In breast cancer, interest in technetium-99m (Tc-99m) sestamibi-based therapy monitoring is increasing owing to the growing use of Tc-99m-sestamibi-based molecular breast imaging. In the present... Show moreIn breast cancer, interest in technetium-99m (Tc-99m) sestamibi-based therapy monitoring is increasing owing to the growing use of Tc-99m-sestamibi-based molecular breast imaging. In the present meta-analysis of 529 patients, Tc-99m-sestamibi planar imaging showed low sensitivity for predicting a pathologic nonresponse to neoadjuvant chemotherapy. In contrast, Tc-99m-sestamibi imaging performed during treatment seemed highly sensitive for the prediction of nonresponse. New tools incorporating quantitative single photon emission computed tomography/computed tomography need to be explored.Background: Interest in technetium-99m (Tc-99m)-sestamibi imaging for neoadjuvant chemotherapy (NAC) response monitoring in locally advanced breast cancer (LABC) is increasing but remains matter of discussion. The present study conducted a meta-analysis of the diagnostic performance of Tc-99m-sestamibi to predict pathologic nonresponse to NAC for primary LABC. Materials and Methods: A systematic data search was performed. Studies with a minimum of 10 LABC patients that had evaluated Tc-99m-sestamibi imaging for NAC nonresponse using conventional planar scintimammography, breast-specific gamma-imaging, and/or single photon emission computed tomography/computed tomography (SPECT/CT) were included. The histopathologic findings were the reference standard. The meta-analysis was performed using a mixed logistic regression model. Results: The search revealed 14 eligible studies with 529 patients. Of the 14 studies, 11 had evaluated scintimammography and 3 breast-specific gamma-imaging. No studies examining SPECT or SPECT/CT were found. The overall estimated pooled sensitivity, specificity, and positive and negative likelihood ratios of Tc-99m-sestamibi imaging to predict nonresponsiveness to NAC were 70.3% (95% confidence interval [CI], 56.5%-81.3%%), 90.1% (95% CI, 77.5%-96.0%), 7.13 (95% CI, 3.08-16.53), and 0.33 (95% CI, 0.22-0.49), respectively. Only 3 studies (107 patients) evaluated Tc-99m-sestamibi imaging during NAC, reported an estimated pooled sensitivity of 87% (95% CI, 72%-100%) and specificity of 93% (95% CI, 85%-100%). Conclusion: Only planar Tc-99m-sestamibi imaging has been investigated for NAC nonresponse in LABC but showed low sensitivity to predict pathologic nonresponse. However, most studies focused on the prediction of pathologic complete response after NAC. Although experience is limited, Tc-99m-sestamibi uptake during NAC seems highly sensitivity for the prediction of nonresponsiveness. Features such as SPECT/CT imaging, standardized quantification, relation to tumor subtypes, and proper timing have been insufficiently evaluated and require further investigation. (C) 2017 Elsevier Inc. All rights reserved. Show less