NICE UK issued evidence-based recommendations on microwave ablation for treating liver metastases in adults. This guidance replaces the previous NICE interventional procedures guidance on microwave ablation for the treatment of liver metastases. This guidance will be reviewed if there is new evidence or safety concerns.
Recommendations
Current evidence on microwave ablation for treating liver metastases raises no major safety concerns and the evidence on efficacy is adequate in terms of tumour ablation. Therefore this procedure may be used provided that standard arrangements are in place for clinical governance, consent and audit.
Patient selection should be carried out by a hepatobiliary cancer multidisciplinary team.
Further research would be useful for guiding selection of patients for this procedure. This should document the site and type of the primary tumour being treated, the intention of treatment (palliative or curative), imaging techniques used to assess the efficacy of the procedure, long term outcomes and survival.
Indications and current treatments
Liver metastases are a common manifestation of many primary cancers. The liver is the main site for metastases originating from colorectal or other gastrointestinal tract cancers.
The number, location and size of the metastases as well as the patient's general health and the site of the primary cancer all influence the choice of treatment for liver metastases. For a minority of patients, surgical resection with curative intent may be possible. While non surgical ablative techniques may be used with curative intent, for most patients treatment is palliative. Options for palliative treatment include systemic chemotherapy, external beam radiotherapy, thermal ablation techniques (such as radiofrequency or cryotherapy), arterial embolisation techniques, and selective internal radiation therapy. Multiple treatment modalities may be used for individual patients.
Thermal ablation techniques are normally used in patients for whom surgery would not be suitable, or for treating recurrence following surgical resection. They may also be used as an adjunct to hepatic resection, either to downstage the disease to facilitate liver resection or to ablate small volume disease in the liver remnant after resection.
The procedure
Microwave ablation aims to destroy tumour cells using heat, which creates localised areas of tissue necrosis with minimal damage to surrounding normal tissues.
The procedure can be done using local anaesthesia or with the patient under general anaesthesia, either percutaneously or during open or laparoscopic surgery. A probe is advanced into each targeted lesion under imaging guidance and the tumour is ablated by delivering high frequency microwave energy. Multiple pulses of energy may be delivered during a session, and multiple probes can be used to treat larger tumours.
A variety of different microwave devices can be used for this procedure.
About the efficacy and safety outcomes from the published literature that the NICE Committee considered as part of the evidence about this procedure, see the NICE guidance page.