Katja Pinker-Domenig MD, Presenter: Nothing to Disclose

Hubert Bickel MD, Abstract Co-Author: Nothing to Disclose

Wolfgang Bogner MSC, Abstract Co-Author: Nothing to Disclose

Stephan Gruber MD, Abstract Co-Author: Nothing to Disclose

Heidemarie Moosbauer, Abstract Co-Author: Nothing to Disclose

Thomas Hans Helbich MD, Abstract Co-Author: Research Consultant, Siemens AG Research Consultant, Hologic, Inc Research Grant, Siemens AG

To assess radiological tumor response to neoadjuvant chemotherapy (NAC) with a high temporal and spatial resolution MR breast imaging protocol at 3Tesla and to correlate with pathological response.

35 patients (mean age 50.2 years) with histopatholgical verified breast cancer (BIRADS 6) who underwent NAC were included in this prospective IRB approved study. The MRI protocol consisted of a coronal T2-weighted and a coronal combined high temporal and spatial resolution T1-weighted sequence before and after application of a standard dose Gd-DOTA (VIBE with a high temporal resolution of SI 1.7mm isotropic; TA 3.45 min for 17 measurements; FLASH with high spatial resolution of SI 1mm isotropic; TA 2 min). Patients were examined before (baseline) and after 6 cycles of NAC. Tumor response to NAC was assessed using the RECIST 1.1 criteria and classified as complete response (cr), partial response (pr), stable disease (sd) and progressive disease (pd). Correlation of imaging and pathological response as well as under- and overestimation was calculated. The histopathological assessment of tumor response was used as the standard of reference.

There were 29 invasive ductal cancers (IDC) and 6 invasive lobular cancers (ILC). Average tumor size was 45.3 mm. MRI classified 6 as complete response, 24 as partial response, 4 as stable disease,1 as progressive disease. MRI correctly identified treatment response in 88.6%. MRI overestimated response in 5.7% and underestimated response in 5.7%. All over- and underestimated lesions were IDC, no ILC were misclassified. If cr and pr were considered as responder and sd and pd as non-responders MRI at 3T had a sensitivity of 96.8% (CI 0.84%-0.99%) and a specificity 100% (CI 0.51%-100%) in determining reponse to NAC. The PPV was 100% (CI 88.9%-100%) and the NPV was 80% (CI 38%-96%).

In conclusion high resolution MRI of the breast at 3 Tesla using a high resolution imaging protocol allows accurate assessment of response to NAC, especially in ILC.

3T MRI is very accurate in assessment of treatment response and thus facilitates optimal planning of surgical treatment.

Pinker-Domenig, K, Bickel, H, Bogner, W, Gruber, S, Moosbauer, H, Helbich, T, Assessment of Response to Neoadjuvant Chemotherapy with High Resolution MRI at 3T: Correlation with Pathological Response.  Radiological Society of North America 2012 Scientific Assembly and Annual Meeting, November 25 - November 30, 2012 ,Chicago IL. http://archive.rsna.org/2012/12034275.html