Comparing study of positron emission tomography and ultrasonography in the detection of axillary lymph node metastasis in patients with early stage breast cancer

Abstract

616 Background: The current status of axillary lymph node is the most important prognostic factor in breast cancer. Axillary lymph node dissection (ALND) is currently the standard option for assessment of axillary lymph nodes. Positron emission tomography - computerized tomography (PET-CT) imaging and breast sonography are a noninvasive imaging modality that can detect malignant lymph node. The purpose of this study was to evaluate the clinical usefulness of axillary lymph node staging by means of PET-CT imaging compare with breast sonography in breast cancer. Methods: This study involves 129 breast cancer patients and clinically negative axillary node. All patients had whole body PET-CT imaging and breast sonography before SLN biopsy. After SLN biopsy, all patients underwent complete ALND. Axillary lymph nodes were evaluated by standard hematoxylin and eosin staining techniques, while sentinel nodes were further examined for micrometastatic disease. The findings of PET-CT imaging and breast sonography of 129 patients were compared with pathologic findings after operation. Diagnostic accuracy was evaluated applying ROC curve areas. Results: The sensitivity of PET-CT imaging was 60.0%; specificity and accuracy were 83.6% and 73.4%, respectively. The sensitivity, specificity and accuracy of breast sonography were 61.8%, 89.0%, and 77.3% respectively. The SUVs of axillary lymph node ranged from 0.0 to 7.01. Analysis using ROC curves revealed the area under each curve which indicated a diagnostic accuracy. For involvement of axillary lymph node, PET-CT imaging had the area under the curve of 0.735, breast sonography one of 0.769. Conclusions: Axillary lymph node staging using PET-CT imaging is inferior to the breast sonography in early stage of breast cancer patients. Our study reveals the value of PET-CT imaging is not good compare to the breast sonography in the detection of axillary lymph nodes metastasis in patients with early breast cancer. No significant financial relationships to disclose.