Table 2. Features of the sample groups.

	Training set	Testing set	Total
Number of patients	32	32	64
Age: mean in years (range)	58.4 (32–79)	57.2 (35–76)	(32–79)
Men/women	6/26	7/25	13/51
Total number of noninfiltrative tumors	15	15	30
Total number of tumors with infiltrative or invasive features (tumors may have several infiltrative features)	17	17	34
Cavernous sinus or sagittal sinus infiltration	12	11	23
Bone infiltration	13	10	23
Cortex invasion	1	1	2