• Simunovic M, Stewart L, Zwaal C, Johnston M, Diagnostic Imaging Guidelines Panel. Cross-sectional imaging in colorectal cancer: recommendations report. Toronto (ON): Cancer Care Ontario (CCO); 2006 Apr 12. 19 p. [47 references]

Staging

• Prior to surgery, patients with colon cancer should have full staging including adequate images of the chest (i.e., an x-ray) and abdomen.
• Prior to surgery, patients with rectal cancer should have full staging including adequate images of the chest (i.e., an x-ray), abdomen and pelvis.
• Computed tomography (CT) or magnetic resonance imaging (MRI) scanning of the abdomen is recommended over ultrasound for detecting liver metastases.
• CT or MRI of the pelvis should be done to assess mesorectal margin status.
• If T and N category determinations will drive decisions on the use of neoadjuvant therapy, transrectal ultrasound or MRI with endorectal coil is recommended. Operator skill is more likely to influence the accuracy of transrectal ultrasound versus MRI with endorectal coil. It is likely that advances in technology will demonstrate similar staging accuracy for routine MRI versus MRI with endorectal coil.

Response

There is no evidence on the use of cross-sectional imaging to assess response to chemotherapy or radiotherapy in patients with colorectal cancer and so the following recommendations are expert and consensus based:

• It is reasonable to assess tumour response with CT or MRI, in addition to clinical examination and relevant blood tests, after every three cycles of therapy.
• In patients with locally advanced rectal cancer who receive preoperative therapies, further imaging with CT or MRI should be done 4-6 weeks after neoadjuvant chemoradiotherapy.

Follow-up

The imaging panel endorses the Program in Evidence-based Care (PEBC) Gastrointestinal Cancer Disease Site Group's (DSG's) recommendations for follow-up every six months for three years post-operation and annually thereafter for two years. The recommendations from this guideline are as follows:

• In patients who are at high risk of relapse (stages IIb and III disease) and who are fit and willing to undergo investigations and treatment:
  • Clinical assessment is recommended when symptoms occur or at least every six months for the first three years and yearly for at least five years.
  • During follow-up, patients may have blood carcinoembryonic antigen, chest x-rays, and liver ultrasound.
  • When recurrences of disease are detected, patients should be assessed by a multi-disciplinary oncology team including surgical, radiation, and medical oncologists to determine the best treatment options.
• In patients at high risk of relapse but who have co-morbidities that may interfere with prescribed tests or potential treatment for recurrence, or who are unwilling to undergo prescribed tests or potential treatment for recurrence:
  • Clinical assessments yearly or for symptoms suggestive of relapse.
• For patients at lower risk of recurrence (stages I and Ia) or those with co-morbidities impairing future surgery, only visits yearly or when symptoms occur are recommended.
• In all patients with resectable colorectal cancer (stages I, II, and III), colonoscopy before or within six months of initial surgery.

The diagnostic imaging panel, based on expert opinion, has made one modification to the above. Since ultrasound is typically unable to detect local recurrences of colon or rectal cancer, and since the intent of follow-up is to identify resectable recurrent disease, and recognizing that we have endorsed CT or MRI versus ultrasound in the detection of liver metastases at presentation, we further recommend the following:

• In patients who are at high risk of relapse (stages IIb and III disease) and who are fit and willing to undergo investigations and treatment:
  • Abdominal and pelvic CT or MRI yearly for at least five years. This would remove the need for one of the bi-annual ultrasounds of the liver in the first three post-operative years and ultrasounds of the liver in post-operative years four and five.

Diagnosing Recurrence

Evidence from three case series does not indicate a difference between CT and MRI for diagnosing recurrence in patients with a clinical suspicion of disease recurrence. Therefore, either diagnostic test can be recommended.

None provided

The recommendations are supported by one practice guideline and 33 case series.

• Simunovic M, Stewart L, Zwaal C, Johnston M, Diagnostic Imaging Guidelines Panel. Cross-sectional imaging in colorectal cancer: recommendations report. Toronto (ON): Cancer Care Ontario (CCO); 2006 Apr 12. 19 p. [47 references]

Not applicable: The guideline was not adapted from another source.

2006 Apr 12

Program in Evidence-based Care - State/Local Government Agency [Non-U.S.]

The Program in Evidence-based Care (PEBC) is a Province of Ontario initiative sponsored by Cancer Care Ontario and the Ontario Ministry of Health and Long-Term Care.

Cancer Care Ontario
Ontario Ministry of Health and Long-Term Care

Diagnostic Imaging Guidelines Panel

Primary Authors: M. Simunovic; L. Stewart; C. Zwaal; M. Johnston

Prior to embarking on guideline development, the members disclosed information on potential conflict of interest. On reviewing that information, the panel found no areas of concern among the information provided by the panel members on the Program in Evidence-based Care's (PEBC's) standard conflict-of-interest form. Three panel members were investigators in trials of positron emission tomography (PET), but the panel decided that this was not in conflict with developing a guideline on computed tomography (CT), magnetic resonance imaging (MRI), and ultrasound. The lead author of this guideline report on imaging in colorectal cancer (Marko Simunovic) declared no conflicts of interest. The Program in Evidence-based Care is editorially independent of Cancer Care Ontario and the Ontario Ministry of Health and Long-term Care.

The following is available:

• Browman GP, Levine MN, Mohide EA, Hayward RSA, Pritchard KI, Gafni A, et al. The practice guidelines development cycle: a conceptual tool for practice guidelines development and implementation. J Clin Oncol 1995;13(2):502-12.

None available

This NGC summary was completed by ECRI on October 28, 2006. The information was verified by the guideline developer on November 24, 2006.