5. Routine lymphoscimigraphy does not enhance success rates of sentinel lymph node dissection for breast cancer

Introduction: Lymphoscintigraphic (LS) images are often obtained prior to sentinel lymph node dissection (SLND) for breast cancer. The purpose of this study was to determine if routine LS enhances rates of identification of sentinel nodes (SN) in patients with breast cancer, and how often the SLND procedure is altered by LS findings. Methods: LS using 1 mCi of unfiltered technetium-99m sulfur colloid (QQ-4Tc) was performed on 105 consecutive patients undergoing SLND for invasive breast cancer. Four equal aliquots of 99 Tc were injected both intraparenchymally and intradermally in each patient around the palpable tumor or the tip of the localization wire. LS images were obtained at 2, 30, 60, and up to 120 minutes post-injection. Data was collected on LS identification of SN, patient weight/ height, biopsy type (core vs. excisional), tumor location (medial vs. lateral), and then compared to operative SN identification. Operative SLND utilized both 99 Tc and 1% lymphazurin blue dye. Results: LS failed to identify a SN in 6 of 105 cases (5.7%). Failed LS did not correlate with patient body weight/height, biopsy type, tumor location, or SN positivity. Failed LS did not predict operative SLND failure, as a SN was identified in 100% of cases (105/105), including the 6 failed LS. In 83% (5/6) of the failed LS, the SN was both hot and blue at operation. Internal mammary (IM) drainage was seen in 2% (2/105) of LS, but in both cases there was concomitant and predominant axillary drainage. Drainage outside of the ipsilateral axilla and IM chain was seen in one case of faint ipsilateral supraclavicular node drainage with concomitant axillary drainage. Positive SN were found in 26% (27/105) of all patients. Conclusions: There was no correlation with a failed LS and body habitus, biopsy type, SN positivity, or tumor location. Drainage to extraaxillary sites was rare, and was associated with concomitant axillary drainage. In this study routine LS did not enhance success of SLND or alter the surgical procedure.