Abstract P2-01-24: Sentinel lymph node biopsy using intraoperative indocyanine green fluorescence imaging navigated with preoperative computed tomography lymphography for early breast cancer
Authors: Abe Hajime , Yamazaki Keiichi , Ogawa Masao , Kawasaki Masayasu , Yoneda Kohri , Kameyama Masao 
Published: May 2015

Abstract
Background: Sentinel lymph nodes (SLN) biopsy has been established as a standard of care in the treatment of early breast cancer. The combination of the radioisotope and dye-staining methods is the most accurate way to identify sentinel lymph nodes. We had reported a novel technique of SLN identification using fluorescence imaging of indocyanine green (ICG) injection. However, if any lymphatic vessels are injured, further fluorescence navigation will be difficult because of ICG contamination in the surgical field in overweight or obese patients. In this study, a new diagnostic approach for imaging lymphatic drainage and identifying SLN using preoperative computed tomography-lymphography (CTLG) and an intraoperative ICG fluorescence method was investigated.
Patients and method: Between January 2013 and April 2014,105 breast cancer patients without clinical evidence of lymph node metastasis were treated. On the day before the operation, CTLG was performed using 64-row multidetector CT. We performed an intradermal injection in the periareolar area, using 4 ml of contrast agent with 0.5 ml of local anesthetic. The contrasted lymph flow and SLN were identified in reconstructed three-dimensional imaging. The SLN spot was indicated by CT laser light navigator system. During the operation, fluorescence images were obtained using the fluorescence imaging system, Photpdynamic Eye (pde-neo, Hamamatsu Photonics Co., Japan). After ICG was injected intradermally in to the periareolar skin, lymphatic drainage was observed with fluorescence images. SLN biopsy was performed by referring to the marker preoperatively placed on the CTLG. Moreover, we classified enhancement of SLN as "whole" and "partial" by CTLG with visual patterns, and examined the relation with SLN metastasis.
Results: The median age of the 105 patients was 63 (range 33 – 87) years old. CTLG and fluorescence imaging was safely performed in all patients. This method was visually easy to identify the location of SLN on the axillary skin even in obese patients. CTLG could visualize lymphatic flow and accurately identify SLN in 99 (94%) of 105 patients, whereas fluorescence imaging identified successfully lymphatic flow and SLN in all patients. Lymphatic flows of CTLG were completely consistent with those of fluorescence imaging. The number of SLN identified by CTLG was significantly lower than that by fluorescence imaging (1.1 vs. 1.6, p&lt;0.01). Fifteen patients (14%) were found to have lymph node metastases pathologically, and five of them had micrometastases of lymph node. In 6 patients without detected SLN by CTLG, only one patient had lymph node metastasis. In case of partial enhancement of SLN with CTLG, the rate of positive metastasis was significant higher compared to the cases of whole enhancement (p&lt;0.01).
Enhancement of SLNs by CTLG Metastasis(+)Metastasis(-)Whole459Partial1026Not identified15
Conclusion: This new navigation method of CTLG and fluorescence imaging revealed more easy and effective to detect SLN intraoperatively than fluorescence imaging alone. In addition, the information from CTLG may be helpful for the prediction of SLN metastasis.
Citation Format: Hajime Abe, Keiichi Yamazaki, Masao Ogawa, Masayasu Kawasaki, Kohri Yoneda, Masao Kameyama. Sentinel lymph node biopsy using intraoperative indocyanine green fluorescence imaging navigated with preoperative computed tomography lymphography for early breast cancer [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr P2-01-24.