Positron Spectroscopy Investigation of Normal Brain Section and Brain Section with Glioma Derived from a Rat Glioma Model

The application of positron annihilation lifetime spectroscopy (PALS) and Doppler broadening spectroscopy (DBS) to the study of animal or human tissue has only recently been reported. We have initiated a study of normal brain section and brain section with glioma derived from a rat glioma model. PALS lifetime runs were made with the samples soaked in formalin, and there was not significant evaporation of formalin during the runs. While early results suggested a small decrease in o-Ps pickoff lifetime between the normal brain section and brain section with glioma, further runs with additional samples have showed no statistically significant difference between the normal and tumor tissue for this type of tumor. DBS was also used to investigate the difference in positronium formation between tumor and normal tissue. Tissue samples are heterogeneous and this needs to be carefully considered if PALS and DBS are to become useful tools in distinguishing tissue samples.