Photodynamic therapy and photothermal therapy for the treatment of peritoneal metastasis: a systematic review

BACKGROUND: The aim of this review was to analyze preclinical studies and clinical trials evaluating photodynamic therapy (PDT), and photothermal therapy (PTT) in peritoneal metastasis (PM) treatment. CONTENT: Systematic review according PRISMA guidelines. Electronic searches using PubMed and Clinical Trials. SUMMARY: A total of 19 preclinical studies analyzing PDT in PM treatment were included. Each new generations of photosensitizers (PS) permitted to improve tumoral targeting. Phase III preclinical studies showed an important tumoral biodistribution (ratio 9.6 vs normal tissue) and significant survival advantage (35.5 vs 52.5 days for cytoreductive surgery vs cytoreductive surgery+PDT, p<0.005). Height clinical trials showed important side effects (capillary leak syndrome and bowel perforation), mainly explained by low tumor-selectivity of the PS used (first generation mainly). Peritoneal mesothelioma apparition with carbon nanotubes first limited the development of PTT. But gold nanoparticles, with a good tolerance, permitted a limitation of tumoral growth (reduction of bioluminescence to 37 % 20 days after PTT), and survival benefit (35, 32, and 26 days for PTT with cisplatine, PTT alone and laser alone, respectively). OUTLOOK: Recent improvement in tumor-selectivity and light delivery systems is promising but further development would be necessary before PDT and PTT routinely applied for peritoneal carcinomatosis.