NCT04339374

Brief Summary

The purpose of this study is to demonstrate the functionality of a novel endorectal photoacoustic ultrasound imaging modality in humans with rectal cancer. The study involves testing a previously developed endorectal device to determine its ability to accurately assess rectal tumor response to preoperative treatment. Investigators hypothesize that a co-registered photoacoustic ultrasound endorectal device can significantly reduce unnecessary surgeries in rectal cancer patients with complete clinical response while maintaining high sensitivity in identifying those with residual cancer.

Trial Health

77
On Track

Trial Health Score

Automated assessment based on enrollment pace, timeline, and geographic reach

Enrollment
90

participants targeted

Target at P50-P75 for not_applicable

Timeline
32mo left

Started May 2023

Longer than P75 for not_applicable

Geographic Reach
1 country

1 active site

Status
recruiting

Health score is calculated from publicly available data and should be used for screening purposes only.

Trial Relationships

Click on a node to explore related trials.

Study Timeline

Key milestones and dates

Study Progress54%
May 2023Dec 2028

First Submitted

Initial submission to the registry

March 30, 2020

Completed
10 days until next milestone

First Posted

Study publicly available on registry

April 9, 2020

Completed
3.1 years until next milestone

Study Start

First participant enrolled

May 1, 2023

Completed
5.7 years until next milestone

Primary Completion

Last participant's last visit for primary outcome

December 31, 2028

Expected
Same day until next milestone

Study Completion

Last participant's last visit for all outcomes

December 31, 2028

Last Updated

February 12, 2026

Status Verified

February 1, 2026

Enrollment Period

5.7 years

First QC Date

March 30, 2020

Last Update Submit

February 9, 2026

Conditions

Rectal CancerColorectal Cancer

Keywords

Rectal cancerNonoperative managementWatch and waitComplete clinical response

Outcome Measures

Primary Outcomes (2)

  • Number of patients that readers are able to diagnose with rectal cancer

    The primary endpoint is to see if the readers trained to use the co-registered PAM/US data are able to diagnose rectal cancers with better sensitivity \& specificity using surgery pathology results as the ground truth. SOC sensitivity and specificity will be computed based on readers' cCR vs. non-cCR. The sensitivity and specificity with additional PAM/US data will be computed based on readers' revised cCR vs. non-cCR. PAM/US model sensitivity and specificity will also be computed using surgery pathology results.

    Approximately 15 minutes

  • Number of patients without surgery who cleared as cCR after 2-years of follow-up

    The secondary primary endpoint is the sensitivity and specificity of readers' cCR vs. non-cCR assessments using SOC and sensitivity and specificity of PAM/US models cCR vs. non-cCR reassessments PAM/US data. The "ground truth " of this cohort will be no cancer recurrence based on clinical data.

    2-years of follow-up

Secondary Outcomes (6)

  • Area under the receiver operating curve (ROC)

    Approximately 15 minutes

  • Characterize in vivo tissue samples with photoacoustic imaging

    Approximately 15 minutes

  • Performance characteristics of the novel endorectal ultrasound probe as measured by number of adverse events

    Approximately 15 minutes

  • Performance characteristics of the novel endorectal ultrasound probe as measured by evidence of tissue damage from the imaging laser

    Approximately 15 minutes

  • Performance characteristics of the novel endorectal ultrasound probe as measured by time required to complete study

    Approximately 15 minutes

  • +1 more secondary outcomes

Study Arms (2)

In vivo imaging

OTHER

* Patients with distal rectal lesions (benign or malignant tumors within 15cm of the anal verge) will be enrolled for the in vivo imaging portion of the study * Participation will include an intraoperative, in vivo evaluation of the tumor with a novel endorectal photoacoustic ultrasound probe. Following the induction of anesthesia, patients will undergo a 20-minute endorectal imaging evaluation performed by their colorectal surgeon. After imaging, the patient will then undergo standard-of-care surgical resection of the rectum. The resection specimen may then be imaged ex vivo as deemed necessary. * For this portion of the study, enrollment will be limited to a total of 86 participants

Device: Photoacoustic imaging, photoacoustic microscopyDevice: Endorectal photoacoustic imaging probe

Reader Team

EXPERIMENTAL

3 surgeons and 1 radiologist will be initially trained to grade lesions using the PAM/US image from the first set of 30 patients (Group 1). They will then use the PAM/US data to grade lesions obtained from the second set of 56 patients after initial training (Group 2).

