Laser induced thermotherapy of multiple actinic keratosis

Abstract

Actinic keratosis (AK) is one of the most common precancerous diseases of the skin, which is characterized by local intraepidermal atypia of keratinocytes that occurs under the influence of ultraviolet radiation, clinically manifested by typical foci of hyperkeratosis in exposed areas of the skin. This is an urgent medical and social problem due to the potential tendency of atypical keratinocytes to malignant transformation, proliferation of keratinocytes and their spread beyond the epidermis with the development of tumor progression [1]. Recently, a number of authors have established important features of the course of this precancerous tumor. First of all, we are talking about an increased risk of malignant transformation of AK into squamous cell carcinoma in the presence of a history of visceral malignancy, as well as the same changes in the lesion and the adjacent clinically unaffected skin in the form of accumulation of genetic and epigenetic mutations that form "cancerization fields" [ 33,34], indicating the need to treat AK, especially multiple foci, using the ablastic rule with the capture of 1-1.5 cm of apparently healthy skin [35,36]. For the treatment of multiple AK foci in a patient with an aggravated oncological history, for the first time, we used, in an independent version, a modern method of treatment - laser-induced thermotherapy (LITT). LITT is a non-invasive, antitumor, immunomodulatory method based on the selective death of atypical keratinocytes in the epidermis by local tissue heating to a temperature of 42.5-44℃ (hyperthermia) caused by infrared laser radiation with a wavelength of 800-1300 nm. The presented case of AK in a patient with breast cancer in history was characterized by a combination of keratotic and erythematous forms of the tumor. At the same time, LITT with an extended exposure zone by 1 cm from the visible boundaries of the lesions was not only clinically effective in terms of immediate and long-term results, but also gave an excellent cosmetic result with a completely satisfactory tolerability of the treatment procedure.