A meta-analysis exploring the role of PET and PET-CT in the management of potentially resectable colorectal cancer liver metastases.

BACKGROUND

Positron emission tomography (PET), alone or combined with computed tomography (CT), potentially enhances detection of occult metastatic colorectal cancer.

METHODS

We compared the impact of PET/PET-CT with conventional imaging, versus conventional imaging alone, in patients with potentially resectable colorectal cancer liver metastases. MEDLINE, EMBASE, and CENTRAL were searched for studies investigating PET/PET-CT to determine resectability. Outcomes included overall (OS), disease-free survival (DFS), change in surgical management, and futile laparotomy. Evidence quality was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) framework. A pre-specified protocol was registered in PROSPERO.

RESULTS

Of 4034 articles, two randomized trials (n = 554), and 11 non-randomized studies (n = 2251) were included. PET/PET-CT did not improve OS (hazard ratio [HR] 0.94, 95% CI 0.69-1.26, moderate quality) or DFS (HR 1.01, 95% CI 0.82-1.26, moderate quality). In the two trials, PET/PET-CT changed surgical management in 8% of cases (95% CI 5-11%, high quality), and did not significantly reduce futile laparotomies (risk ratio 0.59, 95% CI 0.24-1.47, low quality). Among non-randomized studies, PET/PET-CT changed surgical management in 20% of cases (95% CI 17-22%, very low quality) and reduced futile laparotomies (odds ratio 0.51, 95% CI 0.32-0.81, very low quality).

CONCLUSIONS

Moderate-quality evidence suggests that preoperative PET/PET-CT does not improve OS or DFS in patients with colorectal cancer liver metastases. These results do not support routine use of PET/PET-CT in patients with potentially resectable disease. The main limitation of this study was the lack of randomized studies.