The main advantage of PDT treatment it is their non-invasive protocol that causes minimal damage to healthy tissue with lower level of side effect.  However, considering the lower penetration level of the laser light currently in use, and some limitation related the drug biodistributions, this therapy cannot pass through more than about 3 centimeters of tissue, restricting its application for the treatment of specific kind of neoplastic tissue.

Recently, some attempts have been described for developing PDT modalities involving the topical applications of the photosensitizing agents.  In this aspect, promising results were obtained by using phthalocyanines as a photosensitizer.  These second generation of photosensitizer compounds, which are highly colored, generally lipophilic, with excellent photophysical e photobiological properties, with lower or completely absence of side effect, has received the most attention regarding to photodynamic efficacy.

In this review, basic aspects of PDT were discussed, evaluating more specifically the phthalocyanines dyes as a promising second generation of photosensitizers, useful for topical and systemic application in neoplasic diseases.