CT-guided laser therapy in resistant human tumors: phase I clinical trials

Photodynamic therapy was performed on ten tumors in patients who did not respond to initial therapy and for whom no additional conventional therapy was available. A sensitizing agent (hematoporphyrin derivative [HpD]) was injected directly into each tumor under computed tomographic (CT) guidance to deliver high concentrations to the tumor and to minimize systemic toxicity. Three to 6 days after the injection, a clear Teflon sheath catheter was placed into the tumor under CT guidance. The tumor was exposed to red light (630-nm wavelength) through laser fiberoptics inserted in the sheath. The initial investigation confirmed the technical feasibility of CT-guided photodynamic therapy by means of intratumoral HpD injections and laser exposure through fiberoptics inserted in sheath catheters. The toxicity from a single treatment was minor, and the tumor response was encouraging.