Inclusion Criteria:

1. Patients must have histologically confirmed prostate cancer that has become
castration resistant.

2. Radiological or pathological evidence of bone metastases. (Positive bone scan, MRI,
or CT or pathological fracture, or pathological sample from bone biopsy showing
evidence of metastatic prostate cancer).

3. Patient has not yet started on BP therapy for metastatic castration resistant
prostate cancer.

4. Renal and hepatic function within the institutional normal range.

5. Age >/= 18 years

6. ECOG performance status < 2

7. Life expectancy > 6 months

8. Ability to understand and the willingness to sign a written informed consent
document.