CT-based evaluation of axillary sentinel lymph node status in breast cancer: value of added contrast-enhanced study.
OBJECTIVE
To evaluate the diagnostic reliability of CT-based sentinel lymph node (SLN) size criteria for selecting the candidates for direct axillary dissection without SLN biopsy and to determine the value of added contrast-enhanced study.


METHODS
Breast cancer patients (n = 107) underwent triple phasic (1-min, 3-min, 8-min) contrast-enhanced 5 mm-computed tomography (CT) of the breasts and axillae. In the CT image, the most inferior lymph node in the axilla was designated the SLN. Axillary status was judged based on SLN size criteria. CT density, enhancement rate, and peak enhancement time of each SLN were correlated with histopathological results.


RESULTS
SLN size criteria demonstrated a sensitivity of 76% and a positive predictive value of 95% in predicting SLN metastasis. The density values at each scanning time-point were significantly different for metastatic and non-metastatic SLN. However, their enhancement rates differed significantly only at 1 min. Their peak enhancement occurred primarily at 1 min. The use of contrast-enhancement criteria improved the predictive sensitivity, but failed to decrease the false-positive rate of the SLN size criteria.


CONCLUSIONS
The enhancement rate at 1 min proved to be the most useful parameter in contrast-enhanced CT studies; however, it failed in improving the accuracy of the SLN size criteria.
Yuen
S
S
Department of Radiology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Japan. s.yuen@scchr.jp
Yamada
K
K
Goto
M
M
Sawai
K
K
Nishimura
T
T
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001365:Axilla; D001943:Breast Neoplasms / Q000473:pathology*; D003287:Contrast Media; D005260:Female; D006801:Humans; D008198:Lymph Nodes / Q000000981:diagnostic imaging*; D008207:Lymphatic Metastasis / Q000000981:diagnostic imaging; D008875:Middle Aged; D011237:Predictive Value of Tests; D012680:Sensitivity and Specificity; D021701:Sentinel Lymph Node Biopsy; D014057:Tomography, X-Ray Computed
D003287:Contrast Media