Premium
Photodynamic therapy of newly implanted glioma cells in the rat brain
Author(s) -
Madsen Steen J.,
AngellPetersen Even,
Spetalen Signe,
Carper Stephen W.,
Ziegler Sarah A.,
Hirschberg Henry
Publication year - 2006
Publication title -
lasers in surgery and medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.888
H-Index - 112
eISSN - 1096-9101
pISSN - 0196-8092
DOI - 10.1002/lsm.20274
Subject(s) - photodynamic therapy , photosensitizer , glioma , pathology , histopathology , brain tumor , medicine , in vivo , biodistribution , cancer research , biology , chemistry , microbiology and biotechnology , organic chemistry
Background and Objective A syngeneic rat brain tumor model is used to investigate the effects of aminolevulinic acid (ALA)‐mediated photodynamic therapy (PDT) on small clusters of tumor cells sequestered in normal brain. Study Design/Materials and Methods Biodistribution studies on tumor‐bearing animals were undertaken in order to determine the occurrence of photosensitizer in tumor cells invading normal brain. ALA–PDT toxicity in normal brain and gross tumor were evaluated from histopathology. Effects of PDT on isolated glioma cells in normal brain were investigated by treating animals 48 hours after tumor cell implantation. Results Fluorescence microscopy of frozen tissue sections showed that photosensitizer content was limited and variable in tumor tissue invading normal brain. ALA–PDT with high light doses resulted in significant damage to both gross tumor and normal brain, however, the treatment failed to prolong survival of animals with newly implanted glioma cells. In contrast, animals inoculated with tumor cells pre‐incubated in vitro with ALA showed a significant survival advantage in response to PDT. Conclusion The results show that ALA–PDT could not prevent tumors from forming if treatment was performed shortly after tumor initiation. This was likely due to inadequate levels of ALA/PpIX in the glioma cells. Lasers Surg. Med. © 2005 Wiley‐Liss, Inc.