SLN in Colon Cancer Using a Multimodal Tracer

Rationale: Lymph node status is the most important factor in the selection of patients for adjuvant chemotherapy after surgical treatment of primary colorectal carcinoma. Up to 30% stage I/II patients with negative lymph node involvement will develop distant metastases and eventually die from colorectal carcinoma (CRC). Better detection and pathologic staging of the lymph nodes could contribute to a better survival of colon cancer patients. This sentinel lymph node (SLN) procedure aims to identify the first draining lymph node(s) from the primary tumour, which have the highest risk of harbouring metastases. These SLNs can be pathological analysed with several more sensitive histopathologic techniques like immunohistochemical staining (IHC). Objective: Aim of this study is to investigate if the combination of a radioactive and fluorescent tracer can increase the sensitivity and specificity of the sentinel lymph node mapping (SLNM) technique in colon cancer by utilizing the radioactive component for preoperative imaging (PET/CT) of the SLNs and the near infrared (NIR) fluorescence component for guidance to the SLNs during surgery. Study design: Single centre pilot study Study population: Ten patients with colon cancer (colon ascendens, colon transversum, colon descendens, sigmoid) stage Tis-T1-T2-T3, scheduled for laparoscopic surgical resection of the tumour. Intervention (if applicable): The present study will be performed with the radioactive tracer 89Zr-Nanocoll and fluorescent tracer Indocyanine Green (ICG). A colonoscopy will be performed to inject the radioactive tracer 48 hrs before surgery. After injection, patients will undergo the first PET/CT scan. A second PET/CT scan will be performed ± 24 hrs after tracer injection and a third scan just before the surgical procedure; ± 48 hrs after tracer administration. During the surgical procedure ICG diluted in saline and human albumin will be injected at the base of the tumour by colonoscopy. The PET/CT images