[1] Chengdu Fifth Peoples Hosp, Dept Neurosurg, Chengdu, Peoples R China
[2] Sichuan Prov Matern & Child Hlth Care Hosp, Affiliated Womens & Childrens Hosp, Chengdu Med Coll, Dept Obstet, Chengdu, Sichuan, Peoples R China
[3] Hebei Yanda Hosp, Dept Neurosurg, Langfang, Peoples R China
[4] Tianjin Med Univ, Canc Inst & Hosp, Natl Clin Res Ctr Canc, Tianjins Clin Res Ctr Canc,Key Lab Canc Prevent &, Tianjin, Peoples R China
[5] Tianjin Med Univ, Dept Grad Sch, Tianjin, Peoples R China