Thirteen were supratentorial lesions (5 high grade, 8 low grade) and 15 were infratentorial lesions (9 high grade, 6 low grade).

• 13例是天幕上的肿瘤（5个是高恶性度，8个是低恶性度）；15例是天幕下的肿瘤（9个是高恶性度，6个是低恶性度）。