FES PET
ER+ FES PET/CT
FES PET reveals ER+ disease beyond FDG
Discovery
The initial FDG PET/CT demonstrated only moderate tracer uptake within a 5-cm left breast mass and did not reveal metastatic disease. In contrast, the FES PET/CT not only confirmed the primary tumor but also demonstrated multiple intra-breast satellite lesions, left axillary nodal metastases, and innumerable bone metastases with variable ER-targeted tracer avidity - disease not apparent on the prior FDG study.
Exams
The patient has biopsy-proven ER+ left breast carcinoma and known left axillary nodal metastasis. The patient first underwent an FDG PET/CT (bottom panel) at an outside institution for initial staging. Northern California PET Imaging subsequently performed an F-18 fluoroestradiol (FES; Cerianna™) PET/CT (upper panel) for comparison.
Understanding the Radiotracer
Fluoroestradiol F-18 - known clinically as FES or Cerianna - is an estrogen-receptor-targeted PET radiopharmaceutical. FES PET/CT visualizes ER expression throughout the body and can reveal ER+ disease that FDG alone may underestimate or miss.
When to Use FES vs. FDG (or Both)
- FDG PET/CT appears limited or equivocal for ER+ disease detection
- Extent of ER-positive disease will influence systemic therapy decisions
- Staging or restaging requires confirmation of ER expression in suspected metastases
- Bone-predominant disease is suspected, where FDG may be less sensitive
FDG PET/CT remains preferred when
Tumors show high glycolytic activity (high-grade, ER-, triple-negative, or inflammatory phenotypes). Evaluating overall metabolic activity, tumor aggressiveness, or treatment response.
When to perform both
Initial staging and therapy planning in ER-positive metastatic disease, leveraging complementary FDG (metabolism) and FES (ER expression), including assessment of ER heterogeneity and progression not explained by FDG alone.
Locations
Sacramento
Rocklin