Study of Prostate Perfusion Before Embolization in Patients With Symptomatic Prostate Adenoma

Over the last 5 years, prostate embolization has developed as a treatment for symptomatic prostate adenoma. This long, complex procedure is effective in 80% of cases. Currently there are no means of better selecting patients to avoid this long procedure in non-responders. The hypothesis is that prostate perfusion parameters are correlated with the efficacy of embolization. Studying these prostate perfusion parameters in perfusion CT and evaluating prostate Iodine load in dual energy computed tomography will make it easier to select those patients who are most likely to respond.

The hypothesis is that there are two types of prostate vascularization in patients with symptomatic prostate adenoma:

* prostates mainly vascularized by large caliber prostate arteries with high flow, for which perfusion parameters in favor of hyper-perfusion will be found. In this case, prostate artery embolization will be effective;
* prostates vascularized by a network of collaterals, with low flow-rates, for which perfusion parameters in favor of hypo-perfusion will be found. In this case, prostate artery embolization will not be very effective.

The purpose of this study is to investigate the association between prostate perfusion parameters (peak time, transit time, blood volume, capillary permeability) and the clinical efficacy of prostate embolization at 3 months. These perfusion parameters could become new biomarkers leading to better selection of patients eligible for efficient prostate embolization, in order to avoid a considerable treatment with no benefit for certain patients and thus limit their global exposure to X-rays during care.

Prior to this prospective study on patients with symptomatic benign prostate hypertrophy, a preliminary experimental study will be performed on a perfusion phantom in order to better understand the differences in the calculation of perfusion parameters according to the three main algorithms used. This will lead to optimization of the prostate perfusion protocol for the scanner: computed tomography acquisition parameters (kilovoltage, Milliamps per second) and therefore the X-ray dose delivered to patients, sampling frequency, and model to be used. The first results of this study have already led to modifications in scanner perfusion acquisition protocols for the initiation of clinical study.

Eligibility Criteria:
Inclusion Criteria:

* Patients with symptomatic benign prostatic hypertrophy (prostate volume \> 50, IPSS \>7, QoL\>2) or patients catheterized after acute retention of urine with failed catheterization.
* Creatinine clearance \> 30 mL/min for one of the two Cockcroft-Gault/MDRD equations)
* Adult patients (≥18 years).
* Patients with an indication for prostate embolization.
* Patient with free and informed consent.
* Patient who have signed the consent form.
* Patient affiliated or beneficiary of a health insurance plan.

Exclusion Criteria:

* Hypersensitivity to the active substance or to one of the excipients of the iodized contrast medium.
* Severe renal impairment with renal function \<30mL/min.
* Contraindication to prostate embolization (aorto-iliac bypass)
* Patient participating in research defined as Category 1 Research Involving Human Subjects.
* Patient in an exclusion period as determined by another study.
* Patient under court protection, guardianship or curatorship.
* Patient unable to give consent.
* Patient for whom it is impossible to give informed information.