Pilot study of FAPI PET/CT for locoregional (re)staging of lymph nodes in colorectal carcinoma

Recruitment & Eligibility

Status: Recruiting

Sex: Not specified

Target Recruitment: 30

Inclusion Criteria

• Biopsy proven newly detected adenocarcinoma of the colon or rectum
• cT(any) N1-2 M(any) using TNM 8th edition and based on standard diagnostic
imaging including contrast enhanced-CT thorax-abdomen (for colon and rectum)
and pelvic MRI (for rectum)
• Indication for curative local treatment of the primary colon/rectal tumour
• Signed written informed consent prior to any study specific procedure

For colon cancer patients:
• Age 18 years and older
• Indication for surgery including resection of the colon tumour and the
corresponding mesentery
• Surgery can be planned within 5 weeks after diagnostic imaging
• Surgery takes place in one of the participating centres of this study

For rectal cancer patients:
• Age 50 years and older
• Indication for neoadjuvant (chemo)radiotherapy of the rectal tumour
• Planned for response assessment after (chemo)radiotherapy with pelvic MRI
• Planned for surgery or an organ preservation approach in one of the
participating centres of this study

Exclusion Criteria

• WHO 0-2
• Histopathology of mucinous adenocarcinoma
• Inability to provide informed consent
• Pregnancy
• Lactation, unable to substitute for 24 hours after FAPI PET/CT
• Known second malignant disease that may complicate image interpretation
including a second primary at time of diagnosis CRC
• Inability to cooperate with the scan process: inability to lie relatively
still and in supine for 30-60 minutes or patient body habitus above scanner
dimensions
• Suspicion of peritoneal metastases based on contrast-enhanced CT and/or MRI
abdomen
• Treatment setting without local treatment of the primary colorectal tumour

For colon cancer patients:
• Absence of diagnostic contrast enhanced-CT thorax-abdomen
• Refusal of surgery by the patient
• Indication for neoadjuvant treatment
• Indication for emergency surgery

For rectal cancer patients:
• Contra-indication for MRI
• Absence of diagnostic pelvic MRI and/or contrast enhanced-CT thorax-abdomen
• Refusal of neoadjuvant treatment by the patient
• Absence of response assessment after (chemo)radiotherapy

Study & Design

Study Type: Interventional

Study Design: Not specified

Primary Outcome Measures

Name	Time	Method
<p>The main objective is to describe the diagnostic accuracy of FAPI PET/CT in<br /><br>detecting regional lymph node metastases relative to standard of care<br /><br>diagnostic imaging. FAPI PET/CT will be visually correlated with<br /><br>contrast-enhanced CT in colon cancer patients, and pelvic MRI pre- and<br /><br>post-neoadjuvant treatment in rectal cancer patients. Histopathology of the<br /><br>resected specimen will serve as reference test for operated patients.</p><br>

Secondary Outcome Measures

Name	Time	Method
<p>Secondary outcomes include description of additional findings on FAPI PET/CT.<br /><br>Also, the correlation between tumour stroma in resected lymph node metastases<br /><br>and tracer uptake of regional lymph nodes on FAPI PET/CT including analyses of<br /><br>de FAP protein in the tumor stroma. Also, evaluation of response to neoadjuvant<br /><br>treatment on FAPI PET/CT in rectal cancer. All outcomes are descriptive and<br /><br>serve as pilot for a potential subsequent larger prospective diagnostic study.</p><br>