Evaluation of Neoadjuvant Chemotherapy Response with Dynamic Contrast Enhanced Breast Magnetic Resonance Imaging in Locally Advanced Invasive Breast Cancer

Abstract

Objective: The reliability of traditional methods such as physical examination, ultrasonography (US) and mammography is limited in determining the type of treatment response in patients with neoadjuvant chemotherapy (NAC) application for locally advanced breast cancer (LABC). Dynamic contrast-enhanced magnetic resonance imaging (MRI) is gaining popularity in the evaluation of NAC response. This study aimed to compare NAC response as determined by dynamic contrast-enhanced breast MRI in patients with LABC to histopathology that is the gold standard; and evaluate the compatibility of MRI, mammography and US with response types. Materials and Methods:The US, mammography and MRI findings of 38 patients who received NAC with a diagnosis of locally advanced breast cancer and surgical treatment were retrospectively analyzed and compared to histopathology results. Type of response to treatment was determined according to the "Criteria in Solid Tumors Response Evolution 1.1" by mammography, US and MRI criteria. The relationship between response types as defined by all three imaging modalities and histopathology were evaluated, and the correlation of response type as detected by MRI and pathological response and histopathological type of breast cancer was further determined. For statistical analysis, the chi-square, paired t test, correlation and kappa tests were used. Results:There is a statistical moderate positive correlation between response type according to pathology and MRI (kappa: 0.63). There was a weak correlation between response type according to mammography or US and according to pathology (kappa: 0.2). When the distribution of treatment response by MRI is stratified according to histopathological types, partial response was higher in all histopathological types similar to the type of pathologic response. When compared with pathology MRI detected treatment response accurately in 84.2% of the patients. Conclusion:Dynamic contrast-enhanced breast MRI appears to be a more effective method than mammography or US in the evaluation of response to neoadjuvant chemotherapy. MRI evaluation of LABC is accepted as the appropriate radiological approach.

Strain wave elastography in response assessment to neo-adjuvant chemotherapy in patients with locally advanced breast cancer

“…However, factors like unavailability of dedicated centers, high cost of contrast agents and limited expertise have restricted widespread use of such modalities. [19][20][21][22][23][24] It has also been well known that malignant breast tissue is generally harder than the normal breast when subjected to clinical palpation. Elastography has been successfully used in the differentiation of benign and malignant breast lesions.…”

“…As alterations in stiffness parameters in responding LABC patients (good responders) directly reflect the microscopic alterations (fibrosis) in the tumor tissue, strain wave elastography provides a stark contrast between patients responding well (good responders) and responding poorly to neo-adjuvant chemotherapy. 8,10,17,19,20,26,27 In our experience, this is the only study of LABC patients receiving a single chemotherapeutic regimen in which strain wave elastographic measurements were employed as a predictor of chemo response.…”

“…Another limitation of the study is the lack of comparison with response assessed with other available imaging modalities. [19][20][21][22][23][24] A study comprising of comprehensive multimodality response evaluation in a large number of patients before and after each cycle of chemotherapy may provide a better clue to a single or a group of imaging modalities with the best diagnostic performance.…”

The Role of Magnetic Resonance Imaging in Surgical Decision Making of Suspicious Breast Lesions in Dense Breast

“…In current study, MRI findings of five patients post neoadjuvant therapy "NAT" (only one patient with full response, two cases with partial response and two cases with stable disease. Gezer and Colleagues [14] , have reported that MRI identified type of NAC response correctly in 32 (84.2%) of 38 patients as compared to pathology. Dynamic contrast-enhanced breast MRI seems to be of great efficiency in comparison with mammography or US in the assessment of NAC response.…”