2346 - Toxicities of Brain and Spinal Cord Photon and Proton Radiation in Pediatric Brain Tumors Assessed by Real-World Data (RWD)

Purpose/Objective(s): Proton therapy (PRT) may limit late radiation toxicities by minimizing exposure to nearby healthy tissues. Real-world data (RWD) can provide valuable information on such benefits revealing toxicities following radiation. Here, we assess the use of RWD to evaluate toxicities in children with brain tumors who were treated with either local or craniospinal (CSI) photon (PHT) or PRT.

Materials/Methods: A retrospective, cross-sectional analysis. Ninety-five pediatric patients with a brain tumor treated with local or CSI radiation between 2009-2019 from two university hospitals were identified, including ependymoma (23), medulloblastoma (22), gliomas (17), craniopharyngioma (11), embryonal tumors (9), germinomas (9), sarcoma of the brain (2), atypical choroid plexus papilloma (1), and ganglioneuroma (1). RWD from diagnostic claims billed in clinical encounters were collected to indicate various toxicities aligned with known toxicities for brain and spine radiation.

Results: Sixty-nine patients were treated with PHT and 26 with PRT. Thirty-one patients were treated with CSI (71% PHT). For all patients, there was no difference in gender (PHT=61% male; PRT=50% male), age at treatment (PHT=8.64±5.34yr; PRT=9.08±4.77yr), or length of follow-up (PHT=7.34±4.19yr; PRT=6.83±3.15yr). For all patients, there were no second tumors, chronic sinusitis, xerostomia, or osteoradionecrosis. Toxicities are portrayed in Table 1.

Conclusion: RWD is an additional way to screen for toxicities after PRT, offering additional information when combined with dosimetry data. A forthcoming chart review will assess the accuracy of RWD and assess potential confounds (i.e., other treatments, treatment intent, dosimetry, era of treatment, etc.).

^{Format: % of patients (range of onset in years)}