Sentinel Lymph Node Mapping and Analysis in Colon Cancer Using Indocyanine Green Dye
Condition: Colon Cancer
MeSH terms: Colonic Neoplasms
Study type: Interventional

Summary: 
      Approximately 20-30 % of colon cancer patients who have no metastasis in lymph nodes after
      definitive colectomy have recurrence with distant metastasis. These recurrences could be due
      to missed occult tumor cells or micrometastasis. Detailed examination of all lymph nodes is
      expensive and time consuming. Sentinel lymph node mapping using Indocyanine green dye helps
      in identifying the lymph nodes which are most likely to harbour metastasis. These sentinel
      lymph nodes can be subsequently subjected to detailed pathologic examination and
      immunohistochemistry which increases the likelihood of identifying micrometastasis and occult
      tumor cells. Patients found to harbour such metastasis can be treated with additional
      chemotherapy after surgery. The aim of the study is to examine the feasibility of sentinel
      lymph node mapping using Indocyanine green dye in colon cancer and evaluate the upstaging
      rate in post-operative colon cancer patients who don't have metastatic lymph nodes on routine
      histopathology.
    

Detailed description: 
      All patients of colon cancer fulfilling the inclusion criteria and excluding the patients
      according to the exclusion criteria will undergo standard laparoscopic/open colectomy.

      Indocyanine green dye is injected around the tumor in subserosal location for open surgeries
      and submucosally after on-table colonoscopy for laparoscopic surgeries and followed with
      near-infrared scope. Patients will undergo intra-operative on-table colonoscopy after
      induction of anesthesia. All sentinel nodes will be marked with clips/sutures for
      identification by the pathologist post-operatively. Any aberrant lymph nodes identified
      outside the planned resection margins will be excised, marked with the position of excision
      and sent separately from the gross specimen. After this the surgeon will proceed with the
      surgery including vascular ligation and resection of mesocolon.

      After surgery, all the lymph nodes identified in the specimen including the tagged sentinel
      lymph nodes will be examined using standard Hematoxylin and eosin staining. If all the lymph
      nodes are negative for metastasis, the sentinel lymph nodes will undergo additional stepwise
      sections and immunohistochemistry for pancytokeratin.
    

Intervention name(s): sentinel lymph node mapping
Intervention type(s): Procedure
Intervention description(s): Through on-table colonoscopy indocyanine green solution will be injected in the submucosa at 2-4 points around the tumor for laparoscopic surgeries. Dye will be injected in the subserosa at 2-4 points for open surgeries. Lymphatic flow from the tumor will be mapped in real time with near-infrared fluorescence imaging scope and sentinel lymph nodes will be identified.
Intervention model: Single Group Assignment
Intervention model description: Sentinel lymph node mapping: 25 mg of Indocyanine green dye diluted in 1 ml of 20% Albumin solution and 9 ml of 0.9% Normal saline solution will be used. Injections (0.5-1 ml) will be given in the submucosa or subserosa at 2-4 points around the tumor proximally and distally. Lymphatic flow will be followed after injection in real time with Near-infrared fluorescence imaging scope until sentinel lymph nodes will be identified.
Masking: None (Open Label)
Primary purpose: Diagnostic
Keywords: Sentinel lymph node; Indocyanine green