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

Purpose We compared the clinical value of 16a-18F-fluoro-17b-estradiol (F-18-FES) positron emission tomography (PET)/computed tomography (CT) and F-18-fluoro-2-deoxy-D-glucose (F-18-FDG) PET/CT and investigated whether and how F-18-FES PET/CT affects the implemented management of newly diagnosed estrogen receptor positive breast cancer patients. Materials and Methods We retrospectively analyzed 19 female patients newly diagnosed with immunohistochemistry-confirmed estrogen receptor (ER)-positive breast cancer who underwent F-18-FES and F-18-FDG PET/CT within 1 week in our center. The sensitivity of F-18-FES and F-18-FDG in diagnosed lesions were compared. To investigate the definite clinical impact of F-18-FES on managing patients with newly diagnosed ER positive breast cancer, we designed two kinds of questionnaires. Referring physicians completed the first questionnaire based on the F-18-FDG report to propose the treatment regime, and the second was completed immediately after reviewing the imaging report of F-18-FES to indicate intended management changes. Results In total, 238 lesions were analyzed in 19 patients with newly diagnosed ER-positive breast cancer. Lesion detection was achieved in 216 sites with F-18-FES PET and in 197 sites with F-18-FDG PET/CT. These results corresponded to sensitivities of 90.8% for F-18-FES versus 82.8% for F-18-FDG PET/CT in diagnosed lesions. Thirty-five physicians were given the questionnaires referring to the treatment strategy, with 27 of them completing both questionnaires. The application of F-18-FES in addition to F-18-FDG PET/CT changed the management in 26.3% of the 19 patients with newly diagnosed ER-positive breast cancer. Conclusion Performing F-18-FES PET/CT in newly diagnosed ER-positive breast cancer patients increases the value of diagnosis equivocal lesions and treatment management compared with F-18-FDG PET/CT. Implications for Practice This study investigated whether 16a-18F-fluoro-17b-estradiol (F-18-FES) positron emission tomography (PET)/computed tomography (CT) affects the clinical management of patients with newly diagnosed estrogen receptor (ER)-positive breast cancer. Physicians completing two questionnaires comparing the clinical impact of 18F-FES and 18F-FDG on individual management plans in patients with newly diagnosed ER-positive breast cancer confirmed that 18F-FES scans led to change in management in 26.3% of the 19 patients with newly diagnosed ER positive breast cancer. This retrospective study indicates the potential impact of 18F-FES PET/CT on intended management of patients with newly diagnosed estrogen receptor positive breast cancer in comparison to 18F-fluoro-2-deoxy-D-glucose PET/CT.