Eligibility Screening for a NCI Pediatric Oncology Branch Research Study

Patients who are being considered for participation in a NCI Pediatric Oncology Branch research study will be screened for eligibility under this protocol. For every NCI research study, patients must meet defined medical criteria in order to ensure the integrity of the research study and to maximize patient safety. Tests and procedures required for determining eligibility depend on the specific study for which the patient is being considered. Some of the more common tests and procedures are: * History and physical examination * Blood and urine samples for routine laboratory tests and possibly research studies * Quality of life assessment questionnaire * Magnetic resonance imaging (MRI) scan uses a magnetic field and radio waves to produce pictures of body structures, including tumors * Computerized tomography (CT) scan uses radiation to produce multiple detailed pictures of body structures * X-rays uses radiation to provide a single picture of a body part * Nuclear medicine scans uses a chemical tagged with a radioactive substance to detect tumors, measure kidney or heart function, or monitor the flow of cerebrospinal fluid (fluid that bathes the brain and spinal cord) * Electrocardiogram (EKG) uses electrodes placed on the skin to evaluates heart rate and rhythm by measuring electrical impulses from the heart * Echocardiogram uses high-frequency sound waves to evaluate heart structure and function * Lumbar puncture tests for cancer cells and other substances in cerebrospinal fluid. Involves placing a needle into the lower back between the bones of the spine and withdrawing a fluid sample from the fluid-containing space below the spinal cord * Ommaya reservoir surgically implanted catheter inserted into the fluid-filled ventricles of the brain, used to withdraw spinal fluid samples and to give medication * Eye examination vision test and eye examination * Biopsies removal of a small piece of tissue, by needle or by surgery, for examination under the microscope. An