Assessing Cerebrospinal Fluid Flow Dynamics in Pediatric Patients with Central Nervous System Tumors Treated with Intraventricular Radioimmunotherapy.

The incidence of abnormal cerebrospinal fluid (CSF) flow dynamics in children with central nervous system (CNS) tumors before intraventricular therapy has not been described. Methods: We performed a single-institution, retrospective review of patients with primary or metastatic CNS tumors treated between 2003 and 2018 (15 y). Patients underwent 111In-diethylenetriaminepentaacetic acid injection into the CSF intraventricular space followed by nuclear medicine imaging at 90 min, 4 h, 24 h, and 48 h (if required). CSF flow was classified as normal, delayed, asymmetric, or obstructed. Results: In total, 278 CSF flow studies were performed on 224 patients, 202 of whom (90%) were less than 18 y old. Of these, 116 patients (52%) had metastatic CNS neuroblastoma, 57 (25%) had medulloblastoma, and 51 (23%) had other histologic types of CNS tumors. Of the 278 studies, 237 (85%) were normal, 9 (3%) required neurosurgical intervention, 25 (9%) were delayed, and 7 (3%) were asymmetric. Conclusion: Abnormal CSF flow and the necessity for neurosurgical intervention must be considered when attempting to ensure appropriate intraventricular therapy in the pediatric population.