Can 18F-Fluoroestradiol positron emission tomography become a new imaging standard in the estrogen receptor-positive breast cancer patient: A prospective comparative study with 18F-Fluorodeoxyglucose positron emission tomography?

Abstract

Correct staging is the most crucial for the treatment outcome in cancer management. Molecular imaging with 18F-fluoroestradiol (FES) positron emission tomography-computed tomography (PET-CT) targets estrogen receptor (ER) and may have a higher incremental value in diagnosis by aiding specificity. We enrolled 12 female breast cancer patients prospectively and did 18F-FES PET-CT and 18F-fluorodeoxyglucose (FDG) PET-CT within 1 week interval time. Lesion detection sensitivity was compared for a total number of lesions and for nonhepatic lesions only by McNemar test. 18F-FES PET-CT was taken as reference in case of indeterminate lesions. The incremental value reported by identifying 18F-FES exclusive lesions and by characterization of 18F-FDG indeterminate lesions. Spearman rank test was used to correlate ER expression and maximum standardized uptake value (SUVmax). Two ER-negative patients with no 18F-FES uptake were excluded. Ten ER-positive patients with 154 disease lesions were finally analyzed. 18F-FDG picked-up 142 lesions (sensitivity 92.21%), whereas 18F-FES picked-up 116 lesions (sensitivity 75.32%) and this difference was statistically significant. For nonhepatic lesions (n = 136) detectability, 18F-FDG picked-up 124 (sensitivity 91.18%), whereas 18F-FES picked-up 116 (sensitivity 85.29%) lesions and this difference was not statistically significant. Beside 12 exclusive lesions, 18F-FES characterized 41 (27.5%) 18F-FDG indeterminate lesions. Overall 18F-FES impacted 20% patient management. The positive trend was also seen with 18F-FES SUVmax with ER expression and negative with 18F-FDG SUVmax. We conclude, 18F-FDG has overall better sensitivity than 18F-FES PET-CT, however for nonhepatic metastasis difference was not significant. 18F-FES PET-CT better-characterized lesions and impacted 20% patient management. Therefore, 18F-FES PET-CT should be used with 18F-FDG PET-CT in strongly ER expressing patients for better specificity.

Whole-Body Characterization of Estrogen Receptor Status in Metastatic Breast Cancer with 16α-18F-Fluoro-17β-Estradiol Positron Emission Tomography: Meta-Analysis and Recommendations for Integration into Clinical Applications

“…Five studies included lesion‐level results for nonbreast metastatic lesions. In the four smaller studies , all 26 ER‐positive lesions by IHC were also ER positive by 18 F‐FES PET, and all 6 ER‐negative lesions were ER negative by 18 F‐FES PET. (Sensitivity and specificity estimates below 100% are due to continuity corrections to stabilize calculations.)…”

18F-FES PET/CT Influences the Staging and Management of Patients with Newly Diagnosed Estrogen Receptor-Positive Breast Cancer: A Retrospective Comparative Study with 18F-FDG PET/CT

“…Therefore, we defined this MLN lesion as false positive of 18 F‐FDG (2.9%). We will discuss these remaining 238 lesions in the following sections .…”

“…18 F‐FES was slightly higher in the sensitivity of lesion diagnosis (90.8% to 91.9%). In the study by Gupta et al, different results were observed in 10 treatment‐naive patients with ER‐positive breast cancer, where higher sensitivities in 18 F‐FDG PET compared with 18 F‐FES PET were reported (92.21% vs. 75.32%, respectively) . Notably, some lesions of ER‐positive characteristics were converted to ER‐negative phenotypes after treatment, and the heterogeneity of 18 F‐FES uptake was higher in patients with recurrent or metastatic breast cancer than untreated patients .…”

Breast Cancer: Evaluating Tumor Estrogen Receptor Status with Molecular Imaging to Increase Response to Therapy and Improve Patient Outcomes

“…While 18 F-FES imaging has many benefits, it does have some limitations related to its ability to detect liver metastases because of the increased uptake of 18 From a sensitivity and specificity perspective, 18 F-FES has a high accuracy for the detection of ER+ lesions; which was illustrated in a meta-analysis conducted on 12 different studies that evaluated patients who had 18 F-FES imaging and compared FES results to biopsy/histopathology staining (Allred) results in patients with breast cancer (30-32, [37][38][39][40][41][42][43][44][45]. The meta-analysis demonstrated that for metastatic lesions, a test sensitivity of 100% and a specificity of 99% (30-32, [37][38][39][40][41][42][43][44][45]. When combined (primary lesion + metastatic lesions), FES imaging resulted in a sensitivity of 81% and a specificity of 80% when compared to biopsy/histopathology results (30-32, 37-45).…”