RESOLUTE Trial Aims to Investigate the Value of Adding Local Ablative Treatment to Standard Systemic Treatment for Unresectable Oligometastatic Colorectal Cancer

Inclusion Criteria: * Metastatic colorectal adenocarcinoma that is not amenable to potentially oncological curative surgery alone. * Primary tumour must be controlled if the primary is intact, with no evidence of progression at primary site prior to study entry * Imaging demonstrating ongoing treatment benefit (partial response or stable disease as per RECIST criteria) after 3-4 months of standard first-line systemic treatment. * At least one metastatic lesion detected on CT +/- FDG-PET scan prior to first line systemic treatment AND on screening FDG-PET and CT scans, meeting the following criteria: 1. max of 3 lesions per organ except for the liver and lung 2. max of 5 lesions in the lung 3. no limitation to the number of liver lesions provided they are all amenable to LAT 4. max of 3 involved organs including a lymph node station 5. only one lymph node station involvement is allowed 6. for patients with liver metastases, a quadruple phase contrast enhanced CT or MRI liver is required to fully stage the liver; this can be performed prior to or within 4 weeks of commencing first line systemic treatment 7. staging FDG-PET scan is encouraged and can be performed prior to or within 4 weeks of commencing first line systemic treatment * All lesions can be safely treated by LAT as determined by multidisciplinary team meeting. Exclusion Criteria: * Deficient mismatch repair (dMMR) or microsatellite instability-high (MSI-high) tumour * BRAFV600E mutated tumour * Concurrent or previous other malignancy within 2 years of study entry, except curatively treated basal or squamous cell skin cancer, prostate intraepithelial neoplasm, carcinoma in-situ of the cervix, Bowen's disease or prostate cancer with a Gleason score ≤6. * Presence of brain, peritoneal, omental or ovarian metastases * Malignant pleural effusion or ascites.