Preoperative lymphoscintigraphy for breast cancer does not improve the ability to identify axillary sentinel lymph nodes

Objective To evaluate the role of preoperative lymphoscintigraphy in sentinel lymph n ode (SLN) biopsy for breast cancer. Summary Background Data Numerous studies have demonstrated that SLN biopsy can be used to stage axi llary lymph nodes for breast cancer. SLN biopsy is performed using injectio n of radioactive colloid, blue dye, or both. When radioactive colloid is us ed, a preoperative lymphoscintigram (nuclear medicine scan) is often obtain ed to ease SLN identification. Whether a preoperative lymphoscintigram adds diagnostic accuracy to offset the additional time and cost required is not clear. Methods After informed consent was obtained, 805 patients were enrolled in the Univ ersity of Louisville Breast Cancer Sentinel Lymph Node Study, a multiinstit utional study involving 99 surgeons. Patients with clinical stage T1-2, NO breast cancer were eligible for the study. Ail patients underwent SLN biops y, followed by level I/II axillary dissection. Preoperative lymphoscintigra phy was performed at the discretion of the individual surgeon. Biopsy of no n-axillary SLNs was not required in the protocol. Chi-square analysis and a nalysis of variance were used for statistical comparison. Results Radioactive colloid injection was performed in 588 patients. In 560, peritu moral injection of isosulfan blue dye was also performed. A preoperative ly mphoscintigram was obtained in 348 of the 588 patients (59%). The SLN was i dentified in 221 of 240 patients (92.1%) who did not undergo a preoperative lymphoscintigram, with a false-negative rate of 1.6%. In the 348 patients who underwent a preoperative lymphoscintigram, the SW was identified in 310 (89.1%), With a false-negative rate of 8.7%, A mean of 2.2 and 2.0 SLNs pe r patient were removed in the groups without and with a preoperative lympho scintigram, respectively. There was no statistically significant difference in the SLN identification rate, false-negative rate, or number of SLNs rem oved when a preoperative lymphoscintigram was obtained. Conclusions Preoperative lymphoscintigraphy does not improve the ability to identify ax illary SLN during surgery, nor does it decrease the false-negative rate. Ro utine preoperative lymphoscintigraphy is not necessary for the identificati on of axillary SLNs in breast cancer.