The present study shows that, when treated with both MAL-PDT and cryotherapy, subjects significantly prefer MAL-PDT treatment for AK. MAL-PDT is an attractive treatment option for AK, with comparable efficacy and superior cosmetic outcomes compared with double freeze-thaw cryotherapy.

Background: Photodynamic therapy (PDT) involves the activation of a photosensitiser by visible light to produce activated oxygen species within target cells, resulting in their destruction. Evidence-based guidelines support the efficacy of PDT using topical 5-aminolaevulinic acid (ALA-PDT) in actinic keratoses, Bowen's disease and basal cell carcinoma (BCC). Efficacy for nodular BCC appears inferior to that for superficial BCC unless prior debulking or repeat treatments are performed.The aim of this study was to assess the safety and efficacy of adding a novel iron chelating agent, CP94 to topical ALA, to increase the accumulation of the photosensitiser in the tumour.Observations: Enhanced PDT using 40% CP94 resulted in significantly greater clearance rates in nodular BCC than with ALA-PDT alone, in our protocol of single treatment PDT with no lesion preparation. Conclusion:The results of this study demonstrate the safe and effective use of an enhanced ALA-PDT protocol for nodular BCC using CP94, with no adverse reactions to this modification. This is the first time this formulation has been used in patients.This formulation is now the focus of further study.

Purpose:Methyl-aminolevulinate (MAL) photodynamic therapy (PDT) is a cancer therapy that combines the selective accumulation of a photosensitizer in tumor tissue with visible light (and tissue oxygen) to produce reactive oxygen species. This results in cellular damage and ablation of tumor tissue. Combining iron chelators with MAL has the potential to increase the accumulation of the photosensitizer protoporphyrin IX (PpIX) by reducing its bioconversion to heme. This paper investigates this method of enhancement both in vitro and for the first time clinically for the treatment of nodular basal cell carcinoma (BCC). Methods:Enhancement of MAL-induced PpIX accumulation by the iron chelator CP94 was quantified fluorometrically in human cultured cells (including three dermatological cell types). An open, dose-escalating, pilot study was then conducted in patients with nodular BCC, to determine the safety of this pharmacological modification. Results:Large enhancements in PpIX accumulation were observed in the cultured cells when coincubated with the iron chelator CP94. Clinically the addition of CP94 was found to be feasible and safe. In addition greater reductions in tumor depth were observed in the CP94 coincubated tumors. Conclusion:Iron chelation by CP94 is an effective enhancer of MAL-induced PpIX accumulation in vitro.

Acral PDT 2 What's already known about this topic?Methyl-aminolevulinate photodynamic therapy (MAL-PDT) is known to be successful in the treatment of non-melanoma skin cancers (NMSC) and pre-cancerous lesions.However studies have demonstrated that efficacy of this treatment is reduced when these skin lesions are located on the body's extremities at acral sites. What does this study add?This study provides further evidence of the disparity between the response of dermatological skin lesions located at acral and non-acral sites to MAL-PDT treatment. For the first time this study monitors the changes in PpIX fluorescence during MAL-PDT treatment of (pre)cancerous skin lesions located within acral and non-acral sites. Comparison of changes in PpIX fluorescence within lesions at these sites furthers our understanding of the poorer response witnessed at acral sites. Acral PDT 3 AbstractBackground Topical photodynamic therapy is successful in the treatment of non-

Background and Objective: The relationship between protoporphyrin IX (PpIX)