Photon-Counting Computed Tomography-Based Urethral Visualization Without Catheterization for Radiotherapy Planning: A Prospective Pilot Study Under ANTHEM (PURE-CT/ANTHEM)

July 23, 2026 updated by: Istituto Clinico Humanitas

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.

Study Overview

Status

Recruiting

Conditions

Prostate Cancer

Intervention / Treatment

Other: image acquisition

Study Type

Observational

Enrollment (Estimated)

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Name: Ciro Franzese, MD, Radiation Oncologist
Phone Number: +39 0282247454
Email: ciro.franzese@hunimed.eu

Study Contact Backup

Name: Laura Bonavita, Master degree
Phone Number: +39 0282247026
Email: laura.bonavita@humanitas.it

Study Locations

Italy
- Milan
  - Rozzano, Milan, Italy, 20089
    - Recruiting
    - IRCCS Humanitas Research Hospital
    - Contact:
      
      Ciro Franzese, MD, Radiation Oncologist
      
      Phone Number: +39 0282247454
      
      Email: ciro.franzese@hunimed.eu
    - Contact:
      
      Laura Bonavita, Master degree
      
      Phone Number: +39 0282247026
      
      Email: laura.bonavita@humanitas.it

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

Adult
Older Adult

Accepts Healthy Volunteers

Sampling Method

Non-Probability Sample

Study Population

patient with prostate cancer with indication to radiotherapy treatment

Description

Inclusion Criteria:

Prostate cancer candidate to radiotherapy
Written informed consent.
Eligibility for urethral catheter placement according to institutional practice

Exclusion Criteria:

Active or suspected urinary tract infection.
Known urethral stricture or recent urethral surgery
Contraindication to catheter placement.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
quality of imaging Time Frame: Day of TC acquisition	Quantitative quality of prostatic urethra contouring on non-catheter photon-counting CT, assessed using spatial overlap and boundary agreement metrics, specifically the Dice similarity coefficient (DSC) and the 95th percentile Hausdorff distance (HD95), with corresponding confidence intervals.	Day of TC acquisition

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
evaluate inter-observer agreement of urethral contours generated on non-catheter PCCT Time Frame: immediately after TC acquisition	Inter-observer agreement assessed using spatial overlap and distance-based metrics (DSC and HD95).	immediately after TC acquisition
compare non-catheter urethral contours with catheter-based reference contours Time Frame: immediately after TC acquisition	Agreement between non-catheter and catheter-based contours using spatial and geometric metrics (DSC and HD95).	immediately after TC acquisition
assess contouring confidence and contouring time across different PCCT reconstruction approaches Time Frame: immediately after TC acquisition	Contour confidence score and contour time compared to standardized clinical times	immediately after TC acquisition
explore segmental urethral visualization along its anatomical course. Time Frame: immediately after TC acquisition	evaluating segment-specific visualization quality through image quality parameters and artifacts affecting visualization	immediately after TC acquisition
Quantitative contour-derived parameters Time Frame: immediately after TC acquisition	explore quantitative imaging and contour-derived parameters related to urethral conspicuity and reproducibility	immediately after TC acquisition

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Istituto Clinico Humanitas

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Willemink MJ, Persson M, Pourmorteza A, Pelc NJ, Fleischmann D. Photon-counting CT: Technical Principles and Clinical Prospects. Radiology. 2018 Nov;289(2):293-312. doi: 10.1148/radiol.2018172656. Epub 2018 Sep 4.
Shah KD, Zhou J, Roper J, Dhabaan A, Al-Hallaq H, Pourmorteza A, Yang X. Photon-counting CT in cancer radiotherapy: technological advances and clinical benefits. Phys Med Biol. 2025 May 16;70(10):10TR01. doi: 10.1088/1361-6560/add4ba.
Yoshimura T, Okubo K, Takase Y, et al. Visualizing the urethra by magnetic resonance imaging without catheterization: Post-urination MRI technique. European Journal of Radiology Open. 2021 Jul;8:100382
Ong WL, Allan Hupman M, Davidson M, Ruschin M, Detsky J, Liu S, Vesprini D, Loblaw A. Urethra contouring on computed tomography urethrogram versus magnetic resonance imaging for stereotactic body radiotherapy in prostate cancer. Clin Transl Radiat Oncol. 2023 Dec 30;45:100722. doi: 10.1016/j.ctro.2023.100722. eCollection 2024 Mar.

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

June 22, 2026

Primary Completion (Estimated)

December 31, 2026

Study Completion (Estimated)

December 31, 2026

Study Registration Dates

First Submitted

June 24, 2026

First Submitted That Met QC Criteria

July 23, 2026

First Posted (Actual)

July 28, 2026

Study Record Updates

Last Update Posted (Actual)