[1] Yonsei Univ, Coll Med, Brain Tumor Ctr Severance Hosp, Dept Neurosurg, 50-1 Yonsei Ro, Seoul 120752, South Korea
[2] Catholic Univ Korea, Coll Med, Seoul St Marys Hosp, Dept Neurosurg, 222 Banpo Daero, Seoul 137701, South Korea
[3] Hanyang Univ, Dept Life Sci, 17 Haendang Dong, Seoul 133791, South Korea
[4] Yonsei Univ, Coll Med, Severance Hosp, Dept Radiol, 50-1 Yonsei Ro, Seoul 120752, South Korea