Brain tumor uptake of thallium‐201 from the cerebrospinal fluid compartment: A preliminary study of uptake and diffusion dynamics

Abstract

AbstractThallium‐201 (201Tl) has become a potent diagnostic tool for imaging brain tumors. Since intrathecal injections of 201T1 result in high resolution images of normal brain, experiments were designed to study tumor uptake and diffusion of 201T1 subsequent to cerebrospinal fluid (CSF) injection. A1SA5 astrocytoma cells were injected into the rat caudoputamen. Two weeks post‐implantation, rats received lateral ventricle injections of 201T1. Deeply anesthetized rats were perfused with 4.0% buffered formalin. Brains were removed, sectioned, and processed for autoradiography. Autoradiographs (ARGs) were developed and mounted sections were stained with hematoxylin and eosin. ARGs reveal a high degree of tumor to background resolution. Small tumor processes and cellular metastasis parallel to fiber tracts are readily visualized. 201TI labeling in areas of no apparent histologic disease, immediately surrounding and caudal to tumors, is suggestive of uptake by cells undergoing transformation. These studies are the first to demonstrate tumor uptake subsequent to 201T1 CSF injection and provide insights into the movement of 201T1 through tumor and adjacent neuropil. © Wiley‐Liss, Inc.