The concerns that Dilkes and McGilligan have raised are certainly real and are the same concerns that I had before treating patients with intraoperative adjuvant PDT using porfimer sodium.
It is critical that proper preclinical animal studies be performed before PDT is used in humans to determine the appropriate light and drug doses that cause minimal or no damage to normal tissue. In most cases, the results found in small rodent models do not approximate the results found in humans. Likewise, each photosensitizer behaves differently and must be evaluated separately. In experiments in my laboratory using the dog as a model, in which the response is closely approximated with that seen in humans,1 PDT using porfimer sodium, 2 mg/kg intravenously, followed by 50J/cm2 at 150 mW/cm2 of 630-nm light 48 hours later, caused no intrinsic damage to large arteries in the neck, including the carotid
Biel MA. Adjunctive Intraoperative Photodynamic Therapy and Microvascular Anastomoses-Reply. Arch Otolaryngol Head Neck Surg. 1997;123(8):888. doi:10.1001/archotol.1997.01900080122018