The objective of the present study was to investigate the treatment of 9L
gliosarcoma brain tumor in the rat with the combination of surgical resection and
photodynamic therapy (
PDT). Nude rats with intracranial 7-day-old 9L
gliomas were randomly subjected to no treatment,
PDT alone (
Photofrin: 2 mg kg(-1), optical: 80 J cm(-2)), surgical resection alone or resection combined with 2 mg kg(-1)
Photofrin-mediated
PDT at an optical dose of 80 J cm(-2). All animals were sacrificed 14 days after
tumor implantation.
Hematoxylin-and-
eosin and immunohistochemical stainings were performed to assess the
tumor volume and the expression of
vascular endothelial growth factor (
VEGF) in the brain adjacent to the
tumor (BAT) as well as the
tumor cell apoptosis and proliferation. Our data show that both surgical resection alone and
PDT alone significantly decreased
tumor volume, but furthermore, surgical resection combined with
PDT significantly reduced the
tumor volume and reduced local
tumor infiltration compared to either surgical resection or
PDT treatment alone.
PDT treatment with or without resection increased
tumor apoptosis, but resection alone did not alter the
tumor cell apoptosis compared with a nontreatment control group. Both surgical resection alone and
PDT alone induced a significant increase in
VEGF expression in the BAT; however intraoperative
PDT did not further increase
VEGF expression, compared with surgery alone or
PDT alone. No significant differences were found in
tumor cell proliferation as indicated by Ki67 immunoreactivity among the four groups. Our results suggest that
PDT enhances the efficacy of surgical resection in the management of
malignant gliomas without increasing
VEGF expression in the BAT.