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[Local ablation of colorectal liver metastases--a systematic review].

BACKGROUND
Local ablation is a term used for tumour destruction in situ by exposing tumours for heat, cold or chemical substances. A systematic review of long-term survival after local ablation of non-resectable colorectal liver metastases is presented.


MATERIAL AND METHODS
A systematic search was performed for studies where one or more of the following modalities were used to treat colorectal liver metastases: radiofrequency-, cryo-, laser- or microwave ablation, ethanol injection and high-intensity focused ultrasound. Studies that reported survival and had at least 20 patients with a median follow-up time of two years or more were considered for inclusion.


RESULTS
Eight non-randomized studies with a total of 669 patients were included. Radiofrequency ablation was used in four studies, cryo ablation in three and laser ablation in one. Median follow-up and median survival varied from 24 to 35 months. Short-term survival did not differ discernibly between the modalities. Five-year survival was reported in three studies and varied from 7% to 30%.


DISCUSSION
Data on long-term survival after local ablation of non-resectable colorectal liver metastases are scarce. Long-term survival after local ablation of non-resectable colorectal liver metastases is shorter than that in patients with resectable colorectal liver metastases that have been resected.