Combined Photodynamic Therapy and Chemotherapy Using Local Intra-Arterial Intratumoral Administration of Chlorin e6 and Cisplatin: First Clinical Observations.

Despite advances in cancer treatment, head and neck squamous cell carcinoma (HNSCC) remains a serious clinical problem due to tumor aggressiveness, tumor resistance to therapy, and treatment toxicity. The combination of photodynamic therapy (PDT) with chemotherapy is a promising approach to improve efficacy while reducing side effects. For the first time, the possibility and antitumor effect of the combined use of PDT and chemotherapy with intra-arterial administration of chlorin e6 (Ce6) and cisplatin in patients with HNSCC were assessed. Two patients with locally advanced HNSCC received intra-arterial administration of Ce6 (at a dose of 0.5 mg/kg) and cisplatin (at a dose of 50 mg/m2) via a catheter into the tumor-feeding artery followed by laser irradiation. Ce6 distribution, tumor response, and treatment efficacy were assessed by fluorescence diagnostics, confocal microscopy, and histopathological analysis. Intra-arterial administration of the photosensitizer (PS) and chemotherapeutic agent ensured high selectivity of their tumor accumulation. Fluorescence diagnostics showed rapid and selective Ce6 accumulation in the tumor and PS photobleaching after PDT. For a patient with three PDT sessions, there is a significant acceleration of the Ce6 spread from the tumor-feeding artery throughout the tumor bed with each therapy session. This is a good sign of a tumor stroma density decrease. The combined use of PDT and chemotherapy with intra-arterial administration of Ce6 and cisplatin is safe and feasible, with preliminary evidence of local cytotoxicity treatment for HNSCC, allowing targeted drug delivery to the tumor. This is the first report of the combined use of PDT and chemotherapy with selective intra-arterial administration of a PS and a chemotherapeutic drug for the treatment of cancer.