<title>Imaging of folate receptors with I-125 labeled folate using small animal imaging system built with plastic scintillating optical fibers</title>

Abstract

A small animal whole body imaging device was built with plastic scintillating fibers and application of this system to image folate receptors in mice is described. The prototype imaging device consisted of two layers of 1 mm BCF-10 fibers laid on 6.98 cm acrylic core, one layer with a right handed pitch and the other with a left handed pitch. The fiber readout was performed with a position sensitive photomultiplier and a specialized flash ADC. A coaxial brass mesh collimator (1 mm thick) was used to increase spatial resolution. Histamine- folate conjugate was labeled with I-125 and was found to have receptor binding properties similar to 3H labeled compound. Imaging studies were performed in mice bearing folate receptor +ve (IGROV) tumor and receptor -ve (Meth-A) tumor. In situ imaging of animals sacrificed at 30 min post injection of the tracer showed the localization of the tumor in animals with the folate receptor +ve tumors and the results were negative in animals with receptor -ve tumor. The biodistribution studies confirmed these observations. Our initial studies demonstrate the prospects for development of agents for imaging folate receptors that may have application in drug development and the application of the small animal imaging device built with plastic scintillating detectors in imaging with low energy photons (25 - 35 keV).© (1994) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.