Evolution of Technology

Photodynamic Therapy

Photodynamic therapy is a type of treatment that uses a light sensitizing medication put on the skin or into the bloodstream, which is then activated by light from a laser or other light sources, to kill the desired cell type, most often cancer and precancer cells.

Evolution of Procedure


Cryotherapy (use of liquid nitrogen) is probably the most familiar treatment. However, only lesions that are felt or seen are treated. There are many topical medications that can be used for treatment. This is typically done when there are numerous lesions or recurrence is frequent. Some disadvantages of topical medication are the duration of treatment and the side effects (redness, swelling, crusting of the skin), both of which can lead to noncompliance.

Evolution of Diagnosis

Actinic Keratoses

Actinic Keratoses (AKs) are precancerous lesions that can develop into squamous cell carcinoma. AKs are one of the most common skin conditions that dermatologists treat. They develop because of an abundance of UV exposure on unprotected skin. The scalp, face, neck, forearms, and hands are most affected. AKs present as red, scaly, non-healing lesions that are often better felt than seen. Because AKs can be a manifestation of sun exposure from the past and present, patients often come to the office regularly to treat lesions.