History
A 75-year-old female with recurrent, metastatic, invasive lobular breast cancer—8 years post-diagnosis and also in remission for lymphoma—underwent routine Fludeoxyglucose F 18 (18F FDG) Injection PET/CT imaging to evaluate disease progression. Two years prior, the patient had completed 5 years of letrozole therapy for the initial breast cancer diagnosis.
Routine 18F FDG PET/CT findings indicated diffuse 18F FDG-avidity throughout the osseous structures as well as sclerotic osseous lesions without 18F FDG-avidity above the remainder of marrow. A pelvic bone biopsy demonstrated metastatic breast cancer that was >99% estrogen receptor (ER) positive and 80% progesterone receptor (PR) positive. Subsequent treatment therapy included aromatase inhibitors (AIs), cyclin-dependent kinase (CDK4/6) inhibitors, and nuclear factor kappa-B ligand (RANKL) inhibitors.
The patient returned for a 1-year follow-up evaluation to help determine the extent of ER-positive osseous lesions. For the initial PET/CT, the patient was administered with 10.7 mCi (396 MBq) intravenous (IV) injection of 18F FDG, and approximately 1 hour later, a single-scan, whole-body acquisition was conducted on a Biograph mCT FlowTM system.
Two weeks later, the patient underwent a PET/CT using Cerianna™ (Fluoroestradiol F 18 [18F FES]) Injection, a PET imaging agent for use in recurrent or metastatic ER-positive breast cancer as an adjunct to biopsy (Cerianna NDA holder is Zionexa). The patient was administered with 5.5 mCi (202 MBq) IV injection of 18F FES, and approximately 80 minutes later, a single-scan, whole-body acquisition was conducted on a Biograph mCT Flow scanner.
Figure 1: Axial CT and 18F FDG PET/CT images show fluid density along the left breast prosthesis, as well as mild 18F FDG-avid left axillary and sub-pectoral nodes, indicating metastatic disease or a reaction secondary to implant rupture.
Findings
As seen in Figure 1, the initial 18F FDG images indicate fluid density along the left breast prosthesis secondary to implant rupture. The images show mild 18F FDG-avid left axillary and sub-pectoral nodes, which may be related to metastatic disease or a reaction due to the implant rupture. Stable diffuse activity throughout the axial skeleton and sclerotic osseous lesions without 18F FDG-avidity above the remainder of the marrow is also observed.
The 18F FES PET/CT images were acquired with a comparative protocol 2 weeks after the initial 18F FDG PET/CT and show increased heterogeneous activity throughout the axial and appendicular skeleton with focal areas of increased activity. The left axillary and sub-pectoral nodes are not indicative of 18F FES-avidity (Figure 2).
Upon review, the extent of ER-positive osseous metastases is better demonstrated with 18F FES PET compared to
18F FDG PET. 18F FES PET demonstrates increased heterogeneous activity throughout the osseous structures with focal areas of increased activity in comparison to the 18F FDG PET, which demonstrates increased diffuse activity in the marrow without focal 18F FDG-avid lesions (Figure 3).
Discussion
In this particular case, the utilization of 18F FES PET/CT helped confirm that the 18F FDG-avid left axillary and sub-pectoral lymph nodes were not due to ER-positive metastatic disease but possibly related to implant rupture. Additionally, the 18F FES PET better demonstrated metastatic osseous lesions with low 18F FDG-avidity.
Ultimately, the 18F FDG PET/CT helped confirm that there was no active metastatic process while the concurrent
18F FES PET/CT helped reinforce the extent of ER density in the metastatic lesions throughout the body in a patient under active treatment with AI and CDK4/6 inhibitors. Since disease progression was not observed on either the
18F FES PET/CT or the 18F FDG PET/CT, there was no change in the patient’s treatment management.
Conclusion
18F FES PET/CT—in conjunction with 18F FDG PET/CT—is a robust imaging radiotracer in the evaluation of ER-positive breast cancer when 18F FDG PET/CT is inconclusive. In addition, 18F FES PET is valuable in evaluating lesions with low 18F FDG-avidity, which is most commonly seen in patients with recurrent metastatic invasive lobular breast cancer.
Examination protocol
Scanner: Biograph mCT Flow
Imaging software: syngo®.via
The outcomes achieved by the Siemens Healthineers customers described herein were achieved in the customer’s unique setting. Since there is no
“typical” hospital and many variables exist (eg, hospital size, case mix, level of IT adoption) there can be no guarantee that others will achieve
the same results.
