Table 1. Characteristics of 79 patients with brain metastases and leptomeningeal metastases.

Characteristics	Brain metastases				Leptomeningeal metastases
	EGFR-TKI naïve	EGFR-TKI treated	Total		EGFR-TKI naïve naivenainaïvenaive	EGFR-TKI treated	Total
Total	24	29	53		5	21	26
Sex
Male	10	17	27		1	11	12
Female	14	12	26		4	10	14
Age
<60 years	11	17	28		3	13	16
≥60 years	13	12	25		2	8	10
Smoking status
No	18	20	38		4	15	19
Yes	6	9	15		1	6	7
Neurological symptoms
No	11	12	23		0	3	3
Yes	13	17	30		5	18	23
Chemotherapy
No	19	6	25		4	6	10
Yes	5	23	28		1	15	16
Local CNS RT
No	23	23	46		5	18	23
Yes	1	6	7		0	3	3
Number of metastasesa
Single	8	1	9		1	4	5
Multiple	16	28	44		4	15	19

^a, two patients with leptomeningeal metastases and EGFR-TKI treatment were negative by MRI but positive by ThinPrep cytologic test. TKI, tyrosine kinase inhibitors; CNS, central nervous system; RT, radiotherapy.