FDG PET-CT imaging for pre operative staging in patients with colorectal cancer

  • Protocol
  • Diagnostic

Authors


Abstract

This is the protocol for a review and there is no abstract. The objectives are as follows:

Primary colorectal cancer (replacement test)

The primary objective is to determine the diagnostic accuracy of integrated FDG PET-CTas a replacement test to conventional imaging for the pre-operative staging of primary colorectal cancer. The comparisons of interest are:

1. PET-CT versus routinely used imaging modalities (e.g. CT chest/abdomen pelvis combined with pelvic MRI imaging) for pre operative staging of primary rectal cancer.

2. PET-CT versus CT alone for pre-operative staging of primary colonic cancer.

Recurrent colorectal cancer (add-on test)

The primary objective is to determine the diagnostic accuracy of integrated FDG PET-CT as an add-on test for conventional imaging for the pre-operative staging of recurrent colorectal cancer. The comparisons of interest are:

1. PET-CT combined with pelvic MRI imaging versus routinely used imaging modalities (e.g. CT chest/abdomen/pelvis + MRI pelvis) for staging of recurrent rectal cancer

2. PET-CT plus or minus MRI imaging versus routinely used imaging modalities (e.g. CT chest/abdomen/pelvis + or - MRI pelvis) for staging of patients with recurrent colon cancer

Metastatic colorectal cancer (add-on)

The primary objective is to determine the diagnostic accuracy of integrated FDG PET-CT as a replacement test for conventional imaging for the pre-operative staging of recurrent colorectal cancer. The comparisons of interest are:

1. PET-CT versus clinical follow-up including standard imaging as a replacement test for the detection of extra-hepatic and intra-hepatic lesions.

We will assess adverse effects reported in the included studies.

Several potential sources of heterogeneity have been identified in other (non-Cochrane) systematic reviews and meta-analyses of diagnostic imaging techniques in colorectal cancer (Bipat 2004; Bipat 2005; Halligan 2005; Huebner 2000; Purkayastha 2006; Wiering 2005). These were considered by the clinical authors of this review who identified the factors most likely to affect diagnostic accuracy in studies of FDG PET-CT.

We will investigate the following potential sources of heterogeneity, using subgroup analysis where possible: academic (e.g. university hospital) versus non-academic setting; indication known or suspected; study conducted up to 2005 and post-2005 (reflecting differences in PET-CT technology); blinding of index and reference standard tests and their interpretation (or not). Heterogeniety arising from different reference standards will also be explored.

Heterogeneity in the statistical analysis will initially be assessed graphically and where possible using meta-regression (see Investigations of heterogeneity, below).

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