Hematoporphyrin derivative and laser photodynamical reaction in the diagnosis and treatment of malignant tumors

This paper reports the use of hematoporphyrin derivative (HpD) with laser activation in China for the diagnosis and treatment of various kinds of malignant neoplasms. Fluorescence observation for diagnosis was performed for 170 tumors. One hundred and fifty-one (88.8%) fluoresced visably upon excitation with either argon or He-Cd laser light. One hundred and thirty-nine malignant tumors in 136 patients were treated by this method. The percentage of all tumors responding to treatment was 80.6%. Partial to complete response were obtained in 51.1% of the tumors treated. The advantages and disadvantages of this method are discussed. It was found effective in treating various kinds of neoplasms located at different anatomical sites. The penetrating depth of the laser is shallow. This limits its effect and application. A search for new photosensitizing drugs and an increase in the penetrating depth of laser irradiation are urgent goals for further development of this technique.