This study will determine the delayed neurotoxicity (12 months) of a hypofractionated high dose irradiation (3 Gy x 9) associated with zoledronic acid.

The administration of zoledronic acid repeat dosages defined under the Authorisation on the Market.

All patients receive a total dose of 27 Gy divided into 3 fractions of 9 Gy performed at least 48 hours apart each, for a treatment to J1, J3 and J5.

Inclusion Criteria:

Adenocarcinoma of the prostate metastatic Age> 18 years3.

• Life expectancy> 12 months;
• Performance Index status <3 PSA ≥ 4 ng / ml Zoledronic acid treatment in progress as recommended by the Authority for the Marketing Creatinine clearance above 30 ml / min Lack of maintenance causing disabling pain not lying down long (30 minutes) No history of radiotherapy to the region to be irradiated Absence of neurological signs compression Distance between the metastasis and spinal cord ≥ 5 mm Absence of metastases unstable metastatic epidural spinal cord compression or may require surgery before radiotherapy

Exclusion Criteria:

• Concomitant treatment with a drug testing, participation in another clinical trial within <30 days
• Presence of central system nervous desease (symptoms or progressive), Patient with a severe neurological disease, current manifestations of peripheral neuropathy> grade 2 NCI-CTC V4 Existence of another severe pulmonary disease, liver or kidney, digestive likely to be exacerbated by treatment,
• Untreated with zoledronic acid
• Treatment with a bisphosphonate other than Zoledronic acid
• Clinically significant hypersensitivity to zoledronic acid, other bisphosphonates or to any excipients in the formulation of Zometa.
• Creatinine clearance below 30 ml / min
• History of another primary cancer (except basal cell skin cancer)
• Or demented patient with altered mental status who can not obtain informed consent. / Persons deprived of liberty or under guardianship
• Pain not resulting in maintaining the prolonged supine position (30 minutes)
• PSA below 4 ng / ml
• History of radiotherapy in localized tumor site
• Distance between the metastasis and spinal cord <5 mm
• Monitoring impossible because of psychological, sociological or because of geographical distance.