Applied Photosensitizers Classification for Clinical Photodynamic Therapy

Abstract

Evidently there is no one ideal photosensitizer for all malignancies, but there are many photosensitizers, each with a specific affmity for various types of tumours. In this study photosensitizers are classified according to their activity times in tumours into three categories; short-acting, intermediate-acting and long-acting photosensitiz-ers. Short-acting photosensitizers, show their maximum concentration and retention period between 2h-24h post injection as pheophorbide and chlorine. Intermediate-acting photosensitizers as the aluminium and silicon phthalocyanine, show their maximum concentrations between 24h-72h. Long-acting photosensitizers with a retention periods from 72h-288h post injection as hematoporphyrin derivatives, tetraphenyl porphyrin sulphate, zinc phthalocyanine and Evan blue. Short-acting photosensitizers will be suitable for surface lesions when light irradiation applied at short time. While both the intermediate-and long-acting photosensitizers will be suitable for internaliesions. This classification will be more relevant when selecting the appropriate photosensitizer.