Background In patients with colorectal liver metastases (CRLM) preoperative imaging may include contrast‐enhanced (ce) MRI and [18F]fluorodeoxyglucose (18F‐FDG) PET–CT. This study assessed trends and variation between hospitals and oncological networks in the use of preoperative imaging in the Netherlands. Methods Data for all patients who underwent liver resection for CRLM in the Netherlands between 2014 and 2018 were retrieved from a nationwide auditing database. Multivariable logistic regression analysis was used to assess use of ceMRI, 18F‐FDG PET–CT and combined ceMRI and 18F‐FDG PET–CT, and trends in preoperative imaging and hospital and oncological network variation. Results A total of 4510 patients were included, of whom 1562 had ceMRI, 872 had 18F‐FDG PET–CT, and 1293 had combined ceMRI and 18F‐FDG PET–CT. Use of ceMRI increased over time (from 9·6 to 26·2 per cent; P < 0·001), use of 18F‐FDG PET–CT decreased (from 28·6 to 6·0 per cent; P < 0·001), and use of both ceMRI and 18F‐FDG PET–CT 16·9 per cent) remained stable. Unadjusted variation in the use of ceMRI, 18F‐FDG PET–CT, and combined ceMRI and 18F‐FDG PET–CT ranged from 5·6 to 100 per cent between hospitals. After case‐mix correction, hospital and oncological network variation was found for all imaging modalities. Discussion Significant variation exists concerning the use of preoperative imaging for CRLM between hospitals and oncological networks in the Netherlands. The use of MRI is increasing, whereas that of 18F‐FDG PET–CT is decreasing.
