PET/MR for Rectal Cancer Treatment Monitoring and Surveillance

Not Applicable

Terminated

Brief Summary: The goal of pilot study is to assess the feasibility of FDG-PET/MRI for monitoring rectal cancer disease status in the setting of rectal cancer non-operative management (NOM). Data from this study will be used to guide the design of future clinical trials involving FDG-PET/MRI for rectal cancer NOM.

Recruitment & Eligibility

Inclusion Criteria

At least 18 years of age
Biopsy-proven rectal adenocarcinoma of the rectum with clinically suspected or previously known stage I-IIIB (cT1-4, N0-2, M0) disease
Anticipated or prior chemoradiation as part of an NOM treatment strategy
Ability to understand and willingness to sign an IRB-approved written informed consent document

Exclusion Criteria

Prior surgical resection of rectal cancer (endoscopic or TME)
Contraindication to MRI
Comorbidities that would limit patient's ability to cooperate with a PET/MRI examination (e.g. dementia, inability to follow commands, claustrophobia, tremors, requirement for oxygen by nasal cannula, etc...).
Implanted devices or materials that may interfere with MRI imaging or create significant artifact
Pregnancy
Contraindication to gadolinium contrast or FDG
End-stage renal disease

Primary Outcome Measures

Name	Time	Method
Technical Feasibility of PET/MRI as Measured by the Completion of the Study With Acceptable Image Quality in ≥70% of Scans	Up to 12 months after completion of enrollment of all patients (26 months)	-For patients imaged at multiple time points after enrollment, all available PET/MRIs will be included in the feasibility analysis. Patients able to remain on the scanner for the full duration of the planned data acquisition without any serious adverse events will be considered to have completed the PET/MRI rectal cancer protocol. Image quality will be assessed by the Principal Investigator on review at a dedicated workstation with specialized PET/MR software. A standardized Likert-based scoring scheme will be utilized to capture subjective assessments of image contrast (1 = worst; 5 = best), image resolution (1 = worst; 5 = best), and image artifact 'freeness' (1 = worst; 5 = best). Image sets scoring ≥ 3 in all three categories will be considered of acceptable quality.

Secondary Outcome Measures

Name	Time	Method
Percentage of Scans With Changes in Perceived Disease Status as Measured by PET/MRI Tumor Regression Grade Relative to the Conventional MRI Only Tumor Regression Grade	Up to 12 months after completion of enrollment of all patients (26 months)	* The study reader will interpret the MRI for the tumor regression grade and then will interpret the PET/MRI for the tumor regression grade. * The tumor regression grade is a five-tier imaging-based scoring system based on the ability to distinguish between tumor and fibrosis. mrTRG 1, low signal fibrosis only, no tumor signal; mrTRG 2, more than 75 per cent fibrosis and minimal tumor signal intensity; mrTRG 3, 50 per cent tumor/fibrosis; mrTRG 4, less than 25 per cent fibrosis, predominant tumor signal; and mrTRG 5, no fibrosis

Locations (1): Washington University School of Medicine
🇺🇸
Saint Louis, Missouri, United States
Washington University School of Medicine
🇺🇸Saint Louis, Missouri, United States