Evaluation of the treatment costs and duration of topical treatments for multiple actinic keratosis based on the area of the cancerization field and not on the number of lesions

Background: The cost of topical treatments for actinic keratosis (AK) has historically been evaluated in relation to the number of lesions requiring treatment or simply by the price of a single tube/sachet of the drug used. Objective: To demonstrate a new method of costing topical treatments in AK, which takes into account the actual cancerization area treated. Methods: In order to evaluate the actual cost of each treatment, the official approval status of the drug was used to estimate the amount of cream needed per one cm 2 . This value was then applied to the hypothetical cancerization area sizes to demonstrate the impact of the size treated on the actual cost of treatment. The price considered was the ex-factory price in Italy. Results: Areas which could be treated with a single tube/sachet of Metvix ® , Picato ® , Aldara ® , Solaraze ® and Zyclara ® were 200, 25, 25, 33.3 and 200 cm 2 , respectively. For the treatment of smaller areas (