Protocol for the CoNoR Study: A prospective multi-step study of the potential added benefit of two novel assessment tools in colorectal liver metastases technical resectability decision-making

IntroductionLiver resection is the only curative treatment for colorectal liver metastases (CLM). Resectability decision-making is therefore a key determinant of outcomes. Wide variation has been demonstrated in resectability decision-making, despite the existence of criteria. This paper summarises a study protocol to evaluate the potential added value of two novel assessment tools in assessing CLM technical resectability: the Hepatica preoperative MR scan (MR-based volumetry, Couinaud segmentation, liver tissue characteristics and operative planning tool) and the LiMAx test (hepatic functional capacity).Methods and analysisThis study uses a systematic multistep approach, whereby three preparatory workstreams aid the design of the final international case-based scenario survey:Workstream 1: systematic literature review of published resectability criteria.Workstream 2: international hepatopancreatobiliary (HPB) interviews.Workstream 3: international HPB questionnaire.Workstream 4: international HPB case-based scenario survey.The primary outcome measures are change in resectability decision-making and change in planned operative strategy, resulting from the novel test results. Secondary outcome measures are variability in CLM resectability decision-making and opinions on the role for novel tools.Ethics and disseminationThe study protocol has been approved by a National Health Service Research Ethics Committee and registered with the Health Research Authority. Dissemination will be via international and national conferences. Manuscripts will be published.Registration detailsThe CoNoR Study is registered with ClinicalTrials.gov (registration number NCT04270851). The systematic review is registered on the PROSPERO database (registration number CRD42019136748).