Optimizing Postoperative Surveillance of Pediatric Low-Grade Glioma Using Tumor Behavior Patterns

BACKGROUND Pediatric low-grade gliomas are among the most common childhood neoplasms, yet their post-treatment surveillance remains nonstandardized, relying on arbitrarily chosen imaging intervals. OBJECTIVE To optimize postoperative magnetic resonance imaging (MRI) surveillance protocols for pediatric low-grade gliomas. METHODS Patients aged 0 to 21 yr with pediatric low-grade gliomas, treated between 1990 and 2016 were retrospectively analyzed. The timing of surveillance imaging and radiologic tumor outcomes were extracted, and the effect of patient age, tumor location, histology, and extent of resection as prognostic factors was studied. An algorithm was developed to analyze the detection efficacy and cost of all possible surveillance protocols. RESULTS A total of 517 patients were included with a median follow-up of 7.7 yr (range: 2-25.1 yr) who underwent 8061 MRI scans (mean 15.6 scans per patient). Tumor recurrence was detected radiologically in 292 patients (56.5%), of whom, 143 underwent reoperation. The hazards ratio (HR) of recurrence was higher in patients who underwent biopsy (HR = 3.60; 95% confidence interval (CI): 2.45-5.30; P < .001), subtotal resection (HR = 2.97; 95% CI: 2.18-4.03; P < .001), and near-total resection (HR = 2.03; 95% CI: 1.16-3.54; P = .01), compared to patients with gross total resection (GTR). For all patients, an 8-image surveillance protocol at 0, 3, 6, 12, 24, 36, 60, and 72 mo (total cost: $13 672 per patient) yielded comparative detection rates to the current 15-image protocol ($25 635). For patients who underwent GTR, a 6-image protocol at 0, 3, 9, 24, 36, and 60 mo ($10 254) is sufficient. CONCLUSION Our data suggest that postoperative surveillance of pediatric low-grade gliomas can be effectively performed using less frequent imaging compared to current practice, thereby improving adherence to follow-up, and quality-of-life, while reducing costs.