Related Experiment Video
Updated: Aug 21, 2026
A Cognitive Fusion-guided Prostate Biopsy Using Multiparametric Magnetic Resonance Imaging and Transrectal Ultrasound
Published on: March 21, 2025
Deep learning-enhanced image registration for accelerating daily adaptive magnetic resonance imaging-guided prostate
Cornel Zachiu1, Gijsbert H Bol1, Alexis N T J Kotte1
1Department of Radiotherapy, UMC Utrecht, Heidelberglaan 100, 3508 GA, The Netherlands.
Background And Purpose:
Daily auto-contouring remains a workflow bottleneck in magnetic resonance-guided adaptive prostate radiotherapy (MRgRT). This study proposes and clinically validates a novel deep learning-enhanced deformable image registration (DIR) solution to accelerate this critical step.
Materials And Methods:
A hybrid framework combining a 3D nnU-Net segmenting bladder/rectum on planning/daily MRI with an in-house DIR algorithm was implemented for 5-fraction prostate MRgRT ( Gy) on an MR-Linac. The DIR uses nnU-Net contours to propagate target and organs-of-interest structures. The solution was clinically deployed and evaluated in 275 patients/1375 fractions.
Results:
Evaluation following clinical introduction, has shown a median contouring time of 190 s, halving the time required by the previously-employed vendor-provided solution. Quantitative evaluation showed high agreement with clinically approved contours: Dice similarity coefficients 0.9 and 95th percentile Hausdorff distances 2.0 mm for most structures.
Conclusions:
The implemented solution demonstrated reliable, high-accuracy daily auto-contouring, significantly accelerating MRgRT workflows. It has become our institutional standard for prostate treatments. Future work will extend this approach to additional treatment sites and modalities.
