Contrast-enhanced US and MRI for assessing the response of breast cancer to neoadjuvant chemotherapy

PurposeTo evaluate the response of breast cancers to neoadjuvant chemotherapy (NAC) with second-generation contrast-enhanced ultrasound (CEUS) and magnetic resonance (MR).Materials and MethodsWe studied 16 women aged 33–74 years (mean, 53 years; median, 38 years) with locally advanced breast carcinoma or large operable breast cancer (>2 cm; T2–T4, N0–N3, M0) that had been detected by mammography, conventional ultrasonography, and biopsy. CEUS (with SonoVue, 5 ml) and MR (with Gd-DTPA; 0.2 mM/kg) were performed under blinded conditions before, during, and after 6–8 cycles of NAC. Lesions were measured and time/signal intensity (T/SI) curves were calculated during both the examinations. The data obtained were analyzed in light of the results of surgical pathology.ResultsSix patients had complete responses manifested by the disappearance of enhancement at both CEUS and MR. Six others had partial responses (reduction of lesion enhancement >50%). In 5/6, T/SI curves obtained with CEUS and MR were both indicative of malignancy (flat curves at CEUS, type I curves at MR); the sixth had a discontinuous curve at CEUS and a type II curve at MR. Four patients had lesional enhancement reductions of <50%. In 3, concordant pictures emerged from the analysis of T/SI curves (discontinuous curves in CEUS, type II and III curves in MR); the fourth had a flat CEUS curve and a type I MR curve. Responses to NAC classified on the basis of MR and CEUS findings showed good correlation with the pathological response.ConclusionsT/SI curves recorded during CEUS correlate with those obtained during MR and may be a valid index of response to the therapy.