The sample analyzed (n=39) consisted of two groups of patients: patients who underwent ALND (n=22) and patients who underwent SLNB (n=17). The mean age and BMI were similar between the groups, but there was a significant difference in the number of lymph nodes removed (P<0.01) and in the number of positive lymph nodes, evident only in the ALND samples, as shown in Table 1. The patients with positive sentinel lymph nodes were sequentially submitted to ALND and excluded from the study.
A total of 54.5% (n=12) of patients who underwent ALND and 35.3% (n=6) of patients who underwent SLNB had surgery on the right breast. Regarding the type of surgery, conservative and partial surgeries were predominant in the SLNB group, while in the ALND group, ~50% of the patients underwent radical mastectomies, as shown in Table 2. Only 23.5% (n=4) underwent immediate breast reconstruction, and these patients were from the SLNB group.
The lymph ducts were more evident in the early LS images, which were acquired within up to 40 minutes (Dynamic and Static 1, 2), with the arm and axilla being the most frequent sites reached by the lymphatic fluid in both groups analyzed (ALND × SLNB), with no significant difference. The delayed LS images at 90 minutes (WBS) identified significant differences between the ALND and SLNB groups, with predominant visualization of lymphatic flow and/or lymph nodes in the arm and axilla in the ALND group (P=0.01) (Figure 2) and of extra-axillary lymph nodes only in the ALND group (P<0.01), as shown in Table 3.
There was no significant difference in the total number of lymph nodes identified between the ALND and SLNB groups. However, there was a significant difference in the distribution of lymph nodes in these groups. The cubital lymph node was more frequently visualized in the immediate Dynamic imaging in the ALND group (P=0.004), while the axillary lymph nodes were more frequently visualized in the delayed imaging (WBS) in the SLNB group (P<0.01) (Figure 3). The deltopectoral lymph node was identified only in the ALND group (Figure 4), but without a significant difference, as shown in Table 4.