Objectives: We studied photodynamic diagnosis (PDD) and therapy (PDT) applicability using NPe6 in with oropharyngeal cancer patients.
Methods: Of 11 subjects diagnosed with oropharyngeal cancer undergoing PDT and PDD using NPe6, 6 were stage T1 and 5 stage T2. None had nodal or distant metastases. Four hours before PDD, NPe6 (40 mg/mD) was injected intravenously. Under general anesthesia, tumor fluorescence observed by laser irradiation, and marked was followed by PDT and photobleaching was confirmed. Tissue collected from tumor centers confirming NPe6 was then compared to normal tissue specimens and the relationship between NPe6 concentration and treatment effectiveness studied.
Results: Tumor marking enabled us ensure a safety margin because the fluorescence scope exceeded tumor scope to the naked eye. Photobleaching was confirmed in all subjects. NPe6 tumor tissue concentration was 1.57-6.84 microg/g, with a ratio of 2.32-5.69 compared to normal tissue. Treatment achieved complete recovery (CR) in all subjects and shortened hospitalization over other treatment such as radiation.
Conclusion: PDD using NPe6 clearly benefited oropharyngeal cancer patients, and made PDT more accurate. NPe6 accumulated more than twice the level in tumor tissue than in normal tissue.