Photodynamic therapy for the treatment of squamous cell carcinoma using benzoporphyrin derivative.

BACKGROUND

Photodynamic therapy (PDT) involves laser light excitation of a tumor-localizing photosensitizer to destroy neoplasms. Benzoporphyrin derivative (BPD) is a new photosensitizer with several favorable characteristics.

OBJECTIVE

Studies were designed to: 1) assess the efficacy of BPD-mediated PDT in treating in vivo squamous cell carcinomas (SCC); 2) obtain dosimetry data for BPD and laser parameters; and 3) establish clinical and histologic correlates of BPD-induced tumor regression.

METHODS

Human SCC was implanted into nude mice. One group received BPD followed by laser light of 150 J/cm2 from an argon-pumped dye laser at 690 nm. Three control groups included laser energy alone, BPD alone, and no treatment.

RESULTS

At day 21 posttreatment only PDT-treated tumors showed a statistically significant decrease in tumor volume and complete cure rate. Clinical resolution (scar) correlated perfectly with histologic resolution (scar).

CONCLUSION

Human SCC in a nude mouse model responds to BPD-mediated PDT.