The influence of FDG PET-CT on the detection of extrahepatic disease in patients being considered for resection of colorectal liver metastasis

Abstract

East Lancashire Hospitals NHS Trust, UKABSTRACT INTRODUCTION The aim of this study was to evaluate the influence of flurodeoxyglucose positron emission tomography computed tomography (FDG PET-CT), as an adjunct to conventional CT staging, in the detection of extrahepatic disease in patients with potentially resectable colorectal liver metastasis. METHODS Overall, 133 consecutive patients with colorectal liver metastases staged with CT and PET-CT referred to the East Lancashire regional hepatobiliary multidisciplinary team over a two-year period were included in this study. Abnormal findings on PET-CT were correlated with follow-up imaging and/or histology. All imaging was reviewed by specialist hepatobiliary radiologists for the presence/absence of extrahepatic disease. The influence of the PET-CT findings was categorised for each patient in relation to operability and other significant findings. RESULTS PET-CT had a major impact on staging of extra hepatic disease in 20% of patients, in comparison with the initial CT. Six per cent of patients were upstaged from operable CT findings to inoperable findings on PET-CT because of the discovery of inoperable occult extrahepatic disease. Five per cent had operable local regional nodal disease detected on PET-CT. A further 3% had premalignant colorectal lesions detected on PET-CT. Six per cent of patients were downstaged from indeterminate or suspected inoperable CT findings to operable findings on PET-CT. CONCLUSIONS The use of PET-CT in this setting may prevent futile operations, guide the resection of local regional nodal disease and downstage a number of patients thought to have extrahepatic disease on conventional imaging. This study has shown similar results to other recent studies and supports the use of PET-CT as a necessary staging modality in patients with potentially resectable colorectal liver metastases.

Are positron emission tomography-computed tomography (PET-CT) scans useful in preoperative assessment of patients with peritoneal disease before cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC)?

“…In our patient cohort, CT and/or MRI provided adequate information for decision-making in 63.7% (58 out of 91) of the cohort with PET-CT scans performed as adjuncts but PET-CT scans resulted in a change in management in 36.2% (33 out of 91) of our patients, mainly due to the avoidance of unnecessary laparotomies in 16.4% (15 out of 91) of the patients. This is similar to its effect when used for evaluating patients who are considered for liver resection of colorectal liver metastases [17,[25][26][27]. Importantly, all patients who had disease shown on PET-CT went on to have either histologically proven disease or progression of disease on follow-up scans, suggesting that PET-CT has a highly positive-predictive value in our cohort though the formal value was not calculated due to the lack of histopathology in a significant proportion of our patients.…”

Preoperative imaging for colorectal liver metastases: a nationwide population-based study

“…In the present study, an increase in the use of ceMRI in the Netherlands was observed, whereas use of 18F-FDG PET-CT decreased. These trends are probably the result of international publications 4,7,8,10,12,13,15,31,34 reporting the additional value of these imaging modalities.…”

“…The oncological advantage of preoperative 18 F‐FDG PET–CT to assess CRLM is doubtful, although this imaging method seems to have an advantage in identifying extrahepatic metastases of colorectal cancer. Some authors propose using 18 F‐FDG PET–CT during follow‐up to assess intrahepatic and extrahepatic metastases. Several European countries have preoperative imaging guidelines that contain advice regarding the use of both ceMRI and 18 F‐FDG PET–CT.…”

Predictors of early recurrence after resection of colorectal liver metastases

“…This group of patients is unlikely to benefit from LR as an isolated strategy and should be considered for pre-operative CT-PET and systemic chemotherapy. Using this approach, some patients with detectable FDG avid extra-hepatic disease may be spared from futile liver surgery [ 32 ]. PET/CT produces a fusion image combining conventional cross-sectional, anatomical imaging of CT with the biological, functional imaging of PET [ 33 ].…”