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

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

Applications of Dual Energy CT for Improving Staging and Monitoring of Therapy Response 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.

This is a single-arm study. Each patient will receive an unenhanced dual energy CT scan followed by a contrast-enhanced scan as part of clinical routine work up. No change in the contrast material injection protocol will be performed for this this study.

The subject's diagnostic scan will be preceded by a not clinically indicated non enhanced dual energy scan. The overall radiation dose to the patient for the first and second acquisition will be twice the radiation dose of a conventional CT of the chest, abdomen and pelvis. The non enhanced dual energy scan will be repeated during a clinical follow-up after the subject's first three months of enrollment and at a clinical follow-up after six months of enrollment. The clinically-indicated, contrast-enhanced diagnostic scan will be performed according to standard of care.

Optimal Threshold for Iodine Uptake to Differentiate Between Therapy Response and Progression of Metastatic Bone Disease

Sensitivity of Optimal Threshold for Iodine Uptake to Differentiate Between Therapy Response and Progression of Metastatic Bone Disease

Specificity of Optimal Threshold for Iodine Uptake to Differentiate Between Therapy Response and Progression of Metastatic Bone Disease

Accuracy of Optimal Threshold for Iodine Uptake to Differentiate Between Therapy Response and Progression of Metastatic Bone Disease

Reader Performance for Iodine Maps and Fused Images to Differentiate Between Therapy Response and Progression of Metastatic Bone Disease

To analyze the feasibility to detect bone metastasis at baseline more accurately, unenhanced bone marrow imaging will be calculated and additional dual energy based, calcium corrected iodine maps will be used to determine a threshold for detection of vital bone metastasis in order to calculate color coded bone maps for risk of presence of bone metastases.

Inclusion Criteria: Oncology patients with castrate-resistant prostate cancer planned for therapy with abiraterone acetate or enzalutamide and prednisolone undergoing clinically indicated MDCT (multi-detector computed tomography) of the chest, abdomen and pelvis > 18 years old Serum creatinine < 2.0 BMI < 35kg/m^2 Sign informed consent Exclusion Criteria: - History of anaphylactoid reaction to iodinated contrast material