Optimized Parameters of Diffusion-Weighted MRI for Prediction of the Response to Neoadjuvant Chemoradiotherapy for Locally Advanced Rectal Cancer

Table 3

Diagnostic performance of ADC-related parameters.

	AUC (95% CI)	Cutoff value	Sensitivity (%)	Specificity (%)	PPV (%)	NPV (%)
Pre-ADC (b = 800)	0.419 (0.304–0.534)	0.87 × 10^−3 mm^2/s	33	41	31	43
Post-ADC (b = 800)	0.692 (0.496–0.724)	1.01 × 10^−3 mm^2/s	41	65	51	64
ΔADC (b = 800)	0.879 (0.811–0.946)	0.232 × 10^−3 mm^2/s	79	72	66	53
Percentage of ADC increase (b = 800)	0.957 (0.92–0.993)	29.10%	87	91	69	76
Pre-ADC (b = 1000)	0.411 (0.295–0.527)	1.03 × 10^−3 mm^2/s	41	37	41	45
Post-ADC (b = 1000)	0.537 (0.418–0.655)	1.30 × 10^−3 mm^2/s	43	64	74	47
ΔADC (b = 1000)	0.866 (0.789–0.942)	0.335 × 10^−3 mm^2/s	74	56	47	69
Percentage of ADC increase (b = 1000)	0.893 (0.822–0.965)	28.67%	83	86	51	67

CI: confidence interval; PPV: positive predictive value; NPV: negative predictive value.