International Study on Treatment of Patients With Metastatic Colorectal Liver Lesions Patients With IRE

Inclusion Criteria:

* Patients aged 18 years and over, able to provide informed consent and with histological confirmation of a diagnosis of colorectal cancer from primary tumour.
* Liver lesions demonstrating radiological characteristics (on magnetic resonance scan) of colorectal hepatic metastases without requirement for biopsy. In the setting of an intact liver, patients with up to four metastases ≤ 4cm in size are eligible for inclusion. In the setting of proposed resection plus ablation, up to two metastases ≤ 4cm in size. In the setting of recurrence after prior hepatectomy up to two metastases ≤ 4cm in size.
* Eastern Co-operative Oncology Group (ECOG) Score ≤ 2.
* Rockwood Frailty Score ≤ 3.
* Serum bilirubin \< 30 µmol/L.
* Serum creatinine \< 150 µmol/L.
* Up to two lung metastases (\< 2cm in size permitted at enrolment).
* Prior treatment with at least one course of systemic chemotherapy (± biologic agent) mandated. Chemotherapy protocol is not specified and is at clinician discretion.
* Primary rectal tumour can remain in situ treated with radiotherapy/chemoradiotherapy according to tumour board recommendations. Primary colonic tumour can remain in situ.
* No prior hepatic tumour ablation

Exclusion Criteria:

* Patients involved in other research studies.
* Inability to give informed consent.
* Patients who are pregnant.
* Accepted exclusions to IRE from consensus criteria including:
* Platelet count \< 50x109 U/L.
* International normalised ratio (INR) for blood clotting \> 1.7.
* Prior hepatic tumour ablation.

Cardiovascular fitness related exclusions:

* History of ventricular arrhythmia.
* Implanted pacemaker or defibrillator.
* Congestive cardiac failure NYHA Class ≥ 3.

Tumour-related exclusions:

* Tumour ≥ 4 cm in size.
* Advanced multi-site metastatic cancer (any of the following): peritoneal metastases (M1c), bone metastases, \> 2 lung metastases, all segment involvement multiple liver metastases.
* Jaundice (serum bilirubin \> 30 µmol/L).
* MDT/tumour recommends use of thermal ablation instead of IRE for any given lesion.