Imaging for colon cancer
No systematic review has been performed on this topic. The guidance below is based on current international guidelines and consensus statements considered to be relevant to Australian practice.
Imaging is an important part of staging patients with colon cancer.
Staging investigations should preferentially be performed pre-operatively in patients diagnosed with a colon cancer at colonoscopy or computed tomography (CT) colonography. Some patients may have a colon cancer diagnosed by CT scan if they present emergently with obstruction. Others may require postoperative staging investigations after an emergency operation.
Imaging should be reported in conjunction with the patient’s clinical circumstances and previous imaging, to prevent incorrect attribution of lesions as metastases. Imaging should be reviewed at the colorectal multidisciplinary team meeting.
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Overview of evidence (non-systematic literature review)[edit source]
No systematic reviews were undertaken for this topic. Practice points were based on selected evidence and guidelines. Please see Guidelines Development for more information.
Initial staging investigations[edit source]
CT of chest, abdomen and pelvis[edit source]
The report should identify and describe all of the following:
- location, size and local extent of the primary lesion
- invasion into adjacent structures which may affect surgical planning
- complications such as local perforation and bowel obstruction
- locoregional lymph nodes (pericolic and local drainage)
- metastatic lymph nodes (retroperitoneal, pelvic and inguinal)
- visceral (lung and liver) and peritoneal metastatic disease.
Alternative modalities[edit source]
If a patient cannot have intravenous contrast, any of the following staging investigations may be used:
- non-contrast CT of the chest, abdomen and pelvis, plus ultrasound of the liver
- non-contrast CT chest, abdomen and pelvis, plus magnetic resonance imaging (MRI) of the liver
- MRI of the abdomen and pelvis.
Further staging investigations[edit source]
CT colonoscopy should be considered for a patient with colon cancer if it has not been possible to view the entire colon by colonoscopy due to the risk of synchronous tumours. (New Zealand Guidelines Group 2011.)
MRI of the liver is not part of routine pre-operative staging of colorectal cancer and is not funded by the Medicare Benefits Scheme (MBS). If there is metastatic disease confined to the liver on CT scan, an MRI of the liver can be considered to assess suitability for surgical resection. Many Australian hepatobiliary surgeons will order a post-contrast MRI of the liver, due to its proven increased sensitivity for small liver metastases, compared with CT and positron emission tomography-CT (PET-CT). This is particularly important in cases where the background liver parenchyma is abnormal, the patient has recently received chemotherapy, or when a patient cannot have iodinated contrast.
PET-CT imaging is not routinely indicated, nor MBS funded, for pre-operative staging of colorectal cancer. It is recommended to detect additional metastases in patients with colorectal cancer who have potentially resectable lung and liver metastases and is MBS funded for suspected residual, metastatic or recurrent colorectal cancer in a patient for whom active therapy is being considered.
For patients with colorectal cancer who have potentially resectable metastatic disease, PET-CT is recommended to detect additional metastases.
Surveillance imaging[edit source]
There is no standardised protocol in Australia for surveillance imaging. There is significant evidence from clinical trials to support integration of imaging into routine follow-up, in addition to clinical follow-up including liver function tests and carcinoembryonic antigen (CEA) measurement. Any follow up imaging should be compared with previous imaging.
International recommendations for surveillance protocols vary. The most frequently followed guidelines in Australia are the American Society of Clinical Oncology (ASCO) and European Society of Medical Oncology (ESMO) guidelines.
ASCO guidelines recommend that, for those colon and rectal cancer patients at higher risk of recurrence and where curative intent was an option, CT imaging of the chest and abdomen should be undertaken annually for 3 years. A pelvic CT should be considered for rectal cancer surveillance, especially for those who had not received radiotherapy.
ESMO guidelines recommend that a CT scan of chest and abdomen every 6–12 months for the first 3 years be considered in patients who are at higher risk of recurrence. Contrast-enhanced ultrasound (CEUS) could substitute for abdominal CT scan. Other radiological examinations are of unproven benefit and must be restricted to patients with suspicious symptoms.
Table 7.1 shows the surveillance schedule proposed by an ESMO consensus conference, based on ASCO and European guidelines. Twelve-monthly scanning would be more typical in stage II and III surveillance, and 6-monthly scanning for resected stage IV disease based on higher risk of recurrence.
Table 7.1 CAP surveillance schedule for high-risk colorectal cancer proposed by ESMO[edit source]
|Stage||Time after surgery or adjuvant treatment (months)|
Adapted from Schmoll et al 2012
CAP: CT of chest, abdomen and pelvis
For patients with stage II and III disease who have undergone initial surgery and/or adjuvant treatment, a suitable approach to imaging surveillance may involve 12-monthly CT of chest, abdomen and pelvis.
For patients with stage IV disease who have undergone a resection procedure with curative intent, a suitable approach to imaging surveillance may involve CT of chest, abdomen and pelvis every 6 months.
See Follow-up after curative resection for colorectal cancer chapter for further information regarding surveillance imaging.
- National Institute for Health and Care Excellence. Colorectal cancer: The Diagnosis and Management of colorectal cancer. United Kingdom: National Institute for Health and Care Excellence; 2014.
- New Zealand Guidelines Group. Colorectal cancer: Management of Early Colorectal Cancer. Wellington: Ministry of Health; 2011.
- National Comprehensive Cancer Network. NCCN Guidelines: Colon Cancer. National Comprehensive Cancer Network; 2016.
- Radiologists TRCo. Recommendations for cross-sectional imaging in cancer management - colon, rectum and anal cancer. Radiologists TRCo; 2014.
- Vreugdenburg TD, Ma N, Duncan JK, Riitano D, Cameron AL, Maddern GJ. Comparative diagnostic accuracy of hepatocyte-specific gadoxetic acid (Gd-EOB-DTPA) enhanced MR imaging and contrast enhanced CT for the detection of liver metastases: a systematic review and meta-analysis. Int J Colorectal Dis 2016 Nov;31(11):1739-1749 Available from: http://www.ncbi.nlm.nih.gov/pubmed/27682648.
- National Collaborating Centre for Cancer. The Diagnosis and Management of Colorectal Cancer - Evidence review United Kingdom: National Institute for Health and Care Excellence; 2011.;.
- Meyerhardt JA, Mangu PB, Flynn PJ, Korde L, Loprinzi CL, Minsky BD, et al. Follow-up care, surveillance protocol, and secondary prevention measures for survivors of colorectal cancer: American Society of Clinical Oncology clinical practice guideline endorsement. J Clin Oncol 2013 Dec 10;31(35):4465-70 Available from: http://www.ncbi.nlm.nih.gov/pubmed/24220554.
- Labianca R, Nordlinger B, Beretta GD, Mosconi S, Mandalà M, Cervantes A, et al. Early colon cancer: ESMO Clinical Practice Guidelines for diagnosis, treatment and follow-up. Ann Oncol 2013 Oct;24 Suppl 6:vi64-72 Available from: http://www.ncbi.nlm.nih.gov/pubmed/24078664.
- Schmoll HJ, Van Cutsem E, Stein A, Valentini V, Glimelius B, Haustermans K, et al. ESMO Consensus Guidelines for management of patients with colon and rectal cancer. a personalized approach to clinical decision making. Ann Oncol 2012 Oct;23(10):2479-516 Available from: http://www.ncbi.nlm.nih.gov/pubmed/23012255.