Resection extent and BRAF V600E mutation status determine postoperative tumor growth velocity in pediatric low-grade glioma: results from a single-center cohort analysis

Purpose Despite excellent long-term overall survival rates, pediatric low-grade gliomas (pLGG) show high variety of clinical behavior regarding progress or senescence post incomplete resection (IR). This study retrospectively analyzes tumor growth velocity (TGV) of pLGG before surgery and after IR to investigate the impact of surgical extent, tumor location and molecular BRAF status on postoperative residual tumor growth behavior. Methods Of a total of 172 patients with pLGG receiving surgical treatment, 107 underwent IR (66%). Fifty-three vs 94 patients could be included in the pre- and post-operative cohort, respectively, and were observed over a mean follow-up time of 40.2 vs 60.1 months. Sequential three-dimensional MRI-based tumor volumetry of a total of 407 MRI scans was performed to calculate pre- and postoperative TGV. Results Mean preoperative TGV of 0.264 cm 3 /month showed significant deceleration of tumor growth to 0.085 cm 3 /month, 0.024 cm 3 /month and −0.016 cm 3 /month after 1st, 2nd, and 3rd IR, respectively (p