Ultrasound and Photoacoustic Imaging of Colon and Rectal Tumor Tissue

Recruiting

• Conditions: Rectal Cancer; Colon Cancer; Adenomatous Polyps
• Interventions: Device: Photoacoustic imaging, photoacoustic microscopy; Device: Endorectal photoacoustic imaging probe

• Registration Number: NCT04339374
• Lead Sponsor: Washington University School of Medicine

Brief Summary

The purpose of this pilot study is to a) explore the photoacoustic properties of normal, polypoid, and malignant colorectal tissue and b) demonstrate the functionality of a novel endorectal photoacoustic ultrasound probe in humans with rectal cancer. The study includes two parts. The initial exploratory portion will be conducted ex vivo with resected colon and rectal specimens immediately following surgical excision. Based on those findings, an endorectal probe will then be constructed to examine in vivo tumors. The investigators hypothesize that in vivo photoacoustic imaging will be capable of differentiating normal from malignant tissue.

Detailed Description

Not available

Basic Information
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Recruitment & Eligibility
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Study & Design
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Trial Locations

Study Timeline

• Study Start: 2017-08-11
• Study First Submitted: 2020-03-30
• Study First Submitted QC: 2020-04-03
• Study First Posted: 2020-04-09
• Status Verified: 2024-11
• Last Update Submitted: 2024-11-04
• Last Update Posted: 2024-11-06
• Primary Completion: 2025-06-30
• Study Completion: 2025-06-30

Recruitment & Eligibility

• Status: RECRUITING
• Sex: All
• Target Recruitment: 200

Inclusion Criteria

• Patients with any stage colon or rectal cancer or adenomatous polyp undergoing surgical resection whose specimens do not undergo intraoperative frozen section analysis
• Age >18 years
• Able to provide informed consent
• Patients with pre-treatment MRI and re-staging MRI before surgery (retrospective review)

Additional Inclusion Criterion for in vivo imaging

• Lesion located within 15cm of the anal verge

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Exclusion Criteria

• Inability to provide consent
• Collection of intraoperative specimen for frozen section analysis will disqualify patients from participation

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Study & Design

• Study Type: OBSERVATIONAL
• Study Design: Not specified

Arm && Interventions

Group	Intervention	Description
Ex vivo imaging	Photoacoustic imaging, photoacoustic microscopy	* Patients with known adenomatous polyps or malignancies in the colon or rectum undergoing resection will be considered for enrollment * Participation will include imaging of both normal and known pathologic portions of the specimen ex vivo immediately following resection. The specimen will then undergo fixation and standard pathologic evaluation, with subsequent correlation between imaging and pathologic findings. * This data will also be used to develop a convolutional neural network (CNN) to assist in interpreting photoacoustic imaging data.
In vivo imaging	Photoacoustic imaging, photoacoustic microscopy	* 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 as well as ex vivo imaging post-resection as described above. 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 will then be imaged ex vivo as performed in the "ex vivo cohort" of this study. * For this portion of the pilot, enrollment will be limited to 40 participants
Ex vivo imaging	Endorectal photoacoustic imaging probe	* Patients with known adenomatous polyps or malignancies in the colon or rectum undergoing resection will be considered for enrollment * Participation will include imaging of both normal and known pathologic portions of the specimen ex vivo immediately following resection. The specimen will then undergo fixation and standard pathologic evaluation, with subsequent correlation between imaging and pathologic findings. * This data will also be used to develop a convolutional neural network (CNN) to assist in interpreting photoacoustic imaging data.
In vivo imaging	Endorectal photoacoustic imaging probe	* 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 as well as ex vivo imaging post-resection as described above. 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 will then be imaged ex vivo as performed in the "ex vivo cohort" of this study. * For this portion of the pilot, enrollment will be limited to 40 participants

Primary Outcome Measures

Name	Time	Method
Area under the receiver operating curve (ROC)	Approximately 60 minutes	-The purpose of this study is to develop and pilot imaging technology that will aid in the differentiation of malignant from normal colorectal tissue. As such, the primary endpoint is the differentiating capability of the endorectal coregistered probe, to be measured as the AUC or area under the receiver operating curve. This primary endpoint to be measured in both the ex vivo and in vivo portions of this study. This will also be used to compare performance of the classification neural network with ultrasound alone compared to ultrasound coupled with photoacoustic techniques.

Secondary Outcome Measures

Name	Time	Method
Performance characteristics of the novel endorectal ultrasound probe as measured by number of adverse events	Approximately 60 minutes
Performance characteristics of the novel endorectal ultrasound probe as measured by evidence of tissue damage from the imaging laser	Approximately 60 minutes
Performance characteristics of the novel endorectal ultrasound probe as measured by time required to complete study	Approximately 60 minutes
Performance characteristics of the novel endorectal ultrasound probe as measured by variability in image production	Approximately 60 minutes
Characterize both in and ex vivo tissue samples with photoacoustic imaging	Approximately 60 minutes	This outcome will be measured qualitatively by comparing histologic findings to the experimental imaging. The critical features to be analyzed in each image are the cross-sectional structure of normal colorectal tissues in comparison to the loss of a layered structure and its corresponding evenly distributed vascular pattern in the setting of neoplasia.

Trial Locations

Locations (1)

Washington University School of Medicine; 🇺🇸 Saint Louis, Missouri, United States