Investigation of Changes in Bone Scan Imaging Before and After Intravenous Bisphosphonate Therapy for Osseous Metastases From Breast Cancer

Inclusion Criteria:

* Patients receiving intravenous biphosphonate therapy (zoledronic acid 4 mg or renal dose equivalent) as part of their treatment regimen, who are diagnosed with metastatic breast cancer involving surrounding bone.
* Patients must have had prior treatment zoledronic acid (4 mg or adjusted dose for renal function) within 8 weeks.
* The patients clinical status as assessed by a treating physician must be deemed appropriate for continuing treatment with zoledronic acid
* The patient's clinical status, as assessed by a treating physician, must be deemed appropriate for an evaluation with a bone scan
* The patient's medical status as assessed by a treating physician must be medically appropriate to receive zoledronic acid within the study time frame and in association with the study bone scan

Exclusion Criteria:

* No evidence of bone metastases, or less than 3 osseous lesions felt to be consistent with bone metastases, on most recent bone scan performed for clinical indications prior to study entry.
* Patients with illnesses, or conditions that would prevent them from understanding the nature of the study and complying with the protocol requirements