Endorectal digital prostate tomosynthesis (endoDPT): a proof-of-concept study

Area of Science:

• Medical Imaging
• Radiology
• Biomedical Engineering

Background:

• Current imaging methods struggle to visualize fine details of small structures within the prostate.
• Low dose rate brachytherapy (LDRBT) seed visualization is crucial for accurate dosimetry.
• There is a need for advanced imaging techniques to improve prostate cancer treatment planning and monitoring.

Purpose of the Study:

• To introduce and characterize endorectal digital prostate tomosynthesis (endoDPT), a novel high-resolution prostate imaging method.
• To evaluate the resolution capabilities of endoDPT for visualizing fine structures, specifically LDRBT seeds.
• To compare the performance of endoDPT with computed tomography (CT) for prostate imaging.

Main Methods:

• Developed endoDPT using an endorectal x-ray sensor and an external x-ray source.
• Characterized endoDPT resolution using modulation transfer function (MTF) and artifact spread function (ASF) in phantoms.
• Assessed qualitative resolution by imaging LDRBT seeds in ex vivo canine prostates and comparing with CT.

Main Results:

• EndoDPT demonstrated high in-plane spatial resolution, with sensor MTF reaching 10% at 11.50 mm⁻¹.
• Fine structures of LDRBT seeds, including the 0.05 mm shell, were visible with endoDPT but not CT.
• While endoDPT exhibited an overshoot artifact due to partial angular sampling, it significantly outperformed CT in visualizing fine details.

Conclusions:

• Endorectal digital prostate tomosynthesis (endoDPT) achieves high in-plane spatial resolution, surpassing current CT capabilities for fine structure visualization.
• The ability to visualize LDRBT seeds with greater detail holds promise for improving patient-specific dosimetry.
• EndoDPT is a promising technology for prostate imaging, warranting further optimization and clinical utility studies.