Proceedings: Photochemotherapy. A study of its efficacy in fifty patients suffering from psoriasis and other dermatoses

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.

Photochemotherapy in the treatment of psoriasis

This article describes the satisfactory clinical improvement obtained in the majority of a group of 72 patients with psoriasis of various types as a result of the oral and/or topical administration of 8-methoxypsoralen followed by long wavelength ultraviolet irradiation. The irradiation source used was that of conventional longwave UV fluorescent tubes mounted in a specially constructed cubicle. Until such time as the long term effect of this form of photochemotherapy on the cell has been evaluated and the most appropriate regime worked out, it would seem to be important to restrict the amount of irradiation used to that required to produce acceptable maintained clinical improvement.