Dosimetric risk factors for radiation esophagitis in patients with breast cancer following regional nodal radiation

Table 4 Comparisons of esophageal dosimetric parameters between patients without and with grade 2 radiation oesophagitis

Variable	Univariable logistic regression		Stepwise linear regression
	OR (95%CI)	P value	Adjust R2	Std. error	F	P value
Total volume	1.20 (0.72-2.00)	0.48
Dmean	1.44 (1.12-1.85)	< 0.01
Dmax	1.38 (1.09-1.76)	0.01
RV V10	1.02 (0.98-1.06)	0.29
RV V20	1.08 (1.01-1.16)	0.03
RV V30	1.36 (1.13-1.63)	< 0.01
RV V35	1.22 (1.10-1.36)	< 0.01
RV V40	1.36 (1.06-1.75)	0.01
AV V10	1.38 (0.89-2.13)	0.16
AV V20	2.30 (1.14-4.64)	0.02
AV V30	2.97 (1.88-5.69)	< 0.01	0.48	0.48	59.1	< 0.01
AV V35	2.43 (1.45-3.96)	< 0.01	0.51	0.76	33.9	0.03
AV V40	2.52 (1.96-3.60)	0.01

OR: Odds ratio; CI: Confidence interval; RV: Relative volume; AV: Absolute volume.