The authors reported the optimal ADC cut-off as 1.118 × 10 − 3 mm2/s with sensitivity and specificity 90.67, and 84.13% respectively. For example, in the study of Aribal et al., 129 patients with 138 lesions (benign n = 63 malignant n = 75) were enrolled. Thirdly and most importantly, the reported ADC threshold values and as well specificity, sensitivity, and accuracy values ranged significantly between studies. Secondly, the studies had different proportions of malignant and benign lesions. Firstly, most reports regarding ADC in several breast cancers and benign breast lesions investigated relatively small patients/lesions samples. However, use of ADC for discrimination BC and benign breast lesions is difficult because of several problems. In addition, according to the literature, ADC is associated with several histopathological features, such as cell count and expression of proliferation markers, in different tumors. It has been shown that malignant tumors have lower values in comparison to benign lesions. Furthermore, restriction of water diffusion can be quantified by apparent diffusion coefficient (ADC). DWI is a magnetic resonance imaging (MRI) technique based on measure of water diffusion in tissues. Numerous studies reported that diffusion-weighted imaging (DWI) has a great diagnostic potential and can better characterize breast lesions than conventional MRI. Therefore, MRI can often not distinguish malignant and benign breast lesions. However, it has a high sensitivity but low specificity. Furthermore, MRI can also predict response to treatment in BC. MRI has been established as the most sensitive diagnostic modality in breast imaging. Magnetic resonance imaging (MRI) plays an essential diagnostic role in breast cancer (BC).

ConclusionĪn ADC threshold of 1.00 × 10 − 3 mm 2/s can be recommended for distinguishing breast cancers from benign lesions. This result was independent on Tesla strength, choice of b values, and measure methods (whole lesion measure vs estimation of ADC in a single area). The calculated ADC values of benign lesions were over the value of 1.00 × 10 − 3 mm 2/s. The mean ADC value of the malignant lesions was 1.03 × 10 − 3 mm 2/s and the mean value of the benign lesions was 1.5 × 10 − 3 mm 2/s. Malignant lesions were diagnosed in 10,622 cases (76.7%) and benign lesions in 3225 cases (23.3%). The acquired 123 studies comprised 13,847 breast lesions. Mean ADC values including 95% confidence intervals were calculated separately for benign and malign lesions. DerSimonian and Laird random-effects models with inverse-variance weights were used without any further correction to account for the heterogeneity between the studies. The meta-analysis was undertaken by using RevMan 5.3 software. The methodological quality of the 123 studies was checked according to the QUADAS-2 instrument. The following data were extracted from the literature: authors, year of publication, study design, number of patients/lesions, lesion type, mean value and standard deviation of ADC, measure method, b values, and Tesla strength. MEDLINE library and SCOPUS database were screened for associations between ADC and malignancy/benignancy of breast lesions up to December 2018. The purpose of the present meta-analysis was to provide evident data about use of Apparent Diffusion Coefficient (ADC) values for distinguishing malignant and benign breast lesions.

Benign findings