Reporting Colorectal Cancer

Colorectal cancer is the 4th most common cancer in the UK, with over 41000 new cases diagnosed per year. Incidence is rising, having increased by 14% since the 1970s, and is higher in men than women (Cancer Research UK).

PET-CT Scans Performed 2022-2023

At our institution, colorectal cancer accounts for 2% of all PET-CT scans performed.

The evidence-based indications for use of PET-CT in the UK 2016 list six indications for FDG PET-CT in colorectal cancer:

1. Staging of patients with synchronous metastases at presentation that are suitable for resection or patients with equivocal findings on other imaging; for example, pulmonary or liver lesions
2. Restaging of patients with recurrence being considered for radical treatment and/or invasive targeted techniques (for example, metastasectomy/selective internal radiation therapy [SIRT])
3. Assessment of treatment response in patients with rectal carcinoma post (chemo)radiotherapy with indeterminate findings on other imaging
4. Assessment of treatment response following targeted therapy (ablative techniques for liver or lung metastases, selective internal radiotherapy for liver metastases) in metastatic colorectal carcinoma when findings on other imaging are inconclusive
5. Detection of recurrence in patients with rising tumour markers and/or clinical suspicion of recurrence with normal or equivocal findings on other imaging
6. Evaluation of indeterminate pre-sacral masses post-treatment

The use of PET-CT in these indications will be studied in detail in this course, which is comprised of four modules, followed by a case-based assessment.

• Tutorial 1: Colorectal anatomy, PET-CT technique and patterns of physiological FDG uptake
• Tutorial 2: Assessment of patients with potentially resectable metastatic disease
• Tutorial 3: Restaging, suspected recurrence including rising tumour markers with normal/equivocal conventional diagnostic workup
• Tutorial 4: Response assessment and summary

Learning Objectives

• Describe the radiological anatomy of the colon, variations of physiological colorectal distribution of FDG and patterns of uptake associated with colorectal cancers
• Discuss the role of PET-CT and contrast enhanced MRI in the assessment of hepatic metastatic disease and PET-CT’s limitations in the assessment of colorectal metastases
• Explain the follow-up pathway of patients treated for colorectal cancer and the workup of suspected recurrence
• Discuss current evidence of PET-CT for local response assessment

Please note: To mark this course as complete on your Learning Dashboard and access your certificate of completion, you must finish all learning modules and submit the course evaluation.

Suitable for radiologists and nuclear medicine physicians who intend to train to report PET-CT, or who otherwise encounter these studies in their practice and wish to increase their confidence, for example in the role of a presenting radiologist at an MDT (Multi-Disciplinary Team).

References:

1. Evidence-based indications for the use of PET-CT in the United Kingdom 2022
2. Cancer Research UK. Accessed November 2023.