Imaging Staging and Response Prediction in Metastatic Hormono-Sensitive Prostate Cancer Patients Receiving Enzalutamide

Inclusion Criteria:

* Male aged 18 years or older;
* Histologically confirmed adenocarcinoma of the prostate without neuroendocrine differentiation or small cell features;
* Three consecutive rises of PSA, 1 week apart, resulting in two 50% increases over the nadir, with PSA of at least \> 2 ng/mL but preferably \>20 ng/mL;
* Progressive disease defined by rising PSA levels plus by evidence of progressive and measurable soft tissue or bone disease by 11C or 18F-Choline PET/CT, Whole Body MRI or both;
* No prior treatment with cytotoxic chemotherapy;
* Eastern Cooperative Oncology Group (ECOG) score 0-2;
* A life expectancy of at least 12 months;
* Written informed consent;

Exclusion Criteria:

* Treatment with androgen deprivation therapy with a gonadotropin-releasing hormone analogue, luteinizing hormone-releasing hormone antagonist, or bilateral orchiectomy within 6 months of enrolment (Day1 visit);
* Treatment with anti-androgens such as bicalutamide, nilutamide or flutamide within 6 weeks of enrolment (Day 1 visit);
* Treatment with 5-α reductase inhibitors (finasteride, dutasteride), estrogens, cyproterone acetate within 4 weeks of enrolment (Day 1 visit);
* Severe concurrent disease, infection, or co-morbidity that, in the judgment of the Investigator, would make the patient inappropriate for enrolment;
* Known or suspected brain metastasis or active leptomeningeal disease;
* History of another malignancy within the previous 5 years other than curatively treated non melanomatous skin cancer;
* Total bilirubin, alanine aminotransferase (ALT) or aspartate aminotransferase (AST) 2.5 times the upper limit of normal at the Screening visit;
* Creatinine \> 177 µmol/L (2 mg/dL) at the Screening visit;
* Hemoglobin \<6 mmol/L, White blood cells \< 4.0 x 10\^9/L, Platelets \< 100 x 10\^9/L;
* History of seizure or any condition that may predispose to seizure. Also, history of loss of consciousness or transient ischemic attack within 12 months of enrolment (Day 1 visit);
* Contra-indication for MRI (e.g. pacemaker).