Digital Breast Tomosynthesis Diagnostic Although mammography, DBT, and US are reliable for determining tumor size at diagnosis [11-15], changes within the tumor secondary to NAC may be difficult to evaluate after treatment is initiated. It is well known that tumoral changes related to necrosis, fragmentation, and fibrosis make it difficult for mammography, DBT, and US to accurately determine residual tumor burden [43,44]. In a retrospective study of 445 patients who underwent NAC, mammography was 94% sensitive and 50% specific for predicting residual disease in the breast. In cases presenting as mass lesions, 95% of masses decreased in mammographic size with treatment. However, there was correlation between mammographic size and surgical pathology in only 60% of cases [45]. One study found that if >50% of the margin of the primary lesion was mammographically visible at baseline, posttreatment mammographic imaging was a reliable tool for determining lesion size [28,46]. In a study of 56 patients, mammography was 79% sensitive and 77% specific in predicting residual disease after therapy, performing better than clinical breast examination [47]. The extent of calcifications on mammography after therapy does not correlate well with residual tumor burden and is overestimated in up to 45% of patients [48-50]. Therefore, it is not a reliable marker of remaining viable tumor. In a study including 139 patients with baseline mammographic calcifications, residual calcifications were present on all posttreatment mammograms [45]. Estrogen receptor (ER)-positive tumors are more likely than ER-negative tumors to have residual malignant calcifications on mammography after treatment, whereas triple-negative tumors are the least likely to have residual malignant calcifications after therapy, suggesting that different tumor subtypes may warrant different approaches [48,51].
Monitoring Response to Neoadjuvant Systemic Therapy for Breast Cancer. Digital Breast Tomosynthesis Diagnostic Although mammography, DBT, and US are reliable for determining tumor size at diagnosis [11-15], changes within the tumor secondary to NAC may be difficult to evaluate after treatment is initiated. It is well known that tumoral changes related to necrosis, fragmentation, and fibrosis make it difficult for mammography, DBT, and US to accurately determine residual tumor burden [43,44]. In a retrospective study of 445 patients who underwent NAC, mammography was 94% sensitive and 50% specific for predicting residual disease in the breast. In cases presenting as mass lesions, 95% of masses decreased in mammographic size with treatment. However, there was correlation between mammographic size and surgical pathology in only 60% of cases [45]. One study found that if >50% of the margin of the primary lesion was mammographically visible at baseline, posttreatment mammographic imaging was a reliable tool for determining lesion size [28,46]. In a study of 56 patients, mammography was 79% sensitive and 77% specific in predicting residual disease after therapy, performing better than clinical breast examination [47]. The extent of calcifications on mammography after therapy does not correlate well with residual tumor burden and is overestimated in up to 45% of patients [48-50]. Therefore, it is not a reliable marker of remaining viable tumor. In a study including 139 patients with baseline mammographic calcifications, residual calcifications were present on all posttreatment mammograms [45]. Estrogen receptor (ER)-positive tumors are more likely than ER-negative tumors to have residual malignant calcifications on mammography after treatment, whereas triple-negative tumors are the least likely to have residual malignant calcifications after therapy, suggesting that different tumor subtypes may warrant different approaches [48,51].