Table 4.

Diagnostic performance (on a per-scan basis) for T2-weighted MRI only versus T2-weighted MRI + DWI combined for diagnosing local tumor regrowth after chemoradiotherapy followed by organ-saving treatment

	T2W		T2W + DWI
	R1	R2	R1	R2
Sensitivity (%)	58 (29–84) [7/12]	58 (29–84) [7/12]	75 (43–93) [9/12]	75 (43–93) [9/12]
Specificity (%)	98 (96–99) [418/428]	100 (99–100) [428/428]	97 (99–100) [414/428]	100 (98–100) [426/428]
PPV (%)	41 (19–67) [7/17]	100 (56–100) [7/7]	39 (20–61) [9/23]	82 (48–79) [9/11]
NPV (%)	99 (97–100) [418/423]	98 (97–99) [428/433]	99 (98–100) [414/417]	99 (98–100) [426/429]
Accuracy (%)	97 (94–98) [425/440]	99 (97–100) [435/440]	96 (94–98) [423/440]	99 (97–100) [435/440]
No. of equivocal scores (confidence level 2)	5 [22/440]	9 [40/440]	2 [7/440]	5 [20/440]

Note: Numbers in parentheses are 95 % confidence intervals; numbers in brackets are raw data

R1 reader 1, R2 reader 2, PPV positive predictive value, NPV negative predictive value