The role of screening spinal MRI in children with solitary posterior fossa low-grade glial tumors

OBJECTIVE Solitary posterior fossa low-grade glial tumors (SPFLGT) in children are rarely associated with leptomeningeal dissemination (LMD). To date, there are no clear guidelines regarding the role of screening and surveillance spinal MRI (sMRI) in children with SPFLGT, at diagnosis or during follow-up periods. The current study reviews a cohort of children with SPFLGT, focusing on sMRI findings. METHODS In this binational retrospective study, the authors analyzed 229 patients with SPFLGT treated and followed over 13 years. One hundred twelve children had at least 1 total sMRI screening or surveillance examination. One hundred seventeen had no sMRI, but did not present with clinical spinal signs or symptoms. Collected data included demographics, disease characteristics, radiology, pathology, and clinical follow-up data. RESULTS For the 112 children with at least 1 sMRI, the mean duration from diagnosis to first sMRI was 11.73 ± 28.66 months (range 0–165 months). All sMRI scans were conducted as screening examinations, with no spinal-related symptoms. One patient was found to have a sacral intradural lesion concurrent to the brain tumor diagnosis. Over the course of 180 radiological and 533 clinical follow-up years for the 112 patients with sMRI, and 582 clinical follow-up years for the 117 patients with no sMRI, there were no additional cases with spinal tumor spread. CONCLUSIONS The yield of screening sMRI in the absence of cranial metastasis, or spinal symptoms, is extremely low. Because preoperative sMRI is recommended for medulloblastomas and ependymomas, it may be logical to acquire. During the follow-up period the authors recommend limiting sMRI in patients without symptoms suggesting a spinal lesion, in patients without known cranial metastases, or recurrence or residual SPFLGT.