Table 3.

Multivariate analysis for radiation necrosis and symptomatic radiation necrosis in patients with brain metastases

	Radiographic RN		Symptomatic RN
	HR (95% CI)	P-value	HR (95% CI)	P-value
ABT
Yes	0.45 (0.21–0.95)	0.036	0.17 (0.03–0.88)	0.035
No	–		–	–
Primary histology
Lung	2.22 (0.79–6.23)	0.128	8.46 (0.92–77.93)	0.060
Breast	0.68 (0.19–2.48)	0.558	1.92 (0.18–20.37)	0.590
Melanoma	0.92 (0.30–2.88)	0.891	2.87 (0.31–26.32)	0.351
RCC/GI/other	–	–	–	–
Extracranial metastases
Yes	0.62 (0.28–1.34)	0.221	1.14 (0.25–5.17)	0.864
No	–	–	–	–
Prescription IDL
>80	1.78 (0.85–3.72)	0.125
≤80	–	–
CTV volume
≤4	–	–
4–14	2.47 (0.61–10.03)	0.207
>14	4.29 (1.13–16.19)	0.032
Resected lesion
Yes	1.92 (0.30–12.37)	0.492
No	–	–
ECOG performance status
0			0.49 (0.16–1.45)	0.195
1			0.99 (0.40–2.45)	0.987
2+			–	–
Active systemic disease
Yes			0.42 (0.07–2.54)	0.345
No			–	–
GPA
0–2.5			0.51 (0.14–1.84)	0.307
3.0–4.0			–	–
Number of BM
>1			1.36 (0.45–4.07)	0.585
1			–	–
Gender
Male			2.30 (0.96–5.52)	0.062
Female			–	–

Bold p values denotes statistical significant, p < 0.05

RN radiation necrosis, HR hazard ratio, CI confidence interval, ABT angiotensin blockade therapy, RCC renal cell carcinoma, GI gastrointestinal, IDL isodose line, CTV clinical target volume, ECOG eastern cooperative oncology group, GPA graded prognostic assessment, BM brain metastases