Table 1.

Patient characteristics

Characteristic	Total	Osimertinib group		Osimertinib + RT group		χ2	p
		No	%	No	%
Gender
Male	31	23	57.5	8	38.1
Female	30	17	42.5	13	61.9	2.075	0.150
Age (years)
Range	33–74	37–74		33–65
Median	54	51.5		55
< 65	52	32	80.0	20	95.2
≥ 65	9	8	20.0	1	4.8	2.542	0.146
Smoking status
Smoker	13	7	17.5	6	28.6
Never smoked	48	33	82.5	15	71.4	1.007	0.341
Extracranial lesions
Yes	56	37	92.5	19	90.5
No	5	3	7.5	2	9.5	0.075	1.000
Brain metastases
Symptomatic	33	21	52.5	12	57.1
Asymptomatic	28	19	47.5	9	42.9	0.120	0.730
Number of brain metastases
≤ 3	23	15	37.5	8	38.1
> 3	38	25	62.5	13	61.9	0.002	0.964
Leptomeningeal metastases
Yes	27	20	50.0	7	33.3
No	34	20	50.0	14	66.7	1.550	0.213
EGFR mutation
Exon 19 deletion	30	20	50.0	10	47.6
21 L858R	31	20	50.0	11	52.4	0.031	0.860
T790M mutation
Positive	51	33	82.5	18	85.7
Unknown	10	7	17.5	3	14.3	0.104	1.000
Range	0–5	0–4		0–5
Median	1	1		1
0	7	4	10.0	3	14.3
1	34	23	57.5	11	52.4
> 1	20	13	32.5	7	33.3	0.449	0.927
Prior lines of TKI therapy
Range	0–2	0–2		0–1
Median	1	1		1
0	8	4	10.0	4	19.0
1	52	35	87.5	17	81.0
2	1	1	2.5	0	0	1.521	0.628

RT cranial radiotherapy, χ2 Chi-square statistic, EGFR epidermal growth factor receptor, TKI tyrosine kinase inhibitors