Magnetic resonance imaging with apparent diffusion coef f icient histogram analysis: evaluation of luminal type breast cancer prior to neoadjuvant chemotherapy
To determine response prior to neoadjuvant chemotherapy (NAC) in patients with luminal type breast cancer by using magnetic resonance imaging (MRI) apparent diffusion coeff icient (ADC) histogram analysis.
Methods:
Fifty-seven patients with luminal type breast cancer conf irmed by core needle biopsy underwent MRI (including diffusion-weighted imaging sequence) before NAC. Surgery was performed after NAC. Seventeen patients were responders. ADC histogram parameters were recorded
including mean
minimum
standard deviation
maximum
10%
25%
50%
75%
and 90% percentiles
skewness and kurtosis. Inter-observer and intra-observer agreement were analyzed using intraclass correlation coeff icient (ICC). ADC histogram parameters between responders and non-responders were compared using an independent sample t test. The receiver operatingcharacteristic (ROC) curve was used to evaluate the diagnostic performance of ADC histogram parameters in the response prediction.
Results:
The inter-observer ICCs (0.089~0.845) of the ADC histogram parameters were lower than that of the intra-observer (0.306~0.916). The agreement of minimum
10%
25% and 50% were excellent. The minimum
10% and 25% of responders were (0.540.36)10
-3
(0.900.23)10
-3
and (1.020.23)10
-3
mm
2
/s. The minimum
10% and 25% of non-responders were (0.290.28)10
-3
(0.710.20)10
-3
and (0.850.19)10
-3
mm
2
/s. The minimum
10% and 25% of responders were higher than non-responders (
P
<0.05)
and the area under curve (AUC) of the 10% percentile was the largest (0.746). When a cut-off value of 0.74610
-3
mm
2
/s in 10% percentile was used
the sensitivity of 82.35% and specif icity of 65.00% were achieved. However
the diagnostic performance of 10% percentile was not signif
icantly higher than 25% (AUC was 0.724
P
=0.505).
Conclusion:
In patients with luminal type breast cancer
the ADC histogram analysis was useful in the response prediction prior to NAC
and 10% and 25% percentiles had better diagnostic performance and excellent agreement.