Systematic Review of Photodynamic Therapy in Gliomas

Abstract

Over the last 20 years, gliomas have made up over 89% of malignant CNS tumor cases in the American population (NIH SEER). Within this, glioblastoma is the most common subtype, comprising 57% of all glioma cases. Being highly aggressive, this deadly disease is known for its high genetic and phenotypic heterogeneity, rendering a complicated disease course. The current standard of care consists of maximally safe tumor resection concurrent with chemoradiotherapy. However, despite advances in technology and therapeutic modalities, rates of disease recurrence are still high and survivability remains low. Given the delicate nature of the tumor location, remaining margins following resection often initiate disease recurrence. Photodynamic therapy (PDT) is a therapeutic modality that, following the administration of a non-toxic photosensitizer, induces tumor-specific anti-cancer effects after localized, wavelength-specific illumination. Its effect against malignant glioma has been studied extensively over the last 30 years, in pre-clinical and clinical trials. Here, we provide a comprehensive review of the three generations of photosensitizers alongside their mechanisms of action, limitations, and future directions.

The use of photodynamic therapy in medical practice

“…The influence of both first and second generation photosensitizers was tested. Most studies have confirmed the significant effectiveness of the therapy, but further studies are necessary to better define the effectiveness of PDT ( 116 , 236 , 237 ). In Germany, in 2007, Stepp et al.…”

Glioblastoma Therapy: Past, Present and Future

“…Protoporphyrin IX (PpIX) and fluorescein are most widely used as PS and as SS due to their safety profile and selective accumulation in tumor cells, and most studies in glioma use 5-aminolevulinic acid (5-ALA) as a precursor of PpIX [ 1031 , 1032 , 1033 ]. After surgery and adjuvant treatment, the residual tumor is predominantly comprised of resistant GSC clones; thus, several strategies have attempted to enhance 5-ALA uptake by this type of cells in order to increase the efficacy of PDT and SDT [ 1032 , 1033 ]. Moreover, iron chelators, such as deferoxamine and CP94, and ABC transporter inhibitors have been shown to increase PpIX levels in GB cells when utilized as adjuvants [ 1034 , 1035 ].…”

Carbomer Hydrogel Composed of Cu2O and Hematoporphyrin Monomethyl Ether Promotes the Healing of Infected Wounds

“…Photodynamic therapy (PDT) is a newly developed strategy for disease diagnosis and treatment using photodynamic effects . When photosensitizers were triggered and activated by laser in a given wavelength, the local reactive oxygen species (ROS) would increase and destroy the cell structure such as cell membrane, protein and even nucleic acids . This method has a different mechanism than traditional antibiotics, which enables antibiotic resistance could be controlled in a new way .…”

“… 2 When photosensitizers were triggered and activated by laser in a given wavelength, the local reactive oxygen species (ROS) would increase and destroy the cell structure such as cell membrane, protein and even nucleic acids. 3 This method has a different mechanism than traditional antibiotics, which enables antibiotic resistance could be controlled in a new way. 4 It is well-known that PDT processes advantages such as fewer side effects and localized treatment.…”