The purpose of this study is to determine whether positron emission tomography / computed tomography (PET/CT) using fluorine-18 fluorocholine as an imaging agent can characterize regional responses to anti-androgen therapies in a manner that in the future aid in the customized planning of treatments for patients with androgen-insensitive prostate cancer.

Inclusion Criteria:

1. Provision of written informed consent.
2. Men, over 18 years of age, with histologically-confirmed diagnosis of prostate cancer
3. History of treatment by complete androgen blockade for greater than 3 months prior to enrollment
4. Serum testosterone level < 50 ng/ml. Castrate testosterone levels must be from orchiectomy or current therapy with leutinizing hormone-releasing hormone agonist.
5. Progressive disease evidenced by two consecutive rises in prostate specific antigen (PSA) above a nadir value, with the absolute value of the latest PSA > 2. 0 ng/ml.
6. Patient will be undergoing a therapeutic intervention under the supervision of his treating physician (urologist, oncologist).

Exclusion Criteria:

1. Other co-existing malignancies or malignancies diagnosed within the last 5 years with the exception of basal cell carcinoma or superficial transitional cell carcinoma of the bladder.
2. Serious underlying medical conditions that would otherwise impair the patient's ability to undergo imaging.
3. Patient weighs over 350 lbs (due to scanner weight limit).
4. Clinical life expectancy < 12 weeks.
5. Participated in other radioactive drug studies where estimated total cumulative dose within 1 year is > 0.05 Sievert for whole body, active blood-forming organs, eye lens, gonads, or 0.15 Sievert for other organs.
6. Concurrent Therapy. Allowed: prior hormonal therapy; concurrent leuteinizing hormone releasing hormone (LHRH) agonist; prior surgery; prior or concurrent bisphosphonate. Not allowed: concurrent anti-androgen or secondary hormonal therapy, prior or concurrent chemotherapy, concurrent radiotherapy or radioisotope therapy (e.g., strontium). Other: Prior radiotherapy or radioisotope therapy must be > 12 weeks since last treatment.