Role of ¹⁸F-fluorodeoxyglucose positron-emission tomography/computed tomography in the evaluation of early response to neoadjuvant chemotherapy in patients with locally advanced triple-negative breast cancer

Response evaluation in locally advanced breast cancer is done through different methods ranging from clinical examination to magnetic resonance imaging, however evaluation with positron-emission tomography/computed tomography (PET/CT) in now being incorporated for the response evaluation. The aim of the present study is to correlate response to neoadjuvant chemotherapy (NACT) with PET/CT scan. The present study is a retrospective analysis of 30 locally advanced, triple-negative breast cancer patients. PET/CT scan was done pretreatment and post three and six cycles of NACT and was correlated with pathologic complete response (pCR). Responding disease was considered when there was at least a 50% reduction in the longest diameter. The median pretreatment size of the breast lesion in CT scan was 3.9 ± 2.3 cm (2-12 cm) and maximum standardized uptake value (SUVmax) on PET/CT was 8.5 ± 5.5 (2.9-24). Among the responders, the median decrease in size of lesion was 3.2 ± 1.3 cm and median reduction in SUV of the tumor among was −8.1 ± 5.4 and was statistically significant when compared with nonresponders (P < 0.001). CT scan has 66% accuracy and PET has 82% accuracy at post three cycles NACT in predicting the pathological response. PET/CT had higher sensitivity and specificity when compared with CT findings alone in response evaluation. PET/CT scan can be considered as a sensitive tool for predicting pCRs and further larger trials are required to establish these findings. (author)