A study of the assessment of axillary lymph nodes before surgery for breast cancer using multidetector-row computed tomography

Abstract

Sentinel lymph node biopsy (SLNB) is widely used in the detection of breast cancer metastasis, and a retrospective study was conducted to determine whether the preoperative assessment of axillary lymph node metastasis using multidetector-row computed tomography (MDCT) images would contribute to the selection of patients who require SLNB. Seventy of the 164 patients who underwent surgery of the breast during the period of April 2006 to December 2008 were selected as subjects who: (1) did not undergo preoperative chemotherapy; (2) had undergone MDCT before the surgery; (3) had undergone either SLNB or axillary lymph node removal during the operation; and (4) whose T factor was pathologically T2 or less. The diameter and shape of the largest lymph node that was identified on an MDCT image of the axilla on the affected side were measured and compared with permanent pathological specimens. Size: The group with lymph node metastasis included 21 subjects with an average diameter of the largest lymph node of 10.3 mm (range, 6-23 mm), and the nonmetastasis group included 49 subjects with that of 7.1 mm (5-13 mm). Shape: Round lymph nodes that internally contained no fat concentration in 24 subjects, and cuneate or round lymph nodes that internally contained a fat concentration in 46 subjects. The observable lymph nodes that were round had a diameter of at least 10 mm, and internally contained no fat concentration (A) were regarded as positive, whereas the cuneate or round lymph nodes that measured less than 8 mm in diameter and internally contained fat concentration (B) were regarded as negative, and both positive predictive value and negative predictive value was 100%. Axilla removal was performed from the beginning in the case of (A) by assessing the size and shape for the presence or absence of axillary lymph node metastasis before surgery using MDCT.