Drug and light dose dependence of PDT on pancreatic cancer cells in vitro

Photodynamic therapy (PDT) is a promising new treatment for a variety of malignant tumors. Recently, PDT has been investigated as an alternative treatment for pancreatic carcinoma. The selection of photosensitizer and laser light are equally important for the treatment efficacy. The purpose of this study is to evaluate drug and light dose dependence of photodynamic effect in pancreatic cancer cells. Zinc tetrasulfonated phthalocyanines used as photosensitizer and a novel diode laser system terminated at alight shaping diffuser was used as light source. Viability was measured 24 and 72 hours after treatment and almost 100 percent lethality levels were achieved, by using low light doses independently of drug concentration. The results are discussed in correlation with light and drug doses.