337P - Comparison of fused diffusion-weighted imaging using unenhanced MRI and abbreviated post-contrast-enhanced MRI in patients with breast cancer

Background

To determine the percentage of breast cancers detectable by fused diffusion-weighted imaging (DWI) using unenhanced magnetic resonance imaging (MRI) and abbreviated post-contrast-enhanced MRI.

Methods

Between October 2016 and October 2017, 194 consecutive women (mean age, 54.2 years; age range, 28-82 years) with newly diagnosed unilateral breast cancer who underwent preoperative 3.0 T breast MRI with DWI were evaluated. Both fused DWI and abbreviated MRI images were independently reviewed by two radiologists for the detection of index cancer (which showed the most suspicious findings in both breasts), location, lesion conspicuity, lesion type, and lesion size. Moreover, the relationship between cancer detection and histopathological results of surgical specimens were evaluated.

Results

Index cancer detection rates were comparable between fused DWI and abbreviated MRI (radiologist 1: 174/194 [89.7%] vs. 184/194 [94.8%], respectively, P = 0.057; radiologist 2: 174/194 [89.7%] vs. 183/194 [94.3%], respectively, P = 0.092). In both radiologists, abbreviated MRI showed a significantly higher lesion conspicuity than fused DWI (radiologist 1: 9.37 ± 2.24 vs. 8.78 ± 3.03, P < 0.001; radiologist 2: 9.16 ± 2.32 vs. 8.39 ± 2.93, P < 0.001). The κ value for the interobserver agreement of index cancer detection was 0.67 on fused DWI and 0.85 on abbreviated MRI. For lesion conspicuity, the intraclass correlation coefficients were 0.72 and 0.82 on fused DWI and abbreviated MRI, respectively. Among the histopathological factors, tumor invasiveness was associated with cancer detection on both fused DWI (P = 0.011) and abbreviated MRI (P = 0.004, radiologist 1), lymphovascular invasion was associated with cancer detection on abbreviated MRI (P = 0.032, radiologist 1), and necrosis was associated with cancer detection on fused DWI (P = 0.031, radiologist 2).

Conclusions

Index cancer detection was comparable between fused DWI and abbreviated MRI, although abbreviated MRI showed a significantly better lesion conspicuity.

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

The author.

Funding

Has not received any funding.

Disclosure

The author has declared no conflicts of interest.