Magnetic Sentinel Lymph Node Mapping in Upper Gastro-Intestinal Cancer: A Feasibility Clinical Investigation

Inclusion Criteria: * Subject is capable of understanding and has provided written informed consent. * Subject over 18 years of age and is fit to complete the study in the opinion of the investigator. * Subject with a previously untreated histopathology confirmed diagnosis of gastric, gastric-oesophageal junction, oesophageal cancer and at the time of enrolment is expected to undergo curative-intent surgery. * Females of childbearing potential must be willing to use methods of contraception as deemed adequate by the Investigator to be eligible for, and continue participation in, the study. * In the opinion of the Investigator, the subject can complete the study in compliance with the Investigational Plan and is able to comply with the requirements of the Investigational Plan. * Subjects with an Eastern Cooperative Oncology Group (ECOG) performance status of Grade 0-2. * Additional tumour specific inclusion criteria for subjects in expansion cohorts as directed by the Sponsor. Exclusion Criteria: * Subject has distant metastasis as detected on CT, PET, ultrasound guided fine needle aspiration (FNA), or cytology prior to enrolment. * Subject started neoadjuvant therapy before informed consent, or prior to FerroTrace® administration. * Subject has received a Feraheme® (ferumoxytol) injection within the past 180 days. * Subject has a known or suspected history of allergies, hypersensitivity, or intolerances as follows: 1. Iron compounds 2. Polyacrylamide 3. Polyethylene glycol (PEG) or has had an anaphylactic reaction to the Pfizer or Moderna COVID vaccines 4. Iodine compounds 5. Known or suspected hypersensitivity to FerroTrace®, or to any ingredients of FerroTrace®. * Subject known to have haemochromatosis. * Subjects with other known iron metabolism disorder(s) if the Investigator determines the subject is at a higher risk of iron toxicity. * Subjects who at the time of enrolment are pregnant or lactating, or from the time of enrolment through to 14 days after injection of the study dose are trying to become pregnant, planning to impregnate a partner, or planning to donate sperm. * Subject has one or more absolute contraindications to MRI scanning as per Investigator judgement. * Subjects with an estimated glomerular filtration rate (eGFR) of \< 30 mL/min/1.73m2. * Subject has inability or unwillingness to comply with all follow-ups through to the end of the study, and/or unwilling to allow review of medical records in accordance with local regulatory requirements at time of consent. * Investigator determines that the subject is not suitable for study participation for any other reason. * Subject received an investigational product (IP) within 30 days of FerroTrace® administration unless agreed by the sponsor. * Subjects have hyperthyroidism or benign thyroid nodules