The role of PET CT to evaluate the response to neoadjuvant chemotherapy in advanced breast cancer: comparison with ultrasonography and magnetic resonance imaging

Abstract

Background: Recently PET is emerged as a method to estimate the response of neoadjuvant chemotherapy (NAC) in advanced breast cancer. This study is aimed to estimate the predictive role of PET CT and other imaging modalities (ultrasound, MRI) through NAC.

Methods: PET CT was acquired before and after NAC from 41 patients. Pathologic results were classified as pathological complete response (pCR) and non-pCR. The results of clinical responses were assessed with imaging indexes (postTx, postchemotherapy size or peak standardized uptake values (pSUV); delta, the size difference between treatment; RR, reduction rate of tumor size or pSUV), and they were compared with pathologic results.

Results: Seven patients (17.1%) showed pCR. As a result of comparison of the image index, all image indexes of MRI were predictive for pCR (P < 0.05). In contrast, only delta and RR of US, RR of PET CT were significant. The area under curve of delta and RR in MRI were higher (0.91, 0.90) than US (0.83, 0.80) and PET CT (0.62, 0.72). The MRI is superior to the US or PET CT.

Conclusions: We have concluded that the MRI is better than PET CT for monitoring the effect of NAC in advanced breast cancer.