The Contribution of 18 F-FES PET/CT in Therapy Management of Estrogen Receptor Positive Breast Cancer

Oflas M., Has Şimşek D., Işık E. G., Cabıoğlu N., İbiş K., Aydıner A., ...More

35'th Annual Congress of Nuclear Medicine, Barcelona, Spain, 15 - 19 October 2022

  • Publication Type: Conference Paper / Summary Text
  • City: Barcelona
  • Country: Spain
  • Istanbul University Affiliated: Yes


The Contribution of 18 F-FES PET/CT in Therapy Management of Estrogen Receptor Positive Breast


Purpose: We investigated the contribution of 18 F-FES PET/CT in therapy management of estrogen

receptor positive (ER+) breast cancer.

Methods: Pre-treatment prospective 18 F-FES PET/CT scans were planned to the patients who

performed 18 F-FDG PET/CT for ER+ breast cancer (ER: >10%). The histopathology, MRI-US, PET/CT

findings and follow-up data of the patients were documented. PET/CT findings were interpreted with

the knowledge of clinical and histopathological findings. Suspicious lesions were verified by further

imaging or biopsy. The contribution of 18 F-FES PET/CT on therapy management was evaluated

through pre and post 18 F-FES PET/CT questionnaire forms filled by clinicians. Management changes

were categorized as inter or intramodality change based on 18 F-FES PET/CT findings.

Results: 14 female patients who underwent 18 F-FDG and 18 F-FES PET/CT for staging (n: 12) or

restaging (n: 2) of ER+ breast cancer were included to study (mean age: 54). Based on breast

MRI-US and 18 F-FDG PET/CT findings, early stage, locally advanced and metastatic disease were

determined in 3(21,4 %), 6(35,7 %), and 5(35,7 %) patients, respectively. In 2 of them, multiple

metastases (n:>20) were detected by both PET/CT modalities. In the remaining 12 patients, 18 F -FDG

PET/CT defined 35 FDG positive metastases, while 18 F-FES PET/CT defined 33 ER+ metastases. The

median SUVmax of primary tumor in 18 F-FDG and 18 F-FES PET/CT was 4,65 (1,5 - 10,9) and 2,76 (0,98-

8,63); of axillary lymph node metastases 3,36 (2,7 - 15,7) and 2,69 (1,2 - 13,88); of non-axillary

metastases 3,31 (1,72-13,56) and 5,01 (0,93-14,68), respectively. 18 F-FES PET/CT findings downstaged

4 patients (28.5%), and therapy management was changed in 5 patients (35, 7%). Intermodality

change was occurred in 4 patients; 2 of them were operated initially and 2 patients were operated

after neoadjuvant chemotherapy instead of receiving adjuvant chemotherapy. Intramodality change

was occurred in one patient; radiotherapy area increased after 18 F-FES PET/CT.

Conclusion: 18 F-FES PET/CT contributed the therapy management of ER (+) breast cancer by

increasing accuracy combining with 18 F-FDG PET/CT in selected cases.

Key words: 18 F-FES PET/CT , 18 F -FDG PET/CT, Estrogen receptor, breast cancer