Detection of Contralateral Breast Cancer Using Diffusion-Weighted Magnetic Resonance Imaging in Women with Newly Diagnosed Breast Cancer: Comparison with Combined Mammography and Whole-Breast Ultrasound

Abstract

Objective To compare the screening performance of diffusion-weighted (DW) MRI and combined mammography and ultrasound (US) in detecting clinically occult contralateral breast cancer in women with newly diagnosed breast cancer. Materials and Methods Between January 2017 and July 2018, 1148 women (mean age ± standard deviation, 53.2 ± 10.8 years) with unilateral breast cancer and no clinical abnormalities in the contralateral breast underwent 3T MRI, digital mammography, and radiologist-performed whole-breast US. In this retrospective study, three radiologists independently and blindly reviewed all DW MR images (b = 1000 s/mm 2 and apparent diffusion coefficient map) of the contralateral breast and assigned a Breast Imaging Reporting and Data System category. For combined mammography and US evaluation, prospectively assessed results were used. Using histopathology or 1-year follow-up as the reference standard, cancer detection rate and the patient percentage with cancers detected among all women recommended for tissue diagnosis (positive predictive value; PPV 2 ) were compared. Results Of the 30 cases of clinically occult contralateral cancers (13 invasive and 17 ductal carcinoma in situ [DCIS]), DW MRI detected 23 (76.7%) cases (11 invasive and 12 DCIS), whereas combined mammography and US detected 12 (40.0%, five invasive and seven DCIS) cases. All cancers detected by combined mammography and US, except two DCIS cases, were detected by DW MRI. The cancer detection rate of DW MRI (2.0%; 95% confidence interval [CI]: 1.3%, 3.0%) was higher than that of combined mammography and US (1.0%; 95% CI: 0.5%, 1.8%; p = 0.009). DW MRI showed higher PPV 2 (42.1%; 95% CI: 26.3%, 59.2%) than combined mammography and US (18.5%; 95% CI: 9.9%, 30.0%; p = 0.001). Conclusion In women with newly diagnosed breast cancer, DW MRI detected significantly more contralateral breast cancers with fewer biopsy recommendations than combined mammography and US.

Unenhanced Breast MRI With Diffusion-Weighted Imaging for Breast Cancer Detection: Effects of Training on Performance and Agreement of Subspecialty Radiologists

“…However, there is growing interest in exploring the use of unenhanced MRI with DWI as a standalone screening tool for breast cancer detection [ 27 ]. Multiple retrospective studies have included both positive and negative imaging findings to simulate the screening population and assess the potential of unenhanced MRI [ 8 9 10 12 13 14 28 ]. However, some of these studies were enriched with high cancer prevalence (25%–67%) [ 9 10 12 13 14 ].…”

The road to breast cancer screening with diffusion MRI

“…Lesion detection can be achieved from DWI acquired with high b values, which have a higher contrast between breast lesions (which appear bright) and normal parenchyma (dark background). Breast cancer detection using DWI has been shown to be more sensitive than MMG, with the DWI screening approach allowing to detect mammographically occult cancers ( 53 – 55 ) and DWI has been shown to detect significantly more contralateral breast cancers in women with unilateral breast cancer than MMG ( 56 ). High b-values are also useful in decreasing false-positive breast cancer cases ( 57 ).…”