ABSTRACT
A clinical trial is “any form of planned experiment which involves patients and is designed to elucidate the most appropriate treatment of future patients with a given medical condition.”1 This definition describes concisely the structured clinical investigation necessary to acquire a clear understanding of the prognosis and treatment of pediatric central nervous system (CNS) tumors. The definition encompasses a spectrum of types of clinical trials, which differ in their objectives, complexity, target population, duration, and the numbers of patients involved.
