Intraoperative detection of sentinel lymph nodes in breast cancer patients using ultrasonography-guided direct indocyanine green dye-marking by real-time virtual sonography constructed with three-dimensional computed tomography-lymphography

PurposeThis study aims to determine the utility of ultrasonography (US)-guided direct dye-marking of sentinel lymph nodes (SLNs) by real-time virtual sonography (RVS) constructed with three-dimensional (3D) computed tomography (CT)-lymphography (LG).Patients and methodsWe identified SLNs in 258 clinically node-negative breast cancer patients using an RVS system to display in real time a virtual multiplanar reconstruction CT image obtained from CT volume data corresponding to the same cross-sectional image from US. CT volume data were obtained using our original 3D CT-LG, which accurately detects SLNs in breast cancer. We then perform US-guided dye-marking close to SLNs using indocyanine green (ICG). Subsequently, indigo carmine blue dye was injected into the subareolar and peritumoral areas around each primary tumor. All patients underwent SLN biopsy and SLN metastases were examined pathologically.ResultsIn all 258 patients, we were able to detect the same SLNs visualized on 3D CT-LG, using the RVS system. We detected ICG close to SLNs in 257 of 258 patients (99.6%) during SLN biopsy. In 25 patients (9%), we failed to follow the blue lymphatic route stained by indigo carmine and SLNs were not stained by indigo carmine, but easily detected SLNs by ICG marking.ConclusionUS-guided direct ICG dye-marking of SLNs using this RVS system seems useful for the detection of SLNs, allowing easy detection of SLNs even when the stained lymphatic route is not followed.