INTRAOPERATIVE PHOTODYNAMIC THERAPY WITH M-TETRAHYDROXYPHENYLCHLORIN FOR CHEST MALIGNANCIES

Background and Objective: Since there is no satisfactory treatment mod ality for diffuse malignant mesothelioma of the chest, we assessed sur gical tumor resection followed by intraoperative photodynamic therapy with mTHPC in a phase I study. Study Design/Materials and Methods: Sin ce 1990, eight patients have undergone intraoperative photodynamic the rapy with m-tetrahydroxyphenylchlorin (mTHPC-PDT) following thoracotom y and surgical tumor resection. Results: mTHPC-PDT-mediated tumor necr osis was characterized by tumor infarction due to tumor vessel necrosi s and thrombosis, and its extent depended on drug-light conditions; 65 0 nm light delivered at 0.1 W/cm(2) for 10 J/cm(2) 48 h after iv admin istration of 0.3 mg mTHPC/kg resulted in a 10-mm-deep complete tumor n ecrosis. Skin photosensitivity was related to the drug dose applied an d occurred up to 17 days after iv administration of 0.3 mg mTHPC/kg, m THPC-PDT of brachial plexus infiltrated by mesothelioma resulted in pa in relief without deterioration of nerve function. Conclusion: Tumor r esection and intraoperative mTHPC-PDT of the chest cavity is feasible under clinical conditions and offers local tumor control of sites invo lved. However, distant tumor spread was not prevented by this combined treatment modality and optimization of mTHPC-PDT is warranted for fur ther intraoperative application. (C) 1996 Wiley-Liss, Inc.