3-dimensional computed tomography lymphography-guided identification of sentinel lymph nodes in breast cancer patients using subcutaneous injection of nonionic contrast medium - A clinical trial

Objective: Simple and reliable identification methods for sentinel lymph nodes (SLNs) which do not use radioisotope are essential for early breast cancer patients in community hospitals in Japan. The purpose of this paper is to demonstrate the feasibility and efficacy of computed tomography (CT) lymphography for SLN detection. Methods: The study included 15 cases with T 1 or T2 breast cancer. After subcutaneous injection of 1 mL of iopamidol in 1 subareolar area of the affected breast, CT scanning was carried out and 3-dimensional (3D) CT images were created. SLNs predicted from images and CT values were assessed as to whether they were identical to those identified by the dye method. Results: An enhanced lymph vessel draining into SLN was demonstrated in 11 cases (73%) and an enhanced SLN in 10 cases (67%). 3D images clearly revealed the anatomic relationship between lymph vessels, SLN, and the surrounding structures. In addition, SLN could be predicted by the change of CT value in the time-course in another case. In total, SLN in 13 cases (87%) could be predicted. All SLNs suggested from CT lymphography were identified by the dye method. No significant adverse effect was noted in any case. Conclusions: The present clinical trial indicated that subcutaneous injection of nonionic contrast medium with CT scanning seems to be a promising method for the demonstration of a draining lymph vessel and SLN. The CT value time-course may also provide some important information. Further trials will be needed for the successful establishment of this CT lymphography-guided method for SLN identification.