FDG PET/CT in Breast Cancer Bone Mets

This study will evaluate baseline uptake on a FDG PET/CT scan in patients with breast cancer that has spread to the bones. A repeat FDG PET/CT scan will be done 4 weeks after the start of new breast cancer hormone treatment and again at 12 weeks after treatment start. The baseline uptake and change in uptake after the repeat scans will be compared to clinical long term outcomes such as time to progression and overall survival. In addition the uptake will be compared to the incidence of skeletal related events that are common occurrences in patients with cancer that has spread to the bones.

Inclusion Criteria: 1. Adult patients, at least 18 years of age, with a history of pathologically confirmed ER+ breast cancer 2. Biopsy proven or clinically obvious documented bone metastases from breast cancer (with the majority of the disease burden in the bone) 3. Patients planning to start new endocrine targeted therapy (any line of therapy is acceptable and any endocrine therapy is allowed) 4. Willing and able to comply with scheduled visits and serial imaging procedures 5. Agrees to allow access to clinical records regarding response to treatment and long term follow up. 6. Be informed of the investigational nature of this study and provide written informed consent in accordance with institutional and federal guidelines Exclusion Criteria: 1. Women who are pregnant or breast feeding 2. Uncontrolled diabetes mellitus (fasting glucose greater than 200 mg/dL) 3. Inability to tolerate imaging procedures (e.g. claustrophobia, severe pain) 4. Weight exceeding capacity of imaging table 5. Previous treatment with radiation or surgery to a significant percentage of bony metastatic sites 6. Treatment with marrow stimulating agents (e.g. granulocyte colony stimulating factor (GCSF)) within 3 weeks of baseline scan