Usefulness of 18F-FDG PET/CT for Evaluating Response of Breast Cancer to Neoadjuvant Therapy

Abstract

Neoadjuvant chemotherapy (NACT) was introduced more than four decades ago
for the treatment of locally advanced breast cancer. Accurate assessment of the residual disease after NACT is important for further surgical management. The aim of this study was to document the appearance of 18F-FDG PET/CT after chemotherapy and correlate them with histopathology, to calculate the accuracy of 18F-FDG PET/CT in predicting the size of the residual disease. We undertook a retrospective review of patient data for 38 women who had histologically confirmed malignant tumor with at least 1 site and underwent FDG PET/CT
before and after treatment between January 2016 and December 2017. Anti-treatment and post-treatment findings of both PET/CT, ultrasonic were collected and analyzed according to the pathological results. In our analysis of 38 patients treated with neoadjuvant therapy, after chemotherapy there was reduction in size of all of the measurable masses (38/38,100 % of mass lesions) and in lesion number of 23 cases. And there was a significant decrease of both
diameter (36/38) and number (19/38) of positive lymph node. We took SUV max and SUV mean of lymph node as indicator, and we found that the SUV max showed a decline in 35 cases of breast and in 33 cases of positive lymph node, and the SUV mean showed a decline in 38 cases of breast and in 32 cases of positive lymph node. In conclusion, PET/CT was more accurate in evaluating tumor size than ultrasonic examination, besides, in T2 and T3 stages, SUV max and SUV mean could be an indicator for neoadjuvant therapy.