Quantitative kinetic parameters of primary tumor can be used to predict pelvic lymph node metastasis in early-stage cervical cancer

To investigate the role of kinetic parameters of primary tumor derived from dynamic contrast-enhanced MRI (DCE-MRI) in predicting pelvic lymph node metastasis (PLNM) in patients with cervical cancer.

66 women with newly diagnosed cervical cancer were included between July 2017 and August 2019. All patients had a FIGO stage IB-IIA cancer and treated with hysterectomy and bilateral lymphadenectomy. Kinetic parameters of the primary tumor were derived from DCE-MRI data. The tumor diameter, ADC value, kinetic parameters, and nodal short-axis diameter were compared between patients with or without PLNM. Logistic regression analysis was used to determine the independent predictors for PLNM and receiver operator characteristic curve was used to evaluate the predictive performance.

There were 20 patients with PLNM and 46 patients without PLNM. Tumor diameter, the efflux rate constant (K_ep), and nodal short-axis diameter were significantly higher in patients with PLNM (P < 0.01). Multivariate logistic regression analysis showed that K_ep and short-axis diameter were independent predictors for PLNM. Combining K_ep and nodal short-axis diameter yielded the highest area under the curve (AUC) of 0.839. Combined with K_ep, the sensitivity, specificity, negative predictive value, and positive predictive value of nodal short-axis diameter increased from 0.500, 0.957, 0.815, and 0.833 to 0.600, 0.978, 0.923, and 0.849, respectively. With 1.113 min⁻¹ as threshold, the sensitivity and specificity values of K_ep in predicting PLNM in patients with normal-sized lymph nodes were 0.909 and 0.667, respectively.

K_ep of primary tumor can be used as a surrogate marker to predict PLNM in cervical cancer.