Photodynamic Therapy: A Brief History.

David Kessel

doi:10.3390/jcm8101581

Abstract

Photodynamic therapy (PDT) involves the selective sensitization of tissues to light. A major advance in the field occurred when Thomas Dougherty at the Roswell Park Cancer Institute initiated a series of clinical studies that eventually led to FDA approval of the procedure. This report contains a summary of Dougherty’s contributions and an assessment of where this has led, along with a summary of implications for future drug development.

Highlights

The first literature reports of a ‘photodynamic effect’ were provided by Raab and von Tappeiner [1,2]
In 1948, Figge summarized a series of studies showing that exogenously-provided porphyrins selectively accumulated in murine tumors [3]
This study was later extended to include cancer patients: injection of a crude preparation of hematoporphyrin led to selective tumor fluorescence [4]

Summary

Introduction

The first literature reports of a ‘photodynamic effect’ were provided by Raab and von Tappeiner [1,2]. In 1948, Figge summarized a series of studies showing that exogenously-provided porphyrins selectively accumulated in murine tumors [3]. This study was later extended to include cancer patients: injection of a crude preparation of hematoporphyrin led to selective tumor fluorescence [4]. The field of clinical PDT was further advanced when a group of physicians at the Mayo Clinic reported that tumor fluorescence in patients was enhanced when a ‘derivative’ of hematoporphyrin was employed [5,6]. The nature of this material was not revealed in the initial reports. Later studies revealed that it consisted of a mixture of porphyrin monomers, dimers, and higher oligomers

The First Photosensitizers

Mechanisms of Photokilling

New Photosensitizers and Combinations

Formulations and Optimization

Implications