Can unenhanced MRI of the breast replace contrast-enhanced MRI in assessing response to neoadjuvant chemotherapy?

BACKGROUND: The goals of neoadjuvant chemotherapy (NAC) are to reduce tumor volume and to offer a prognostic indicator in assessing treatment response. Contrast-enhanced magnetic resonance imaging (CE-MRI) is an established method for evaluating response to NAC in patients with breast cancer. PURPOSE: To validate the role of unenhanced MRI (ue-MRI) compared to CE-MRI for assessing response to NAC in women with breast cancer. MATERIAL AND METHODS: Seventy-one patients with ongoing NAC for breast cancer underwent MRI before, during, and at the end of NAC. Ue-MRI was performed with T2-weighted sequences with iterative decomposition of water and fat and diffusion-weighted sequences. CE-MRI was performed using three-dimensional T1-weighted sequences before and after administration of gadobenate dimeglumine. Two blinded observers rated ue-MRI and CE-MRI for the evaluation of tumor response. Statistical analysis was performed to compare lesion size and ADC values changes during therapy, as well as inter-observer agreement. RESULTS: There were no statistically significant differences between ue-MRI and CE-MRI sequences for evaluation of lesion size at baseline and after every cycle of treatment ( P > 0.05). The mean tumor ADC values at baseline and across the cycles of NAC were significantly different for the responder group. CONCLUSION: Ue-MRI can achieve similar results to CE-MRI for the assessment of tumor response to NAC. ADC values can differentiate responders from non-responders.

Role of breast MR imaging for predicting malignancy of histologically borderline lesions diagnosed at core needle biopsy: prospective evaluation.

PURPOSE: To prospectively determine the diagnostic performance of breast magnetic resonance (MR) imaging in predicting the malignancy of breast lesions classified as borderline at core needle biopsy (CNB). MATERIALS AND METHODS: This prospective study was approved by the local ethics committee, and all patients provided written informed consent. Between February 2007 and October 2009, 193 patients underwent ultrasonography (US)-guided CNB. Thirty-two lesions in 32 patients were classified as "borderline" ("lesions of uncertain malignant potential" according to the United Kingdom National Health Service Breast Screening program or those that are "probably benign" according to the Breast Imaging Reporting and Data System [BI-RADS] lexicon) at pathologic examination and were evaluated. All 32 patients underwent contrast agent-enhanced breast MR imaging 1-3 weeks after CNB; surgical biopsy was performed within 60 days of MR imaging. Results were compared with histologic findings. Sensitivity, specificity, accuracy, and positive and negative predictive values were calculated. RESULTS: Findings from surgical biopsy confirmed the diagnosis of seven atypical ductal hyperplasia lesions, four atypical lobular hyperplasia (ALH) lesions, five papillary lesions, two fibroepithelial lesions, three radial scars, three lobular carcinomas in situ, three ductal carcinomas in situ (DCIS), four invasive ductal carcinomas, and one invasive lobular carcinoma. With regard to malignancy, breast MR imaging helped correctly classify 22 of the 32 lesions as negative and seven as positive. Two of the lesions confirmed to be ALH were incorrectly classified as suspicious (BI-RADS category IV; false-positive finding), whereas one small DCIS was incorrectly classified as nonsuspicious (BI-RADS category II; false-negative finding). The sensitivity, specificity, accuracy, and positive and negative predictive values for the correct demonstration of malignancy at MR imaging were 88% (seven of eight lesions), 92% (22 of 24 lesions), 91% (29 of 32 lesions), 78% (seven of nine lesions), and 96% (22 of 23 lesions), respectively. CONCLUSION: Breast MR imaging can improve the evaluation of lesions classified as borderline at CNB. In cases of nonsuspicious enhancement or no enhancement at breast MR imaging, follow-up rather than surgical biopsy might be performed.

High-intensity focused ultrasound in breast pathology: non-invasive treatment of benign and malignant lesions.

Breast neoplasms are one of the leading causes of morbidity and mortality in women. Even if surgery is the treatment of choice, other forms of less invasive radical treatment are desirable. High-intensity focused ultrasound is already established as a valid non-invasive technique that ensures tumor ablation in various organs. The use of ultrasound or magnetic resonance guidance allows having some advantages such as the capability to treat tumors in moving organs or the possibility to have a real-time monitoring of the temperature increase. The aim of this paper is to report the use of high-intensity focused ultrasound technique with ultrasound and magnetic resonance guidance for the ablation of breast tumors, including both benign and malignant lesions.

Effect of preoperative breast magnetic resonance imaging on surgical decision making and cancer recurrence rates.

PURPOSE: To evaluate breast magnetic resonance imaging (MRI) for cancer staging and surgical planning in patients with known breast cancer, and to evaluate recurrence rates at long-term follow-up. METHODS AND MATERIALS: Institutional review board approval and patient consent were obtained. Preoperative MRI with 0.1 mmol/kg gadobenate dimeglumine (MultiHance) was performed in 203/274 women with confirmed breast cancer. The sensitivity, accuracy, and positive predictive value of MRI compared with mammography/ultrasound for malignant lesion detection were calculated, and the effect of MRI on surgical decision making evaluated. The cancer recurrence rate was determined for 172 patients with available 2- to 8-year follow-up data. RESULTS: Mammography/ultrasound detected 229 suspicious lesions. Breast MRI detected 159 additional lesions in 48/203 (23.6%) patients; of which 110/110 were correctly classified as malignant and 28/49 as benign, giving sensitivity, accuracy, and positive predictive values for malignant lesion detection of 100% (110/110), 86.8% (138/159), and 84.0% (110/131), respectively. MRI revealed unsuspected multifocal, multicentric, and synchronous contralateral lesions in 7/48, 16/48, and 16/48 patients, respectively, and pectoralis muscle infiltration in 3/38 patients. In 6/48 women, MRI revealed lesions not seen on conventional imaging (n = 5) or discounted suspected multifocal disease (n = 1). Therapy was changed for 50/203 (24.6%) patients: 38 patients underwent more extensive surgery and 12 less extensive surgery. Six (3.5%) recurrences occurred, in all cases at >4 years. CONCLUSION: Breast MRI positively affects patient management and is recommended for mapping tumor extent in patients with newly diagnosed cancer. The cancer recurrence rate at long-term follow-up after MRI is low.