EXPERIMENTAL PANCREATIC-CANCER IN THE RAT TREATED BY PHOTODYNAMIC THERAPY

Selective histological necrosis of experimental pancreatic carcinoma by photodynamic therapy (PDT) has been successful with haematoporphyrin derivatives and phthalocyanine as photosensitizers. This report describes the feasibility of PDT with pheophorbide A as the photo-sensitizer to treat azaserine-induced pancreatic rat carcinoma and analyses survival of the animals. An organ distribution study 24 h after pheophorbide A administration (9 mg/kg intravenously) gave a selectivity ratio of 13.5:1 between tumour and surrounding tissue. Light of 660 mm and 100 J/cm(2) induced selective necrosis of the tumour. Six of nine rats Were cured in 120 days whereas all 36 control animals died within 35 days (P<0.01). The pancreas and hepatic pedicle were relatively unaffected by PDT, but the duodenum was injured.