Pathologic Changes After Photodynamic Therapy for Basal Cell Carcinoma and Bowen Disease

Abstract

This study defines the time course and characteristics of the skin tumor response to PDT. Taken together, our observations suggest that direct damage to cancer cells is the main effector mechanism leading to PDT response. The involvement of apoptosis is demonstrated by the simultaneous appearance of histologic, immunohistochemical, and ultrastructural markers that occur in the early phases of the cutaneous reaction to PDT. These observations could help to develop future refinements of the PDT technique.