What will happen during the study?
Eligible patients will be identified at weekly disease team meetings by a research team member, or by the inpatient oncology physician. Patients deemed eligible will be approached at diagnosis by a study team member to obtain consent (age ≥18-21) or assent (patients aged ≥10-17) from interested patients. Patient age was chosen due to established cuff-off values of Nfl, including a recent large cohort providing normative values, and to focus on high risk ALL patients (age ≥10 years). Patients must enroll within 5 days of receiving their first dose of VCR. Participants will be followed with NCS and Nfl from peripheral blood, and clinician grading at 3 timepoints. CEP72 will be obtained at baseline, following clearance of peripheral blasts. Time Point (TP) 1 will occur at baseline for all patients. TP 2 is dependent on patient protocol and will occur at 50% planned VCR exposure (for ALL interim maintenance 1, Lymphoma cycle 3, RMS week 22), TP 3 will correlate with maximum VCR exposure at end of therapy for lymphoma and RMS, and the start of maintenance for patients with leukemia correlating with maximum VCR exposure in all groups. Blood draws and CTCAE grading will occur during routine visits by the clinical research nurse (CRN) and timed with existing laboratory orders and port access. Participants have routine blood draws as part of standard clinical care at each chemotherapy visit by our CRN. CEP72 and Nfl via blood draw will be collected by existing central line or venipuncture while labs are otherwise obtained for clinical purposes.