[MR imaging of the breast before and after neoadjuvant treatment - enhancement characteristics and T 2 signal intensity of breast cancers and breast parenchyma].

PURPOSE

Analysis of enhancement characteristics and T 2 signal intensity (SI) of breast cancers and normal breast parenchyma on MR imaging (MRI) before and after neoadjuvant treatment (NT) to improve the assessment of therapy response.

MATERIALS AND METHODS

Retrospective data analysis of 43 consecutive patients (mean age 49.9 years) with invasive breast cancers (T2 /T3) who received NT. Evaluation of breast MRI before and after NT with assessment of therapy response according to RECIST criteria as well as calculation of the maximum initial enhancement (Enh (max)), delayed enhancement (Enh (post)) and T 2 SI by ROI analyses of breast cancers and breast parenchyma. Comparison of therapy response and enhancement characteristics.

RESULTS

Therapy response on MRI: 16.3 % (n = 7) complete remission (CR (MRT)), 53.5 % (n = 23) partial remission (PR (MRT)), 27.9 % (n = 12) stable disease (SD (MRT)) und 2.3 % (n = 1) progressive disease (PD (MRT)). Breast cancers showed a significant decrease in Enh (max) and T 2 SI as well as a significant increase in Enh (post) after NT (p < 0.01). Not any SI parameter of normal breast parenchyma showed a significant change after NT (p > 0.05). All cases with CR (MRT) had wash out or plateau shape of the SI time curve before NT and showed continuous enhancement thereafter.

CONCLUSION

Breast MRI shows significant changes in enhancement characteristics and T 2 SI of breast cancers after NT, whereas normal breast parenchyma remains unchanged. SI data could possibly help to improve the assessment of therapy response by MRI. Prospective trials with larger study cohorts and MRI monitoring during NT are necessary to validate these results.