Photoradiation Therapy of Animal Tumors and Nasopharyngeal Carcinoma

Both animal tumors and human nasopharyngeal carcinoma were submitted to a photoradiation therapy (PRT) trial in order to determine the efficacy and side effects of PRT, as well as to elucidate its mechanism of cytotoxicity. In animal tumors, the inhibition rate was 70%, and of 20 patients, eight achieved complete remission, and ten, significant remission, with an overall response rate of 90%. The blood picture and the values of serum IgG, IgM, IgA, and C3 all remained stable post-PRT. Only three patients developed mild generalized skin photosensitive reactions, and these did not affect subsequent treatment. There was no immunosuppressive effect as evidenced by a tritium-labeled thymidine–incorporated lymphocytoblast transformation assay performed both before and after PRT. Ultrastructural studies at different time intervals after PRT highly suggested that the mitochondria and rough endoplasmic reticulum were among the first organelles to be damaged.