Thomas Schlossbauer MD, Presenter: Nothing to Disclose

Steven Sourbron PhD, Abstract Co-Author: Nothing to Disclose

Anna Scholz, Abstract Co-Author: Nothing to Disclose

Steffen Kahlert MD, Abstract Co-Author: Nothing to Disclose

Maximilian F. Reiser MD, Abstract Co-Author: Nothing to Disclose

Karin Hellerhoff MD, Abstract Co-Author: Nothing to Disclose

The aim of this study is to evaluate perfusion parameters and segmented tumor volume from dynamic contrast-enhanced breast MRI in the course of neoadjuvant therapy and correlate these findings with histopathological parameters, namely HER2/neu status and estrogen receptor score.

65 women (mean age 47 ± 10 years) with locally advanced breast cancer (mean segmented tumor size 25 ml) had contrast-enhanced MRI (3D FLASH ; TR = 9.1ms, TE = 4.8ms, FA 25°, matrix 256x256 pixels, FOV 350mm, slice thickness 2mm, slices n=32, one pre- and 5 postcontrast series, temporal resolution 90s) before and after chemotherapy. The enhancing part of the lesion was segmented semi-automatically and 5 perfusion parameters were extracted from this ROI: the enhancing volume in ml (SIZE), maximum relative enhancement (MAX), area under the curve (AUC), time-to-peak (TTP), and maximum upslope (MUS). Findings were correlated with histopathologic evaluation, namely estrogen receptor score (ER) and human epidermal growth factor receptor (HER2/neu) status.  

SIZE was reduced significantly in the course of therapy (25ml vs. 5ml, p<0.0001). Perfusion parameters AUC, MAX, MUS significantly decreased (p<0.0001), while TTPsignificantly increased (p<0.0001). There was no significant correlation (p>0.01) in any of the parameters with either ER score or HER2/neu status. Patients with HER2/neu score equal 2+pos. or 3+ showed significantly greater changes in SIZE (p<0.01), MAX (p<0.01) and AUC (p<0.05) compared to lesions with lower HER2/neu score (0 to 2+neg.). The two most sensitive parameters SIZE and MAX were fully uncorrelated (r=0.22). 

With a routine MRI protocol and a semi-quantitative analysis of the signal enhancement curves, useful information about the size and hemodynamic status of a particular tumor under treatment can be extracted. All parameters change under therapy, but the enhancing volume is most sensitive to therapy effects, and differentiates best between the responses of histological subgroups. However, case studies suggest that changes in enhancing tumor volume alone are not sufficient to characterize the response to therapy, and that maximum enhancement must be taken into account.  

Perfusion parameters and segmented tumor size derived from dynamic breast MRI represent complementary parameters and should both be taken into account when evaluating treatment response.

Schlossbauer, T, Sourbron, S, Scholz, A, Kahlert, S, Reiser, M, Hellerhoff, K, Dynamic Breast MRI in the Course of Chemotherapy: Decrease of Standardized Perfusion and Size Parameters in Comparison to Different Histopathologic Characteristics.  Radiological Society of North America 2009 Scientific Assembly and Annual Meeting, November 29 - December 4, 2009 ,Chicago IL. http://archive.rsna.org/2009/8004328.html