1. Skin related problems around the planned venepuncture site (infection, phlebitis, scars)

2. Documented allergy to iodinated contrast or lidocaine.

3. Coagulopathy with an INR of greater than 1.5

4. Thrombocytopenia with platelets less than 25,000 uL

5. Renal insufficiency with a creatinine of 1.5 mg/dL

6. Documented current upper extremity or central venous thrombosis

7. DRE within 4 weeks prior to selective venous sampling

8. Prostate biopsy within 6 weeks prior to selective venous sampling.

9. Patient unable to sign his own consent or does not demonstrate full understanding of the procedure.

10. Patient has known metastatic disease or a known primary cancer other than prostate adenocarcinoma.

11. Patient has already been enrolled in this research study.

12. Life expectancy less than 6 months.

Peripheral vs. Selective Tumor Marker Venous Sampling in Prostate Cancer