Author(s)

Yun Xi, Min Zhang, Rui Guo, Miao Zhang, Jiajia Hu, Biao Li

Department of Nuclear Medicine, Ruijin Hospital, Shanghai, China..

Purpose: To evaluate the accuracy and the predictive value of ¹⁸F-FDG PET or PET/CT in the assessment of neoadjuvant chemotherapy (NAC) in locally advanced breast cancer by meta-analysis. Materials and Methods: Relevant studies were identified by systematic searches of PUBMED and COCHRANE databases, published in English. To ensure homogeneity of all included studies, selection criteria were established and all the studies were scored according to Quality Assessment of Diagnostic Accuracy Studies (QUADAS) criteria. Meta-analysis was done on the diagnostic performance data from eligible studies. Draw funnel plots to explore the publication bias. Draw forest plots to exclude abnormal data(s). Use Spearman correlation coefficients p, likelihood ratio x² test and I² index in order to indicate heterogeneity. Estimate and compare the weighted summary sensitivities (SEs), specificities (SPs), diagnostic odds ratios (DORs), and summary receiver operating characteristic (SROC) curves of PET and other examinations (measuring the size of tumor). Subgroup analyses were performed to identify heterogeneity potential sources. Do Z test to find significant difference between each results. Results: 27 groups of data in 19 eligible studies were included with a total of 1164 subjects evaluated by ¹⁸F-FDG PET or PET/CT and 291 ones evaluated by other examinations. Funnel plots showed the existence of publication bias. Spearman correlation coefficients p, likelihood ratio x² test and I² index explored the heterogeneity. The Results of the Weighted Summary: SE_PET was significantly higher than SE_D [83.7% (329/393) vs. 59.0% (98/166), p < 0.001], SP_PET was significantly higher than SP_D [66.8% (512/766) vs. 40.8% (51/125), p < 0.001], DOR_PET was significantly higher than DOR_D (14.02 vs. 1.29, p < 0.05). The results show that FDG-PET was more accurate in assessment NAC efficiency. Draw SROC curves with Metadisc 14.0 and caculate results showed AUC_PET and Q*_PET were both significantly higher than AUC_D and Q*_D (AUCs 0.8838 vs. 0.6046; Q*s 0.8143 vs. 0.5788, p < 0.001), which confirmed the advantage of FDG-PET. Subgroup analysis showed that performing FDG-PET after the 1^st or 2^nd cycle of NAC was a litter better than later with higher SE (p = 0.083). Standardized uptake value (SUV) reduction rate between 40% and 45% as FDG-PET response threshold value was used for its highest SP (p = 0.01), while no significant difference was found comparing SEs and DORs (p > 0.05). Trend of higher SE and lower SP were found at ER negative breast cancers than ER positive ones (SEs 93.94% vs. 83.33%; SPs 35.76% vs. 62.24%), though Z test did not find significant difference (p > 0.05). Conclusion: This meta-analysis showed that FDG-PET or PET/CT does have a higher global accuracy in assessing the response for NAC in breast cancer. Comparing with clinical response, metabolic response plays a potential role in directing therapy for breast cancer. Factors which affected the accuracy of FDG-PET assessment included PET timing point, SUV reduction rate as threshold value and ER expression.

Breast Cancer; Fluorodeoxyglucose; Position Emission Tomography; Neoadjuvant Chemotherapy; Meta-Analysis

Y. Xi, M. Zhang, R. Guo, M. Zhang, J. Hu and B. Li, "Meta-Analysis: ¹⁸F-FDG PET or PET/CT for the Evaluation of Neoadjuvant Chemotherapy in Locally Advanced Breast Cancer," Journal of Cancer Therapy, Vol. 3 No. 5A, 2012, pp. 662-672. doi: 10.4236/jct.2012.325086.