Table 1.

Variables

Variable number	Factor	Values
x1	Gender	Male = 1, female = 0
x2	Age	32–83 years
x3	Pathological type of primary lesion	1 = adenocarcinoma, 2 = squamous cell carcinoma, 3 = other
x4	Number of metastases	1–3
x5	Sum of tumor diameters before treatment	0.7–7.1 cm
x6	Sum of peritumoral edema diameters before treatment	1.1–11.5 cm
x7	Maximum value of sum of metastasis diameters	1.2–11.7 cm
x8	Time of appearance of maximum value of sum of metastasis diameters	0–30 months
X9	Presence of radiological tumor progression during brain metastasis treatment	0 = not present, 1 = present
x10	Maximum value of sum of peritumoral edema diameters	0–15.4 cm
x11	Time of appearance of maximum value of sum of peritumoral edema diameters	0–30 months
x12	Number of appearances of Cho/Cr > 2	1–3
x13	Number of island (yu‐yuan) signs	1–3
x14	Number of appearances of high‐signal ring in T2 FLAIRs	1–3
y	Survival period	6–30 + months

Zero months in x8 and x11 represent data prior to treatment. FLAIR, fluid‐attenuated inversion recovery.