Union pour le Développement de la Radiologie Interventionnelle (UDRI)

Non-profit association (law 1901) Paris France

Founded in 2003 by Drs Didier Bonnel and François Cornud, the UDRI aims to promote diagnostic and interventional prostate MRI.

Prostate MRI is now recommended before biopsy to localize focal suspicious areas requiring a targeted biopsy. Expertise is required to assign the right PI-RADS score to a focal lesion detected on MRI.

The interventional program includes MRI-directed prostate biopsies and focal treatment of  prostate cancer.


Continuing education


The association organizes a teaching program (workshops and teaching courses) per year on prostate MRI, validated by a French or European accreditation.


Clinical research


The association plans to develop interventional prostate MRI to guide prostate biopsies and focal treatment of prostate cancer with a low risk of progression.

Cryo- or interstitial laser  therapy can be used for treatment. Monitoring of cryoablation is done under real-time TRUS guidance with a high frequency (29MHz) transducer (micro-ultrasound, Exact Imaging, Canada). Laser focal ablation is done under MRI guidance and the procedure is assisted by an MRI compatible robot (Figures 1 and 2)  to shorten the procedure time and increase its accuracy.
Focal treatment spares the healthy tissue adjacent to the tumor, protecting the patient from side effects (sexual impotence, urinary incontinence) that can be observed after radical treatment (surgery or radiation).

The association is participating in a multicenter study to demonstrate the safety and efficacy of MRI-guided focal laser ablation of prostate cancer.

Fig 1: Photograph shows the pneumatic robot, installed between the patient’s legs during the biopsy. The motors are activated by compressed air distributed by plastic tubes, visible at the back of the robot. The needle guide is attached at the front of the device (arrow).
Fig 2: Robotic assisted transrectal biopsy and focal therapy. The tumor (arrow, A) is anteriorly located. The robot (B) steered the needle guide towards the tumor (Gleason 3+4) During FLA , the thermal mapping (arrow, C) monitors in real time the local temperature. At the end of the FLA, Dynamic Contrast Enhanced MRI show the ablated devascularized area (arrow, D).