Value of postoperative surveillance imaging in the management of children with some common brain tumors

The rationale for obtaining surveillance computerized tomography (CT) scans or magnetic resonance (MR) images in pediatric patients with brain tumors is that early detection of recurrence may result in timely treatment and better outcome. The purpose of this study was to investigate the value of surveillance cranial images in a variety of common pediatric brain tumors managed at a tertiary care pediatric hospital. A retrospective chart review was performed of children with astrocytoma of the cerebral hemisphere, cerebellum, optic chiasm/hypothalamus, or thalamus; cerebellar or supratentorial high-grade glioma; supratentorial ganglioglioma; posterior fossa or supratentorial primitive neuroectodermal tumor (PNET); and posterior fossa ependymoma. Data were analyzed to determine the frequency with which recurrences were identified on a surveillance image and how the type of image at which recurrence was identified related to outcome. In 159 children, 17 of 44 recurrences were diagnosed by surveillance imaging. The percentage of recurrences identified by surveillance imaging was 64% for ependymoma, 50% for supratentorial PNET, 43% for optic/hypothalamic astrocytoma, and less than 30% for other tumors. The rate of diagnosis of recurrence per surveillance image varied from 0% to 11.8% for different tumor types. Only for ependymomas did there appear to be an improved outcome when recurrence was identified prior to symptoms. Our results indicate that, using the protocols outlined in this study, surveillance imaging was not valuable in identifying recurrence of cerebellar astrocytoma or supratentorial ganglioglioma during the study period, but was probably worthwhile in identifying recurrence of posterior fossa ependymoma and optic/hypothalamic astrocytoma and, possibly, medulloblastoma. Surveillance protocols could be made more effective by individualizing them for each type of tumor, based on current data on the patterns of recurrence.