Pilot Study Evaluating a Rat Model of Radiation-induced Erectile Dysfunction Using an Image-guided Microirradiator

Area of Science:

• Radiation oncology
• Urology
• Animal models

Background:

• Prostate cancer radiotherapy can cause radiation-induced erectile dysfunction (RIED).
• Developing accurate animal models is crucial for studying RIED mechanisms and testing therapies.

Purpose of the Study:

• To establish a feasible and reproducible rat model of RIED following targeted prostate irradiation.
• To utilize an image-guided irradiation unit designed for small-animal research.

Main Methods:

• Used the X-RAD 225Cx research platform for targeted prostate irradiation in rats.
• Administered radiation doses of 15, 20, or 25 Gy to the prostate.
• Assessed erectile function via intracavernous pressure (ICP) measurements and cyclic guanosine monophosphate (cGMP) levels at 9 weeks post-irradiation.

Main Results:

• Confirmed accuracy of the image-guided irradiation technique.
• Observed dose-dependent decreases in ICP in irradiated rats without significant toxicity.
• Found significantly decreased cGMP levels in the penile cavernosa of rats receiving 25 Gy compared to controls.

Conclusions:

• The micro-image-guided radiation therapy (micro-IGRT) platform enables the development of a reproducible RIED rat model.
• This model is suitable for prostate cancer research and the study of RIED.