Applications of Dual Energy CT in Patients With Osseous Metastases From Castrate-resistant Prostate Cancer

The purpose of this study is to establish a more accurate and precise way to image (take
pictures of) metastatic bone disease in patients with prostate cancer for staging and
monitoring response to therapy. More specifically, the study aims to evaluate the
capabilities of dual energy CT as a more precise and accurate tool for staging and monitoring
of therapy response in patients with osseous metastases from castrate-resistant prostate
cancer.

Bone metastases in prostate cancer patients are a clinical and diagnostic challenge to image.
Sometimes very small metastatic bone lesions may only become detectable by imaging in
response to therapy due to increased bone deposition during the first three months after
therapy. Commonly used imaging tests (such as regular CT or bone scan) are unable to reliably
tell the difference between increased bone deposition (therapy response) and growth of the
lesion (progressive disease). This diagnostic challenge may have profound negative effects on
patient management since it may require additional imaging before an accurate determination
of tumor response can be made. An appropriate determination of tumor response is needed for
appropriate management of prostate cancer. The investigators anticipate that the new imaging
tested in this study (called dual energy CT) may provide additional critical information in
this clinical and diagnostic challenge.

Approximately 100 people with prostate cancer and metastatic bone disease will take part in
this study. At enrollment, three months, and six months, they will will receive a
non-enhanced (without contrast) dual energy CT scan of the chest, abdomen and pelvis before
receiving their routine, clinical contrast-enhanced CT scan.