Clinical case of fusion-guided-contrast-enhanced ultrasonography to mark missing colorectal metastases

Abstract

Introduction: Modern chemotherapy achieves the reduction in size of colorectal cancer liver metastases (CRLM) to such extent that they may disappear from radiological imaging. Fusion-guided-contrast-enhanced Ultrasonography marking consists in the fusion of real-time US and computed tomography/magnetic resonance (CT/MR) images. This technique allows a correct identification of missing metastases prior to surgery and the placement of fiducial markers, making easier its identification and resection during the surgical procedure. Case presentation: A 71-year-old Caucasian man was admitted in our center with abdominal pain. CT scan was performed, showing large bowel obstruction secondary to a tumor with 3 liver metastases. An extended right hemicolectomy was performed. The pathology report showed moderately differentiated adenocarcinoma pT4N0. After the surgical recovery was decided to proceed with chemotherapy, 10 courses of FOLFOX. After the treatment a CT scan, PETCT and MRI were performed, showing 2 of the 3 lesions. Prior to the liver surgery a gold fiducial marker was placed under Fusion-guided-contrast-enhanced Ultrasonography, were the Missing Metastasis was placed. During surgery we could easily identify the Missing Metastasis marked, performing 3 non-anatomical resections. The pathology report showed complete pathological response with fibrosis, with no viable tumor cells in the three lesions, being the lesions not marked with coil calcified. Conclusion: The placement of fiducial markers by fusion USS-CT/MRI are an important tool to assist the surgeon identifying the location liver metastases when disappear after chemotherapy. The true impact of this technique to control liver progression has to be still investigated.