Investigation of the Mechanisms of Radio-Dynamic Therapy

Chang-Ming Charlie Ma,Guiping Xiao,Jun Zeng,Liang Wang,Lili Chen,Qiyin Sun,Quanshi Zhang

doi:10.30654/mjcs.10024

Abstract

Investigation of the Mechanisms of Radio-Dynamic Therapy

Highlights

Photodynamic therapy (PDT) uses light-activated drugs to treat diseases ranging from cancer to age- related macular degeneration and antibiotic-resistant infections
Our Monte Carlo results showed that the intensity of Cerenkov light induced by 45MV photons from a LA45 accelerator was 5-8 times of that induced by 6MV photons from conventional radiotherapy accelerators
The excitation effect for the homogeneous internal Cerenkov light distribution induced by 3D conformal radiation therapy (3DCRT) was over 10 times of that by external laser light that is nearly exponentially attenuated in conventional PDT

Summary

Introduction

Photodynamic therapy (PDT) uses light-activated drugs to treat diseases ranging from cancer to age- related macular degeneration and antibiotic-resistant infections. PDT involves the administration of a tumor-targeting photosensitizer or photosensitizer prodrug (e.g. 5-aminolevulinic acid [5-ALA], a precursor in the heme biosynthetic pathway) and the subsequent activation of the photosensitizer by light. The photosensitizer can accumulate selectively within tumor tissues and absorb visible light and subsequently transfer most of the absorbed energy to oxygen molecules. This process converts the oxygen into some relatively strong active oxidizing agents; such as singlet oxygen. Due to limited visible light depth penetration (usually, the effici t treatment depth is less than 7mm), PDT has not been extensively utilized clinically

Methods

Results

Conclusion