Table 1. Delineated volumes, overlapping clinical target volume and concordance indexes.

	MR images	Mean±SD	Range
Gross tumour	T1PREGTV	37 ± 26	2–94
Volume (cm3)	T1POSTGTV	39 ± 39	7–178
CTV (cm3)	T1PRECTV	248 ± 88	97–473
	T1POSTCTV	254 ± 101	138–501
	T2PRECTV	139 ± 68	24–254
	T2POSTCTV	78 ± 59	15–236
Overlapping CTVs (cm3)	T1PRE ∩ T1POST	202 ± 73	92–353
	T2PRE ∩ T2POST	61 ± 44	3–153
	T1PRE ∩ T2PRE	122 ± 59	24–219
	T1POST ∩ T2PRE	118 ± 54	24–196
Concordance index (CTVs)	T1PRE vs T1POST	0.67 ± 0.09	0.52–0.88
	T2PRE vs T2POST	0.39 ± 0.20	0.09–0.75
	T1PRE vs T2PRE	0.45 ± 0.16	0.15–0.73
	T1POST vs T2PRE	0.44 ± 0.17	0.14–0.73
Concordance index (GTVs)	T1PRE vs T1POST	0.37 ± 0.15	0.08–0.60

GTV, gross target volume; CTV, clinical target volume; SD, standard deviation.