Baseline Anxiety Trajectories in Pediatric Radiation Therapy Observational Cohort

Inclusion Criteria: To be eligible to participate in this study, an individual must meet all of the following criteria: * Provision of signed and dated informed consent from a parent or legal guardian. * For children age 7 and older, provision of informed assent in addition to parental consent, consistent with institutional guidelines. * Stated willingness of parent/guardian and child (as appropriate) to comply with study procedures (i.e., observation during scheduled radiation therapy appointments). * Male or female, ages 2-12 years. * Scheduled to undergo radiation therapy at MD Anderson Cancer Center. Exclusion Criteria: An individual who meets any of the following criteria will be excluded from participation in this study: * Has already completed the simulation session for radiation therapy prior to enrollment. * Declines parental consent or, when applicable, child assent.