Image-guided Lymphadanectomy in AMIGO

Only the superficial lymph nodes are accessible to physical examination, and assessment of deeper nodes, such as those in the abdomen, requires radiological imaging. As a result, abdominal CT and PET scanning of patients with a history of malignancy or concerns for a new diagnosis of cancer is an important diagnostic test. As well as looking for distant metastasis, the images are carefully assessed for evidence of intra-abdominal lymphadenopathy, which can be a marker of new or recurrent cancer. If such nodes are identified, they often require a biopsy for further evaluation.

The lymph nodes located in the abdomen or the retroperitoneum are not easily accessible for percutaneous biopsy, often requiring an abdominal exploration which can be done either laparoscopically or via laparotomy. The laparoscopic approach represents a better approach that is associated with reduced surgical risks and complications as well as a quicker recover. In fact in many cases, the laparoscopic approach can be done as a day surgery procedure.

Although non-invasive imaging technologies such as computed tomography (CT) scanning, magnetic resonance imaging (MRI), and positron emission tomography (PET) scanning can be useful in the diagnosis of lymphadenopathy, they often provide an estimate of the location of the nodes, and exact localization of the lymph node of interest can be challenging. The surgeons rely on anatomical landmarks which can be distorted during laparoscopy and to help reduce the rate of false negative lymph node biopsy, the surgeons often perform intra-operative histological assessment of the lymph nodes (Frozen Section) which can be time consuming and in itself associated with diagnostic errors. The uncertainty about the exact location of the node of interest often leads to extensive surgical dissection, biopsy of multiple nodes, and sometimes repeat surgery. During the dissection, care must be taken to avoid injury to the neighboring structures, such as blood vessels, nerves or adjacent organs. In cases, where an intra-operative dissection occurs, or lymph nodes can not be identified, the laparoscopic surgery is converted to open surgery.

Using the unique capabilities of the AMIGO suite, investigators aim to test intra-operative image guidance to help them identify diseased intra-abdominal lymph nodes, allowing for more precise and safer surgeries. The improved accuracy will allow investigators to perform surgeries with minimal dissection and reduced complications while improving biopsy rates and enhancing ability to accurately stage intra-abdominal malignancies.