In prostate cancer radiotherapy, it is important to accurately identify and protect healthy organs near the prostate. One of these structures is the urethra, the tube that carries urine from the bladder out of the body. If the urethra receives too much radiation, patients may experience urinary side effects.

Current CT scans used for treatment planning do not clearly show the urethra unless a urinary catheter is inserted. While a catheter can improve visibility, it may cause discomfort, increase the risk of infection, and slightly change the natural position of the urethra. MRI scans can also help visualize the urethra, but they are not always available and may not fit easily into all treatment workflows.

Photon-counting CT (PCCT) is a new type of CT scanner that produces higher-quality images with better detail. This technology may allow doctors to see the urethra without using a catheter.

The purpose of this pilot study is to investigate whether PCCT can reliably visualize the urethra in prostate cancer patients without the need for catheter insertion. If successful, this approach could make treatment planning more comfortable and less invasive while helping doctors better protect healthy tissues during radiotherapy.