Elsevier

Clinical Radiology

Volume 66, Issue 12, December 2011, Pages 1167-1174
Clinical Radiology

Clinical impact of FDG PET-CT in patients with potentially operable metastatic colorectal cancer

https://doi.org/10.1016/j.crad.2011.07.046Get rights and content

Aim

To assess the clinical impact of 2-[18F]-fluoro-2-deoxy-d-glucose (FDG) positron-emission tomography–computed tomography (PET-CT) in patients with potentially resectable metastatic colorectal cancer.

Materials and methods

One hundred and two patients with potentially resectable metastatic colorectal cancer underwent FDG PET-CT in addition to conventional imaging over an 18-month period. The findings were compared to conventional imaging, with histological or clinico-radiological validation. The impact on subsequent management was evaluated using information from clinico-radiological databases.

Results

Of 102 patients (mean age 67 years, range 27–85 years), 94 had liver, five had isolated lung, and three had limited peritoneal metastases. In 31 patients (30%) PET-CT had a major impact on subsequent management, by correctly clarifying indeterminate lesions on conventional imaging as inoperable metastatic disease in 16 patients, detecting previously unsuspected metastatic disease in nine patients, identifying occult second primary tumours in three patients, and correctly down-staging three patients. PET-CT had a minor impact in 12 patients (12%), no impact in 49 cases (48%), and a potentially negative impact in 10 cases (10%). Following PET-CT, 36 (35%) patients were no longer considered for surgery. Of those remaining operative 45 of 66 (68%) underwent potentially curative metastatic surgery. In this cohort PET-CT saved 16 futile laparotomies.

Conclusion

FDG PET-CT has a valuable role in selected patients with metastatic colorectal cancer by improving staging accuracy and characterizing indeterminate lesions and helps triage patients to the appropriate treatment.

Introduction

Colorectal cancer (CRC) remains one of the most common malignancies in the UK, accounting for approximately 21,000 cases annually in men and 17,000 in women.1, 2, 3 Long-term patient outcome is heavily influenced by the initial stage of disease. Between 25–30% of patients have hepatic metastases at presentation, and recurrent disease is seen in up to 30% of patients within 2 years of initial resection, which in the majority manifests as liver metastases.4, 5 Surgical resection of limited metastatic disease with curative intent is a well-established treatment strategy, with recent meta-analyses demonstrating favourable long-term outcomes.6, 7, 8, 9, 10, 11 At least 17% of patients have a ≥10 year disease-free survival after liver metastatectomy, with a 5 year survival of 26–50%.6, 7, 8, 9, 10 Five-year survival of up to 64% has also been demonstrated following resection of pulmonary metastases.11 Appropriate patient selection is crucial; historically, up to 50% of patients with disease apparently limited to the liver on conventional imaging had inoperable findings at laparotomy.12 The prevalence of unexpected extra-hepatic disease at liver surgery is now around 5–10% largely due to improvements in cross-sectional imaging technology over the past couple of decades. Although the presence of extrahepatic disease has been shown to increase mortality and has traditionally been taken as a contraindication to resection of liver metastases,13 this no longer represents an absolute contraindication to surgery, but necessitates a wider operative field or second operation, if technically feasible, to allow a truly curative surgical resection.6, 14 Five-year survival of 29% following complete resection of both simultaneous intra- and extrahepatic metastases has been reported.15

Over the past decade 2-[18F]-fluoro-2-deoxy-d-glucose (FDG) positron-emission tomography–computed tomography (PET-CT) has been established as a major component in the management of cancer patients.16 The optimal role of FDG PET-CT in patients with CRC has not yet been fully defined. In 2004 the National Institute for Health and Clinical Excellence (NICE) included a review of the available literature in their document Improving outcomes in colorectal cancer, suggesting that PET-CT was most useful in the detection of disease recurrence.17 One of the more compelling indications for FDG PET-CT is in CRC patients being considered for metastatectomy, in order to avoid inappropriate major surgery in patients with undetected nodal or distant metastatic disease. The aim of the present study was to analyse the clinical impact on patient management of introducing FDG PET-CT into the preoperative work-up of patients with potentially resectable metastatic CRC in a large-volume tertiary-referral centre.

Section snippets

Patients

Data were collected retrospectively over an 18-month period (November 2007 to March 2009). Following consultation with the Chairman of our institutional ethics committee, full ethics review board submission and approval was not required for the study. A search was performed on the institutional radiology information system (CRIS™, Healthcare Software Systems, Banbury, UK). Consecutive data collection identified 112 patients with histologically proven colorectal adenocarcinoma who underwent FDG

Results

A total of 102 patients remained after exclusions. The mean patient age was 67 years (range 27–85 years) with a male to female ratio of 4:3. The group consisted of 94 (93%) patients with known colorectal liver metastases, five (5%) with isolated lung metastases, and three (3%) with intra-abdominal deposits all under consideration for curative resection. Within the study group, 17 (17%) patients had undergone prior surgical resection for either liver (n = 14), lung (n = 1), or both liver and lung (n =

Discussion

The present study investigated the role of PET-CT in the preoperative work-up of patients with metastatic CRC under consideration for curative resection. The majority of patients had liver metastases (93%), with lung and peritoneal deposits accounting for the remainder. PET-CT was concordant with conventional imaging findings in 65 (64%) patients. This concurs with other studies in similar patient groups with concordance rates between PET-CT and conventional imaging most commonly quoted between

References (47)

  • J. Scheele et al.

    Resection of colorectal liver metastases

    World J Surg

    (1995)
  • P.E. Valk et al.

    Whole-body PET imaging with F-18 fluorodeoxyglucose in management of recurrent colorectal cancer

    Arch Surg

    (1999)
  • J.S. Tomlinson et al.

    Actual 10-year survival after resection of colorectal liver metastases defines cure

    J Clin Oncol

    (2007)
  • J.M. McLoughlin et al.

    Resection of colorectal liver metastases: current perspectives

    Cancer Control

    (2006)
  • Y. Fong et al.

    Clinical score for predicting recurrence after hepatic resection for metastatic colorectal cancer: analysis of 1001 consecutive cases

    Ann Surg

    (1999)
  • Society for Surgery of the Alimentary Tract. Guidelines for surgery for hepatic colorectal metastases 2004. Available...
  • K.S. Hughes et al.

    Resection of the liver for colorectal carcinoma metastases: a multi-institutional study of patterns of recurrence

    Surgery

    (1986)
  • T.M. Pawlik et al.

    Expanding criteria for resectability of colorectal liver metastases

    Oncologist

    (2008)
  • D. Elias et al.

    Extrahepatic disease does not contraindicate hepatectomy for colorectal liver metastases

    Br J Surg

    (2003)
  • B.E. Hilner et al.

    Impact of positron emission tomography/computed tomography and positron emission tomography (PET) alone on expected management of patients in cancer; initial results from the national oncologic PET registry

    J Clin Oncol

    (2008)
  • Improving outcomes in colorectal cancer. London: National Institute for Health and Clinical Excellence, 2004. Available...
  • A.G. Heriot et al.

    Does positron emission tomography change management in primary rectal cancer: a prospective assessment

    Dis Colon Rectum

    (2004)
  • T.J. Ruers et al.

    Value of positron emission tomography with [F-18]fluorodeoxyglucose in patients with colorectal liver metastases: a prospective study

    J Clin Oncol

    (2002)
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