The primary aim of the study is to assess the elasticity (Young's modulus) of cancerous tumor foci, of normal peripheral zone, and of normal transition zone in the prostate. Images obtained with the Supersonic Imagine Aixplorer scanner prior to radical prostatectomy are compared to whole-mount histology.

Inclusion Criteria:

• Patient over 18 years old, with prostate cancer and scheduled for radical prostatectomy

Exclusion Criteria:

• Medical history of prostate surgery or radiotherapy of prostate
• Medical history of abdominal perinéanal amputation or whole of state which prevent to use endorectal probe