Leptomeningeal enhancement on preoperative brain MRI in patients with glioblastoma and its clinical impact

Leptomeningeal enhancement (LME) on preoperative brain magnetic resonance imaging (MRI) does not always indicate leptomeningeal seeding (LMS). With Stupp's regimen, authors have treated glioblastoma patients with LME on preoperative brain MRI but here we tried to find the clinical impact of LME.From 2005 to 2015, 290 patients with glioblastoma have been treated with Stupp's regimen at Samsung Medical Center. Among these, 33 patients showed LME on preoperative brain MRI. We compared the clinical outcomes between the patients with or without LME on preoperative brain MRI and analyzed the clinical results according to changes of LME at following MRI.The median survival was 23 months, and 2-year overall survival (OS) and disease-free survival (DFS) rate was 46.3% and 19.6%, respectively. Prognostic factors for OS and DFS were Karnofsky performance status, extent of resection and adjuvant chemotherapy. MGMT promoter methylation status was a significant prognostic factor for DFS. However, LME was not a significant prognostic factor for OS (P = 0.156) or DFS (P = 0.193). Among the 33 patients with LME on preoperative MRI, 21 (63.6%) showed persistent LME at the next MRI. A statistically significant difference in 2-year survival was evident between patients with and without persistent LME (OS, 17.3% and 70.1%, respectively, P = 0.044; DFS, 5.3% and 54.0%, respectively, P = 0.006). The most common pattern of failure was local recurrence. However, patients with persistent LME displayed a higher incidence of LMS than patients without LME.LME on preoperative brain MRI did not affect the clinical results in glioblastoma patients treated with the Stupp's regimen. However, persistence of LME was associated with poor survival and high possibility of LMS. For these patients, the postoperative adjuvant treatment should focus on palliative aim or more aggressive treatment scheme should be followed to overcome the disastrous results.