Differentiation of metastatic from non-metastatic lymph nodes in patients with uterine cervical cancer using diffusion-weighted imaging.

OBJECTIVE

This study aims to determine the diagnostic value of diffusion-weighted imaging (DWI) in the differentiation of metastatic lymph nodes from non-metastatic lymph nodes in uterine cervical cancer.

METHODS

In 42 patients who underwent lymph node dissection for uterine cervical cancer, conventional MRI and DWI examinations were performed before surgery. Of the 1109 total dissected pelvic lymph nodes, 188 enlarged nodes with a short-axis diameter of 5mm or greater were included for further analysis. Each of the size-based criteria (i.e., short-axis diameter and long-axis diameter) and ADC-based criteria (i.e., mean ADC, minimum ADC, mean rADC (relative ADC) and minimum rADC) were compared between metastatic lymph nodes and non-metastatic lymph nodes.

RESULTS

There were statistically significant differences between metastatic and non-metastatic lymph nodes in the short-axis diameter, long-axis diameter, mean ADC, minimum ADC, mean rADC and minimum rADC (P < 0.001). The Az of the minimum ADC (0.990) was greater than that of the other ADC-based criteria (0.974, 0.939, 0.976 for mean ADC, mean rADC and minimum rADC, respectively) and all size-based criteria (0.878 for short-axis diameter and 0.858 for long-axis diameter) (P < 0.05). Using the minimum ADC criteria (≤ 0.881 × 10⁻³ mm²/s), the sensitivity and specificity for differentiating metastatic from non-metastatic lymph nodes were 95.7% and 96.5%, respectively.

CONCLUSIONS

DWI is feasible for differentiating metastatic from non-metastatic pelvic lymph nodes in patients with uterine cervical cancer and minimum ADC could be served as a representative marker.