***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: Several independent r and omized controlled trials are initiated to investigate whether sentinel lymph node biopsy can be safely omitted in clinical ly node negative breast cancer patients with negative axillary ultrasound findings , who are treated with breast conserving therapy .  A consequence of omitting sentinel lymph node biopsy is absence of pathological lymph node status information . We aim ed to investigate the impact of omitting sentinel lymph node biopsy on adjuvant systemic treatment recommendations .  Data from all consecutive patients with invasive breast cancer and negative axillary ultrasound findings treated with breast conserving therapy and sentinel lymph node biopsy between 2008 and 2012 were collected from a prospect i ve data base . Two methods , Adjuvant ! Online and the Dutch breast cancer guideline 2012 , were used to determine the adjuvant systemic treatment recommendations of every patient . At first , each patient was considered to be lymph node negative , and secondly the patients ’ true pathological lymph node status was used . A total of 303 patients were consecutively included .  Pathological lymph node status was pN0 in 72.3 % , pN0(i+ ) in 12.9 % , pN1mi+ in 5.6 % , pN1 in 7.3 % , and pN2 in 2.0 % of the patients . The decision to recommend  adjuvant systemic treatment  changed due to the pathological lymph node status in 1.0 % of the patients ( 3/303 ) when using Adjuvant ! Online and in 3.6 % ( 11/303 ) when using the 2012 Dutch breast cancer guideline . The impact of the pathological lymph node status on adjuvant systemic treatment recommendations in clinical ly node negative breast cancer patients with negative axillary ultrasound findings treated with breast conserving therapy is limited . The safety of omitting the sentinel lymph node biopsy should be confirmed by the initiated r and omized controlled trials PURPOSE To evaluate magnetic resonance ( MR ) imaging with ultrasmall superparamagnetic iron oxide ( USPIO ) enhancement for preoperative axillary lymph node staging in patients with breast cancer by using histopathologic findings as the st and ard of reference . MATERIAL S AND METHODS MR imaging was performed with a 1.5-T system within 24 - 36 hours after the start of intravenous slow-drip infusion of USPIO in 20 patients with breast cancer who were scheduled for surgery , followed by gadolinium-enhanced MR imaging .  Lymph nodes were staged prospect ively by using newly established criteria , and results were correlated with histologic findings . RESULTS In two patients , preoperative findings led to a change in therapeutic approach , and neoadjuvant chemotherapy was given ; both patients were excluded from statistical analysis . Results of axillary staging with USPIO-enhanced MR imaging were true-positive in nine , true-negative in seven , false-positive in zero , and false-negative in two of 18 patients ( sensitivity , 82 % ; specificity , 100 % ; positive predictive value , 100 % ; second reader , kappa = 1.0 ) . Four hundred five lymph nodes were detected with MR imaging . For first and second readers , respectively , lymph node-based sensitivity was 83 % and 73 % and specificity was 96 % and 97 % ( kappa = 0.68 ) . USPIO as the intravascular contrast agent could not replace gadolinium for assessment of the primary tumor ; however , no clinical ly relevant interaction was seen . Thus , an integrated imaging approach was feasible in all patients . CONCLUSION USPIO-enhanced MR imaging has the potential to become an adjunct to conventional MR imaging of the breast for preoperative assessment of axillary lymph nodes in patients with breast cancer 
    Output:
    
Conclusions The diagnostic performance of some MRI protocol s for excluding axillary lymph node metastases approaches the NPV needed to replace SLNB .
Main Messages• Some axillary MRI protocol s approach the NPV of an SLNB procedure.• Dedicated axillary MRI is more accurate than protocol s also covering the breast.• T1w/T2w protocol s combined with USPIO-enhanced sequences are the most promising sequences