Table 2.

Comparison for volumes and dosimetric parameters between first and second scan

2a: No change in simulation technique
		Mean (SD) (min–max)	p-value
GTV (cc)	First scan	276.7(253.8) (4.8–933)	0.001
	Second scan	192.7 (180) (2.4–733)
Lung volume (cc)	First scan	3700 (1085) (1791–6540)	0.064
	Second scan	3833 (1046) (1313–6145)
PTV D95 (%)	First scan	94.99 (4.04) (84–99.7)	0.38
	Second scan	94.52 (4.9) (80–99.7)
Lung V20 (%)	First scan	26 (7.6) (0.8–39)	0.36
	Second scan	25.3 (6.6) (9.7–37)
Mean lung dose (Gy)	First scan	15.1 (3.7) (3–22.5)	0.23
	Second scan	14.7 (3.3)5–21
Heart V40 (%)	First scan	10.2 (13) (0–64)	0.037
	Second scan	7.2 (9.8) (0–45)
Spine maximal dose (Gy)	First scan	39 (8.4) (19.6–50.7)	0.72
	Second scan	39.2 (8.8) (21-52)
2b: With change in simulation technique
		Mean (SD) (min-max)	p-value
GTV (cc)	First scan	165.8 (161) (9.3–480)	0.13
	Second scan	131 (126) (3.3–349)
Lung volume (cc)	First scan	2835.8 (1062) (1613–5300)	0.001
	Second scan	4466 (1250)(2567–6838)
PTV D95 (%)	First scan	92.2 (4.9) (84-98)	0.72
	Second scan	93.3 (6.5) (79-99)
Lung V20 (%)	First scan	30.8 (8.2) (8–37.5)	0.012
	Second scan	27.3 (8) (4–36.5)
Mean lung dose (Gy)	First scan	17.3 (4.4) (5.6–22.6)	0.007
	Second scan	15.3 (3.8) (3–18.8
Heart V40 (%)	First scan	11.1 (14.7) (0–51)	0.014
	Second scan	6.5 (6.7) (0–19)
Spine maximal dose (Gy)	First scan	46.6 (8.4 (31.7–60)	0.028
	Second scan	39.4 (7.9) (26.8–50.3)

GTV, Gross tumor volume; Gy, radiation units in Gray; LungV20, lung volume receiving above 20 Gy; PTV, Planning Target Volume; SD, standard deviation.

D95 volume covered by 95% of the dose; Heart V 40-heart volume receiving dose above 40 Gy. Dose if plan was to the full prescribed dose with the current scan. For p-value Wilcoxon signed-rank test was used.