subsequently, we performed a sub-analysis, focusing to the anatomical sites, and we subdivided anatomical sites in face and scalp, nose, trunk, and extremities.<br> RESULTS: a total of 406 patients treated with PDT and 240 patients treated with D-PDT, were enrolled in the current report. The median age was 71 years in PDT and 73 years in D-PDT. The mean clinical response in PDT was of 74.4% and 95% in D-PDT. Performing OR between PDT and D-PDT, according to the clinical response, we found a better behavior in patients treated with D-PDT (<em>P</em> &lt; 0.03); the same significance was maintained according to the presence or absence of local skin reaction (<em>P</em> &lt; 0.0002). Using no parametric Spearman's Coefficient test among predictive factors and the therapeutical response we found that D-PDT showed a better clinical response in patients with AK size ≥0.6 mm (<em>P</em> &lt; 0.03), while this evidence was not present in PDT. The nose remained in both PDT and DPDT the main anatomical site with a better clinical response to the treatment.<br> CONCLUSION: Since efficacy of D-PDT is comparable or superior to conventional type, but is simpler and better appreciated by patients, in our opinion it may be used routinely to treat sun exposed multiple AKs especially in sun damaged skin also for aesthetic purposes.<br><br> <em>J Drugs Dermatol</em>. 2015;14(11):1349-1353.