Diagnosis and Risk Assessment of Locally Advanced Rectal Cancer Using Co-registered Ultrasound and Photoacoustic Imaging
Washington University School of Medicine
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.
Description
The 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. The proposed new imaging technique combined with deep-learning algorithms will provide a real-time imaging tool to assist surgeons in predicting the neoadjuvant treatment response of rectal cancer patients. Such a tool will offer sensitive vascular and %sO2 contrast for identifying complete responses, thereby assisting su…
Eligibility
- Age range
- 19+ years
- Sex
- All
- Healthy volunteers
- No
Inclusion Criteria Patients: * Patients with any stage of rectal cancer undergoing surgical resection. * Age \>18 years * Able to provide informed consent Additional Inclusion Criterion for in vivo imaging (patients): * Lesion located within 15cm of the anal verge Exclusion Criteria Patients: * 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.
Interventions
- DevicePhotoacoustic 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.
- DeviceEndorectal 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.
- OtherReader 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.
Location
- Washington University School of MedicineSt Louis, Missouri