Table 5.

Changes of mean TGF-β1 ratio during the course of radiation therapy

		Mean of Ratio ± SD
	Time	RP	Non-RP	p value*
RP2	Before RT
(n = 8)	Beginning of RT	0.8 ± 0.2	1.0 ± 0.2	0.019
	Middle of RT	0.8 ± 0.4	0.9 ± 0.4	0.238
	End of RT	0.8 ± 0.2	0.9 ± 0.3	0.346
	2 wks after RT	1.0 ± 0.6	0.9 ± 0.3	0.576
	4 wks after RT	1.6 ± 1.0	0.8 ± 0.3	0.081

Abbreviations: RT, radiation therapy; wks, weeks; RP2, development of grade ≥ 2 radiation pneumonitis

* student's t-test