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Updated: May 5, 2026
A Cognitive Fusion-guided Prostate Biopsy Using Multiparametric Magnetic Resonance Imaging and Transrectal Ultrasound
Published on: March 21, 2025
Multi-parametric MRI-guided focal tumor boost using HDR prostate brachytherapy: a feasibility study
Josh Mason1, Bashar Al-Qaisieh2, Peter Bownes2
1Medical Physics, St James's Institute of Oncology, Leeds Teaching Hospitals NHS Trust; Division of Medical Physics, University of Leeds.
Purpose:
This study investigates the feasibility of delivering focal boost dose to tumor regions, identified with multi-parametric MRI, in high-dose-rate prostate brachytherapy.
Methods And Materials:
T2-weighted, diffusion-weighted, and dynamic-contrast-enhanced MRI were acquired the day before treatment and analyzed retrospectively for 15 patients. Twelve patients had hormone therapy before the MRI scan. The tumor was delineated on MRI by a radiologist and registered to treatment planning transrectal ultrasound images. A margin based on analysis of delineation and registration uncertainties was applied to create a focal boost planning target volume (F-PTV). Delivered treatment plans were compared with focal boost plans optimized to increase F-PTV dose as much as allowed by urethral and rectal dose constraints.
Results:
Tumors were delineated in all patients with volumes 0.4-23.0cc. The margin for tumor delineation and image registration uncertainties was estimated to be 4.5 mm. For F-PTV, the focal boost treatment plans increased median D90 from 17.6 to 20.9 Gy and median V150 from 27.3% to 75.9%.
Conclusions:
MRI-guided high-dose-rate prostate brachytherapy focal tumor boost is feasible-tumor regions can be identified even after hormone therapy, and focal boost dose can be delivered without violating urethral and rectal dose constraints.
