Treatment for Central Nervous System Tumor

Recent advances in technology have allowed for the detection of cell-free DNA (cfDNA). cfDNA is tumor DNA that can be found in the fluid that surrounds the brain and spinal cord (called cerebrospinal fluid or CSF) and in the blood of patients with brain tumors. The detection of cfDNA in blood and CSF is known as a "liquid biopsy" and is non-invasive, meaning it does not require a surgery or biopsy of tumor tissue. Multiple studies in other cancer types have shown that cfDNA can be used for diagnosis, to monitor disease response to treatment, and to understand the genetic changes that occur in brain tumors over time. Study doctors hope that by studying these tests in pediatric brain tumor patients, they will be able to use liquid biopsy in place of tests that have more risks for patients, like surgery. There is no treatment provided on this study. Patients who have CSF samples taken as part of regular care will be asked to provide extra samples for this study. The study doctor will collect a minimum of one extra tube of CSF (about 1 teaspoon or 5 mL) for this study. If the patients doctor thinks it is safe, up to 2 tubes of CSF (about 4 teaspoons or up to 20 mL) may be collected. CSF will be collected through the indwelling catheter device or through a needle inserted into the lower part of the patient's spine (known as a spinal tap or lumbar puncture). A required blood sample (about ½ a teaspoon or 2 3 mL) will be collected once at the start of the study. This sample will be used to help determine changes found in the CSF. Blood will be collected from the patient's central line or arm as a part of regular care. An optional tumor tissue if obtained within 8 weeks of CSF collection will be collected if available. Similarities between changes in the DNA of the tissue that has caused the tumor to form and grow with the cfDNA from CSF will be compared. This will help understand if CSF can be used instead of tumor tissue for diagnosis. Up to 300 people will take part in this study. This study will use genetic tests that may identify changes in the genes in the CSF. The report of the somatic mutations (the mutations that are found in the tumor only) will become part of the medical record. The results of the cfDNA sequencing will be shared with the patient. The study doctor will discuss what the results mean for the patient and patient's diagnosis and treatment. There will not be any germline sequencing results reported and these will not be disclosed to the patient, patient's clinician or be recorded in patient medical record. Patient may be monitored on this study for up to 5 years.