Photodynamic therapy for recurrent and residual malignant tumors of the oropharyngeal area

Abstract

The frequency of tumor recurrences, according to the modern literature, remains high even in early stages of cancer (15% to 35%), the efficacy of conventional therapy for recurrent tumors is insufficient. In the State Research Center for Laser Medicine in 1992-97 photodynamic therapy with russian photosensitizers Photoheme ((lambda) equals 630 nm) and Photosense ((lambda) equals 670 nm) has been applied to 42 patients with recurrent and/or residual tumors (size corresponding to T1 - T4 symbols) of oropharyngeal area. We used laser irradiation for 3 - 30 minutes, power density used was from 0.05 to 1.0 W/cm2, energy density - 300 J/cm2. Therapeutic effect in term from 3 to 45 months was achieved in 39 (92.9%) patients. Complete resorption of tumors took place in 23 (54.8%) cases, partial resorption - in 16 (38.1%); in 3 cases (7.1%) the results of PDT were assessed as no response (tumor size decrease by less than 50%). Absolute resistance to PDT has not been noticed. The data obtained shows that PDT is a promising treatment modality for managing recurrent and residual tumors of oropharyngeal area.