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Completed

NCT Number: NCT04565457

A Pilot Study Evaluating the Effect of 2D Antiscatter Grids on CBCT Image Quality

This is Pilot study that investigates the CBCT(Cone beam computed tomography) image quality improvement provided by the 2D antiscatter grid technology. The primary objective is to assess the improvement in tissue visualization in an observer study, which will be conducted in a blinded fashion.

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Key information

Conditions

Prostate Cancer Genital Diseases Genital Diseases, Male Genital Neoplasms, Male Head and Neck Cancers Head and Neck Neoplasms Male Urogenital Diseases Neoplasms Neoplasms by Site Prostatic Diseases Prostatic Neoplasms Upper Abdomen Cancers Urogenital Diseases Urogenital Neoplasms

Age range

18 year–100 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

University of Colorado Hospital, Aurora, Colorado, United States

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About this study

This is a single arm study, where all participants will be scanned with a CBCT system equipped with 2D antiscatter grid technology, referred to as research CBCT. Each participant will also be scanned with a standard clinical CBCT as part of their standard clinical care, which will serve as the baseline, or control. Thus, the image quality improvement in research CBCT will assessed with respect to standard clinical CBCT.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Provision to sign and date the consent form.
  • Stated willingness to comply with all study procedures and be available for the duration of the study.
  • Be a male or female aged 18-100.
  • Participants who will be treated or are currently being treated with CBCT-guided photon therapy for prostate or prostate-bed, abdomen head and neck, or pelvic cancers, or with image-guided proton therapy for prostate or prostate bed cancer.

Exclusion criteria

  • Metallic implants in the CBCT scan volume, such as hip prostheses or spine stabilization hardware. Patients with pacemakers, defibrillators, or other implanted electronic devices. Dental implants, fillings, or fiducial markers may be acceptable, and the decision for inclusion/exclusion will be on a case-by-case basis, by reviewing prior CT images of the study candidate. Patient's prior CT images will be reviewed by the PI or the site PI.
  • Patients who do not have the ability to lie still for the duration of his/her CBCT imaging and treatment should be excluded. If image artifacts in prior scans are deemed excessive, the patient will be excluded from the study.
  • Known pregnancy. (Per SOC, a pregnancy test will be performed prior to CBCT scan on Day 1. At this time, women of child-bearing potential (WOCBP) will receive a pregnancy test to re-confirm eligibility).
  • Women of child-bearing potential are described as:
  • Age 55 or younger who have not had a negative pregnancy test within 3 days. This excludes patients who have had tubal ligation or are already post-menopausal.

Treatment and study plan

Research CBCT

Device

Each study participant will receive one additional CBCT scan, with 2D antiscatter grid in place. This is the only intervention in the study, referred as research CBCT scan, and it will be performed on one of the days during the participant's radiation treatment course. This additional research CBCT scan will be used strictly for the objectives of this study. It will not be used as part of the standard clinical care, such as imaging guidance of participant's radiation treatment or diagnostic purposes. To deliver participant's radiation treatment under CBCT guidance, a standard clinical CBCT scan will be acquired, as in standard clinical care protocols.

Primary outcomes

  1. Ratio of Standard CBCT to Research CBCT HU Error in Photon Therapy Participants

    Time frame: At time of CBCT imaging session (Day 1)

    Ratio of HU error for standard clinical CBCT (iteratively reconstructed) relative to research CBCT with 2D antiscatter grid in photon therapy participants. HU error was assessed in corresponding regions of interest, and the ratio was estimated using a linear mixed-effects model. A ratio greater than 1 would indicate higher HU error in standard CBCT than in research CBCT. A ratio less than 1 would indicate higher HU error in research CBCT than in standard CBCT.

  2. Median Shift in Hounsfield Unit (HU) Error Between Standard CBCT and Research CBCT in Proton Therapy Participants

    Time frame: At time of CBCT imaging session (Day 1)

    Median paired shift in Hounsfield Unit (HU) error between research CBCT and standard clinical CBCT scans in participants receiving proton radiation therapy. HU error was evaluated in corresponding regions of interest in paired scans. The Hodges-Lehmann estimate of the median shift and its 95% confidence interval were calculated, and paired differences were evaluated using a Wilcoxon signed-rank test.

  3. Ratio of Artifact Amplitude Between Standard CBCT and Research CBCT in Photon Therapy Participants

    Time frame: At time of CBCT imaging session (Day 1)

    Ratio of artifact amplitude between standard clinical CBCT (iteratively reconstructed) and research CBCT scans in participants receiving photon radiation therapy. Artifact amplitude was measured in corresponding regions of interest. The ratio of artifact amplitude between standard CBCT and research CBCT was estimated using a linear mixed-effects model. Ratio greater than 1 would indicate that standard CBCT has greater artifact amplitude than research CBCT.

  4. Median Shift in Artifact Amplitude (Measured in Hounsfield Units) Between Standard CBCT and Research CBCT in Proton Therapy Participants

    Time frame: At time of CBCT imaging session (Day 1)

    Median paired shift in Artifact Amplitude between research CBCT and standard clinical CBCT scans in participants receiving proton radiation therapy. Artifact Amplitude error was evaluated in corresponding regions of interest in paired scans. The Hodges-Lehmann estimate of the median shift and its 95% confidence interval were calculated, and paired differences were evaluated using a Wilcoxon signed-rank test.

  5. Ratio of Contrast-To-Noise Ratio (CNR) Between Standard CBCT and Research CBCT in Photon Therapy Participants

    Time frame: At time of CBCT imaging session (Day 1)

    Ratio of CNR between standard clinical CBCT and research CBCT scans in participants receiving photon radiation therapy. CNR was quantified in corresponding regions of interest in paired standard and research CBCT scans of each participant. The ratio of CNR between standard CBCT and research CBCT was estimated using a linear mixed-effects model.

  6. Median Shift in Contrast to Noise Ratio (CNR) Between Standard CBCT and Research CBCT in Proton Therapy Participants

    Time frame: At time of CBCT imaging session (Day 1)

    Median paired shift in CNR between research CBCT and standard clinical CBCT scans in participants receiving proton radiation therapy. CNR was evaluated in corresponding regions of interest in paired scans. The Hodges-Lehmann estimate of the median shift and its 95% confidence interval were calculated, and paired differences were evaluated using a Wilcoxon signed-rank test.

Secondary outcomes

  1. Accuracy of Automated Tissue Delineation in CBCT Images for Photon Therapy Participants. Difference in Dice Similarity Coefficient Between Research CBCT and Standard CBCT

    Time frame: At time of CBCT imaging session.

    Similarity between anatomical structures delineated by auto-segmentation software and expert observer contours in research CBCT and standard clinical CBCT images was evaluated using the Dice similarity coefficient. The pairwise difference in Dice coefficients between standard clinical CBCT and research CBCT images was calculated. Higher Dice coefficients indicate greater similarity between auto-segmented and expert-drawn contours and higher accuracy in automated tissue delineation.

Sponsors and collaborators

Lead sponsor

University of Colorado, Denver

Other

Collaborators

  • National Cancer Institute (NCI)

Registry information

Important dates

Study start
2023
Primary completion
2025
Study completion
2025
First posted
Sep 25, 2020
Registry last updated
May 6, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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