Device: Photoacoustic imaging, photoacoustic microscopyDevice: Endorectal photoacoustic imaging probeOther: Reader Performance

Interventions

Photoacoustic imaging, photoacoustic microscopyDEVICE

-Emerging technique in which a short-pulsed laser beam penetrates diffusely into a tissue sample, causing the release of acoustic waves due to a transient temperature rise -The transient acoustic waves, or photoacoustic waves, are then measured around the sample by US transducers -The resolution of the devices can be altered by changing the wavelengths of laser light and spectrum analysis of the receiver. In this manner, human colorectal pathology will be examined under multiple types of photoacoustic ranges (broadly termed photoacoustic microscopy and photoacoustic imaging). The study has two phases. In the second phase, the investigators will provide assessments of treated rectum based on clinical information and photoacoustic information after initial training.

Also known as: PAI, PAM
In vivo imagingReader Team
Endorectal photoacoustic imaging probeDEVICE

-An endorectal imaging device using coregistered photoacoustic and ultrasound imaging has been constructed. This probe is used to perform in vivo imaging among patients with rectal pathology intraoperatively.

Also known as: PAI, Coregistered photoacoustic ultrasound imaging, PAM
In vivo imagingReader Team
Reader PerformanceOTHER

After initial training using Group 1 data, readers will classify lesions as non-clinical complete responders (non-cCR) or clinical complete responders (cCR) based on standard-of-care (SOC) information. Following PAM/US imaging, readers will reassess lesion status using PAM/US data. PAM/US model outputs will be generated for each patient and compared with reader assessments. For patients undergoing surgery, tumor regression scores from surgical specimens will be compared with reader assessments and model outputs. For patients under nonoperative surveillance, clinical response at 2-year follow-up will be compared with model outputs. The study will evaluate whether PAM/US assistance improves residual tumor detection in Group 2 patients. As the model is under development, it will be iteratively retrained and tested as new data become available.

Reader Team

Eligibility Criteria

Age19 Years+
Sexall
Healthy VolunteersNo
Age GroupsAdult (18-64), Older Adult (65+)

You may qualify if:

  • Patients with any stage of rectal cancer undergoing surgical resection.
  • Age \>18 years
  • Able to provide informed consent
  • Lesion located within 15cm of the anal verge

You may not qualify if:

  • Inability to provide consent
  • Collection of intraoperative specimen for frozen section analysis will disqualify patients from participation
  • Eligibility Criteria Readers:
  • Colorectal surgeons or radiologists who treat or interpret imaging regularly for patients with rectal cancer.

Contact the study team to confirm eligibility.

Sponsors & Collaborators

Study Sites (1)

Washington University School of Medicine

St Louis, Missouri, 63110, United States

RECRUITING

Related Publications (1)

  • Leng X, Uddin KMS, Chapman W Jr, Luo H, Kou S, Amidi E, Yang G, Chatterjee D, Shetty A, Hunt S, Mutch M, Zhu Q. Assessing Rectal Cancer Treatment Response Using Coregistered Endorectal Photoacoustic and US Imaging Paired with Deep Learning. Radiology. 2021 May;299(2):349-358. doi: 10.1148/radiol.2021202208. Epub 2021 Mar 23.

    PMID: 33754826DERIVED

Related Links

MeSH Terms

Conditions

Rectal NeoplasmsColorectal Neoplasms

Condition Hierarchy (Ancestors)

Intestinal NeoplasmsGastrointestinal NeoplasmsDigestive System NeoplasmsNeoplasms by SiteNeoplasmsDigestive System DiseasesGastrointestinal DiseasesIntestinal DiseasesRectal DiseasesColonic Diseases

Study Officials

  • William Chapman, Jr., M.D.

    Washington University School of Medicine

    PRINCIPAL INVESTIGATOR

Central Study Contacts

William Chapman, Jr., M.D.

CONTACT

314-454-7177chapmanjr@wustl.edu

Study Design

Study Type
interventional
Phase
not applicable
Allocation
NON RANDOMIZED
Masking
NONE
Purpose
OTHER
Intervention Model
PARALLEL
Sponsor Type
OTHER
Responsible Party
SPONSOR

Study Record Dates

First Submitted

March 30, 2020

First Posted

April 9, 2020

Study Start

May 1, 2023

Primary Completion (Estimated)

December 31, 2028

Study Completion (Estimated)

December 31, 2028

Last Updated

February 12, 2026

Record last verified: 2026-02

Data Sharing

IPD Sharing
Will share

* Data available for sharing - Code and de-identified patient data related to this project will be made available upon request to other academic entities following the publication of project-related results. * Data to be shared - Individual participant data, along with code related to the novel neural network developed, that underlie the results reported herein. Data will not be shared until deidentified. * With whom will data be shared - academic entities approved by the primary research team

Shared Documents
STUDY PROTOCOL
Time Frame
Data will be made available to approved persons between 12 and 36 months after publication of these results
Access Criteria
* Purpose of accessing data - any purpose allowed. * Mechanism for sharing data - data to be shared via institutional file sharing service once appropriate parties have been approved by the research team.

Locations

US(1)