Impact of delayed lymphoscintigraphy for sentinel lymphnode biopsy for breast cancer.

Background: Despite universal adoption of sentinel lymph node biopsy (SLNB) for breast cancer, there remains no standardized protocol for preoperative lymphoscintographic assessment of sentinel nodes. Both immediate and delayed lymphoscintigraphy are currently utilized, although it is unclear how delayed imaging impacts SLN identification.

Methods: Among patients diagnosed with breast cancer who underwent SLNB at Duke from 2011 to 2012, two protocols for preoperative lymphoscintigraphy were used: protocol A included both immediate and delayed lymphoscintigraphy (n = 152), while protocol B involved immediate lymphoscintigraphy only (n = 103).

Results: The overall intraoperative SLN identification rate was 98.4% and did not differ between groups. A lower number of SLN were visualized on the immediate scan using protocol A compared to protocol B (P < 0.001). Although a greater total number of nodes was excised using protocol A, this result was not statistically significant (P = 0.08). Moreover, there was no significant difference in the number of negative SLN between groups (P = 0.51).

Conclusions: We found no significant impact on identification rate or number of SLN excised with the use of delayed versus immediate imaging. These findings support abandoning delayed lymphoscintographic imaging, except in those cases where aberrant drainage is suspected.