Ultrasound and Photoacoustic Imaging for Enhanced Differential Diagnosis of Rectal Cancer

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.

Conditions

• Rectal Cancer
• Colorectal Cancer

Interventions

DEVICE

Photoacoustic imaging, photoacoustic microscopy

-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.

DEVICE

Endorectal photoacoustic imaging probe

-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.

OTHER

Reader Performance

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.

Sponsors & Collaborators

• National Institute for Biomedical Imaging and Bioengineering (NIBIB)

  collaborator NIH

• Washington University School of Medicine

  lead OTHER

Principal Investigators

• William Chapman, Jr., M.D. · Washington University School of Medicine

Study Design

Allocation

NON_RANDOMIZED

Purpose

OTHER

Masking

NONE

Model

PARALLEL

Eligibility

Min Age

19 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2023-05-01

Primary Completion

2028-12-31

Completion

2028-12-31

FDA Device

Yes

Countries

• United States

Study Locations