Abstract PD2-06: Preoperative diagnosis of sentinel lymph node metastasis using computed tomography lymphography for early breast cancer patients
Authors: Abe H , Teramoto A , Tanaka M , Yamasaki K , Yoneda K 
Published: February 2018

Abstract
Background: Sentinel lymph nodes (SLN) biopsy has been established as a standard of care in the treatment of early breast cancer. This technique represents a minimally invasive, highly accurate method of axillary staging and is an alternative to conventional axillary lymph node dissection. However, an indication of SLN navigation to metastatic disease may lead to misdiagnosis for staging. Recently, SLN identification using computed tomography lymphography (CTLG) has been reported in Japan. This study investigated the value of CTLG for preoperative prediction of SLN status in early breast cancer patients.
Patients and method: Between January 2013 and August 2016, 350 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 helical CT scanner. Patients were placed in a supine position with their arms positioned in a cranial direction with CT guidelineattached to the skin at the axilla. We performed an intradermal injection in the periareolar area, using 4 ml of iopamidolwith 1 ml of local anesthetic. The contrasted lymph route and SLN were identified in reconstructed three-dimensional imaging. The SLN spot was indicated by CT laser light navigator system. We established typical pattern of the lymphography: stain defect of SLN, stagnation of lymphatic route for preoperative diagnosis of metastatic SLN. SLN biopsy was performed using the fluorescence imaging system, Photpdynamic Eye (pde-neo, Hamamatsu Photonics Co., Japan) referring to the point by axillary compression technique by plastic device. Intraoperative pathological analysis of SLN was examined, and an axillary lymph node dissection was performed in patients with SLN metastasis pathologically.
Results: The median age of the 350 patients was 59 (range 28 – 90) years old. One patient was male and others were female. CTLG were safely performed in all patients. CTLG could visualize lymphatic route and accurately identify SLN in 336 (96.0 %) and 343 (98.0 %) cases, respectively. Lymphatic routes of CTLG were completely consistent with those of fluorescence imaging. The mean number of SLN identified by CTLG was 1.1. Fifty of 350 patients had metastatic SLN pathologically, and 11 of them had micrometastases of SLNs. The accuracy for metastatic diagnosis of SLN using CTLG without micrometastasis was 84.1 %, sensitivity was 82.1 % and specificity was 84.3 %. The positive predictive value was 40.5 % and negative predictive value was 97.3 %. There were no complications associated with SLN identification.
Conclusion: CTLG in SLN biopsy has some advantages in that this method is simple and quite useful for obtaining accurate anatomic images of the SLN, lymph vessels, and tumor. CTLG could select the candidate with truly node negative cases in early breast cancer patients, because it predicts lymph node metastasis preoperatively from natural status of the lymphographic image.
Citation Format: Abe H, Teramoto A, Tanaka M, Yamasaki K, Yoneda K. Preoperative diagnosis of sentinel lymph node metastasis using computed tomography lymphography for early breast cancer patients [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr PD2-06.