Fluorospectral study of the rat brain and glioma in vivo

Abstract

An animal model of cerebral glioma was utilized by implanting C6 glioma cells into the brains of adult Wistar rats. Once tumors developed to 7-12 mm in diameter, we conducted continuous fluorimetry monitoring of glioma up to 24 hours using a fibre-optic system connected to an intensified multichannel photodetector after an intravenous injection of hematoporphyrin derivative (HPD) into the rats. The intensity of the fluorescence in normal brain reached a plateau 6 hours after intravenous injection of HPD while that in glioma reached a plateau 80 minutes after injection. These fluorescence intensities of glioma, brain adjacent to tumor (BAT), and surrounding normal brain were measured in vivo 24 hours after intravenous administration of 5 mg/kg of HPD. The ratio of fluorescence intensities between glioma and brain was 6.1 while the ratio between BAT and brain was 3.9. There were no obvious differences in shapes between the spectra of the natural fluorescence (autofluorescence) of rat glioma and brain but the intensity of autofluorescence was much weaker in glioma. There are many problems in spectroscopic studies of biological tissues in vivo. It cannot be overemphasized that very strict criteria must be applied in order to get accurate data. Fluorescence from HPD administration may be used to discriminate tumor tissue from surrounding normal brain tissue during operation if the measuring conditions could be kept constant. It is important to understand the photospectral properties of glioma and brain tissue in order to get the most benefits in clinical application of light-induced fluorescence or photoradiation therapy.

Comparative study on the ALA photodynamic effects of human glioma and meningioma cells

“…Consequently, the current strategies are to resect the tumor as much as possible without inducing fur-ther neurological deficit of the patient, and then follow with adjuvant therapies such as radiation therapy, interstitial brachytherapy, and chemotherapy. In our previous study, we demonstrated that the ratio of the amount of HPD between glioma and brain was 6.1, whereas the ratio between brain adjacent to tumor and brain was 3.9 [13]. In this study, we showed that ALA-PDT could effectively kill glioma cells in vitro.…”

Physiological and Pathological Factors of Human Breast Disease That Can Influence Optical Diagnosisa

“…Exogenous fluorophores including 1) fluorescent photosensitizers, 59–67 2) fluorescent dyes, 69,70 3) fluorophortagged cancer‐specific antibodies 71 and 4) macromolecular carriers 65 are being investigated as agents to enhance fluorescence contrast of superficial and deeply seated cancers. Relative cancer selection for diagnosis and treatment is based on accumulation peaks appearing in the tumor at a different time than in the surrounding tissues.…”

Diagnostic Potential of Autofluorescence for an Assisted Intraoperative Delineation of Glioblastoma Resection Margins¶

“…Fluorescence spectroscopy has already been proposed as a diagnostic technique for the intraoperative delineation of tumor resection margins based on the emission properties of both exogenous (15–18) and endogenous (19–22) fluorophores.…”