FDG-PET/CT and MRI for Evaluation of Pathologic Response to Neoadjuvant Chemotherapy in Patients With Breast Cancer: A Meta-Analysis of Diagnostic Accuracy Studies

Abstract

Introduction. This study compared the diagnostic test accuracy of magnetic resonance imaging (MRI) with that of 18 F-fluoro-2-glucose-positron emission tomography/ computed tomography (FDG-PET/CT) imaging in assessment of response to neoadjuvant chemotherapy (NAC) in breast cancer. Methods. A systematic search was performed in PubMed and EMBASE (last updated in June 2015). Studies investigating the performance of MRI and FDG-PET or FDG-PET/CT imaging during or after completion of NAC in patients with histologically proven breast cancer were eligible for inclusion. We considered only studies reporting a direct comparison between these imaging modalities to establish precise summary estimates in the same setting of patients. Pathologic response was considered as the reference standard. Two authors independently screened and selected studies that met the inclusion criteria and extracted the data.

Dedicated Breast Positron Emission Tomography for the Evaluation of Early Response to Neoadjuvant Chemotherapy in Breast Cancer

“…In a metaanalysis, Wang et al found that the accuracy of PET was greater when performed early (after 1-2 cycles of chemotherapy) rather than late. Another recent meta-analysis 10 of studies comparing FDG-PET to DCE-MRI showed that PET outperformed MRI in assessing early treatment response, with similar sensitivity, but higher specificity.…”

The Value of F-18-fluorodeoxyglucose Positron Emission Tomography/Computed Tomography for the Detection of Residual Breast Tumor or Axillary Metastasis after Neoadjuvant Chemotherapy in Invasive Ductal Carcinoma of the Breast

“…On the other hand, MRI had better performance when either of the two methods was used after the completion of neoadjuvant treatment, with significantly higher sensitivity (88% vs 57%) (19). There is a wide range of sensitivity and specificity across studies, which may be attributed to the heterogeneity between studies (17).…”

“…On the other hand, FDG-PET has been shown to have low sensitivity for small lesions (13). To date, several studies examined the role of PET/CT in predicting response to neoadjuvant chemotherapy when performed after the completion of neoadjuvant chemotherapy and before surgery, with inconsistent findings, most of them comparing the findings with that of MRI (6,(14)(15)(16)(17)(18)(19).…”

Now Is the Time to Use 18F-FDG PET/CT to Optimize Neoadjuvant Treatment in Triple-Negative Breast Cancer!

“…One showed that PET was more sensitive and MRI more specific to predict pCR (7). The second showed that PET performed during NAC outperformed MRI with higher specificity (0.69 vs. 0.42) and fairly similar pooled sensitivity (0.91 vs. 0.89) (8). Despite the relatively high sensitivity, interim PET/CT in breast cancer has not yet gained a wide audience, as opposed to other similar settings in diseases such as Hodgkin disease and aggressive non-Hodgkin lymphomas (9).…”

“…Four metaanalyses have been published in the last few years, showing a sensitivity for 18 F-FDG PET imaging close to 80%-85% and a little less specificity (3)(4)(5)(6). Two other metaanalyses compared PET with MRI (7,8). One showed that PET was more sensitive and MRI more specific to predict pCR (7).…”