LOCATION OF BRAIN TUMORS WITH POLYVINYLPYRROLIDONE-I131.

Abstract

In recent years, improvements in instrumentation (collimators, mechanical scanning devices, and so forth) and the availability of a greater variety of radioactive isotopes and substances labelled with isotopes have led to renewed optimism regarding the use of scanning methods for locating intracranial tumors. To the clinician these methods represent a valuable adjunct to standard contrast studies, and to the patient, a more tolerable diagnostic procedure. Various agents, including arsenic, copper, potassium, phosphorus, iodoalbumin, and sodium iodide, have been used, paralleling progressive refinement of detection systems. 1-7 However, results have been of limited value, until the recent introduction of chlormerodrin, 8 with accuracy remaining considerably below that afforded by the classical contrast studies. Part of the reason for this failure is the accumulation of the tracer agents in muscle, thereby interfering with detection of lesions in the posterior fossa deep to the suboccipital musculature. Also there has been concern about irradiation