INNV-48. Capturing Off-Trial Supplement Use and Symptom Evolution in Pediatric Neuro-Oncology Clinical Trials: A Mixed Methods Study

Abstract n pediatric neuro-oncology, clinical trials often represent the frontline of care for high-risk brain tumors. However, families navigating these trials frequently pursue additional treatments—such as over-the-counter supplements, special diets, or therapies found online or through peer networks—that are not routinely disclosed to clinicians. These off-trial interventions pose potential risks of pharmacological interaction, yet remain poorly documented—particularly in diseases like diffuse midline glioma (DMG), where families are highly engaged in sharing treatment experiences. At the same time, families may underrecognize or underreport neurological or behavioral symptoms that could serve as early indicators of treatment response, disease progression, or toxicity. This mixed-methods study aims to gather foundational data to better understand and categorize the non-traditional treatments families explore alongside clinical trials. We will begin with qualitative interviews (~15 families) to examine which off-trial interventions are being used, the motivations behind them (e.g., managing side effects vs. treating the tumor), and barriers to disclosure. Interviews will also explore how families interpret changes in their child’s functioning—such as shifts in emotional regulation, thermoregulation, attention, or behavior—which may begin before treatment and evolve throughout care. These changes often go unreported due to uncertainty about their clinical relevance or whether they reflect normal developmental variation. Building on these findings, we will conduct a retrospective survey (~120 families) and a prospective journaling cohort (30 patients) to track symptom evolution and supplement use in real time. Data will inform development of a prototype tool prompting structured, age-stratified tracking across treatment stages. This work is especially relevant for the DMG community, where peer-to-peer information sharing is common. Developing a reliable, evidence-informed structure to support that exchange is critical to empowering families while minimizing unintended harm.