3D-CT Mammary Lymphography Facilitate the Endoscopic Sentinel Node Biopsy

In early breast cancer, the presence of metastasis in axillary lymph nodes is an important factor in prognosis and further treatment. However, axillary lymph node dissection causes many complications such as contracture of the shoulder joint, lymph edema, and paralysis of the upper extremities (Ernst, 2002). Convention holds that there is no need to dissect axillary lymph nodes for node-negative patients. To avoid unnecessary axillary lymph node dissection, sentinel node biopsy (SNB) has been performed (Veronesi, 1997; Schrenk, 2000). Sentinel node (SN) is defined as the first lymph node drained of lymph flow from the tumor (Schwartz, 2002; Kuehn, 2005). SNB can detect such metastases and provide information that may obviate the need for axillary lymph node dissection. The most commonly used methods to identify the SN are dye-staining (Giuliano, 1994; Borgstein, 1997) and radioisotope incorporation (Krag, 1993; Giuliano, 1994). Multidetector-row threedimensional computed tomography (3D-CT) mammary lymphography (LG) can be used to mark the precise location of the SN on the skin before the operation (Suga, 2003; Tangoku, 2004; Minato, 2004). The detailed relations between lymph nodes and lymph flow in the breast and the axilla can be clarified using 3D-CT LG (Yamashita, 2008, 2009). We have developed this 3D image processing system to depict more precise anatomical structure of mammary lymphovascular system. It enables us to perform systematic collection of axillary lymph nodes including SNs, and will decrease unnecessary lymph node dissection, even if the SNs have metastasized, and can decrease complications. Previously, we devised an endoscopic surgical procedure for breast diseases; video-assisted breast surgery (VABS) (Yamashita, 2006). VABS is a less invasive and esthetically a better operation for benign and malignant breast diseases In this study, we assessed the validity of 3D-CT LG in SNB of 186 patients, investigated the extent of metastasis style in 40 patients who were metastasis-positive based on the novel technique, and applied the technique to SNB using the dye-staining method and 3D-CT LG guidance.