Scintimammography in the evaluation of axillary lymph node invasion in patients with breast cancer

RESUMO

Purpose. To correlate axillary Technetium-99m-sestamibi uptake with the axillary histology in patients with proven breast cancer. Secondly, to correlate the breast scintimammography results with the tumor histology. Materials and methods. Fifty-one patients with operable breast cancer T1, T2 or T3 and N0 or N1 had a scintimammography before surgery. Images were interpreted directly from the computer screen by two specialists who did not have knowledge about clinical or radiological information concerning the patients. Surgical treatment included conservative surgery or mastectomy, both followed by axillary dissection for malignant tumors (45 patients) and only excision for benign lesions (6 patients). Statistical analysis correlated scintimammography and histologic results. Results. The sensitivity and specificity of Tc99m-sestamibi to assess histologic lymph node involvement in patients with operable breast cancer was 35 percent (95 percent CI:14-61 percent) and 57 percent (95 percent CI:37-75 percent) respectively. The positive predictive value was 33 percent (95 percent CI:13-58 percent) and the negative predictive value was 59 percent ( 95 percent CI: 38-77 percent). The sensitivity and specificity of Tc99-sestamibi to assess breast tumor malignancy was 97 percent (95 percent CI:88-99 percent) and 33 percent (95 percent CI: 4-77 percent) respectively, calculated in only six patients. The positive predictive value was 91 percent (95 percent CI: 80-97 percent) and the negative predictive value was 66 percent (95 percent CI:9-99 percent). Conclusion. Our findings regarding the preoperative axillary assessment with Tc99m-sestamibi do not support the use of this imaging modality for this purpose