Hematoporphyrin derivative photoradiation therapy in murine solid tumors

The cytocidal activity of light-activated hematoporphyrin derivative (Hpd) in experimental and human tumors is under investigation in many laboratories. This activity is based upon preferential incorporation of Hpd in malignant tissues and its photosensibilization by red light. Treatment of mice bearing MS-2 fibrosarcoma and B 16 melanoma, a metastatic tumor, with Hpd and laser light, externally or delivered through a quartz fiber optic imbedded directly into the tumor, significantly prolonged the median survival time. This therapy was compared with surgical excision of primary tumors, and preliminary results on metastatic neoplasm suggest that the photoradiation therapy is more effective than surgery.