18F-FES PET-CT Scan in Patients of Histopathologically Proven Estrogen Receptor Positive Breast Carcinoma at a Tertiary Care Facility

Aims: To ascertain successful labeling and image performance of 18F-FES PET-CT scan in patients who have histopathologically diagnosed estrogen positive breast cancer. Study Design: Histopathologically proven estrogen receptor positive patients were enrolled for 18F-FES PET-CT scan. Place and Duration of Study: Department of Nuclear Medicine, Department of Radiopharmacy and Department of Oncology, Institute of Nuclear Medicine and Oncology Lahore- INMOL. Duration of the study including planning phase and performance of imaging was 6 weeks spanning between July till Aug 2021. Methodology: 18F-FES was produced by direct nucleophilic radio-fluorination of 3-O-methoxymethyl-16,17 O sulfuryl-16-epiestriol followed by acidic hydrolysis at INMOL. After quality control tests, 18F-FES was injected to the patients. At 60 minutes post injection, each patient underwent PET-CT imaging in supine position as per standard protocol given in the published literature. Image interpretation and processing was performed. Results: Study was performed on 2 patients. The first patient had estrogen receptor positive breast tumour on trucut biopsy and the second patient presented after excision biopsy. The second patient demonstrated skeletal, nodal and pulmonary metastases.18F-FES uptake was observed in the primary tumour as well as in all metastatic sites. Conclusion: 18F-FES can successfully be labeled and 18-FES PET-CT can be performed in estrogen receptor positive breast cancer patients to take appropriate treatment decisions.