Identification of Key Anatomic Structures on Magnetic Resonance Imaging During Prostate Stereotactic Body Radiation...

Area of Science:

• Urology
• Radiation Oncology
• Medical Imaging

Background:

• Erectile dysfunction is a common post-treatment complication for prostate cancer (PCa) patients.
• Radiation therapy can damage critical neurovascular bundles (NVBs) and arteries near the prostate.
• Understanding the precise anatomy of these structures is crucial for minimizing radiation-related damage.

Purpose of the Study:

• To evaluate the anatomical patterns of NVBs, internal pudendal arteries (IPAs), and penile structures.
• To assess the relationship between these structures and the prostate using magnetic resonance imaging (MRI).
• To provide illustrative MRI examples for radiation oncologists to aid in treatment planning.

Main Methods:

• Retrospective analysis of MRI scans from 160 prostate cancer patients undergoing MRI-guided radiation therapy.
• Classification of NVB patterns (classical, adherent, absent).
• Measurement of the distance between the IPA and prostate capsule, and membranous urethral length.

Main Results:

• The 'classic' NVB pattern was most common (80.0%-85.0%), followed by 'adherent' (13.8%-18.1%).
• Median distance from IPA to prostate capsule was 2.3 cm; median membranous urethral length was 1.5 cm.
• No significant association found between anatomical features, prostate volume, or lesion characteristics.

Conclusions:

• Most prostate cancer patients exhibit anatomy conducive to sparing critical erectile function structures during radiation.
• MRI provides valuable anatomical detail for radiation oncologists to optimize treatment planning and dose reduction.
• Illustrative MRI examples can enhance the recognition and contouring of sensitive structures, potentially improving outcomes.