The logistic regression analysis of ultrasonographic features in differential diagnosis of cervical lymph nodes metastasis of nasopharyngeal carcinoma patients

We performed a logistic regression analysis to evaluate the predictive value of ultrasonongraphy-detectable features of cervical lymph nodes in patients with nasopharyngeal carcinoma. The goal of this analysis was to determine whether certain ultrasound features were useful for accurate differential diagnosis of cervical lymph nodes metastasis with underlying nasopharyngeal carcinoma. In this investigation 220 "first-visit" patients with nasopharyngeal carcinoma were subjected to cervical lymph node examination by ultrasonography and all nodes underwent histological evaluation by core needle biopsy. A total of 303 lymph nodes (74.8% of all nodes examined (N = 405)) were found to contain malignant metastasis. Using logistic regression analysis, four ultrasonographic features were identified as significant predictor variables for differentiating between benign and malignant cervical lymph nodes. These features were the maximum long axis, minimum short axis, short and long axis ratio, and resistive index as determined by color flow Doppler ultrasonography. Our logistic regression model of ultrasound-detectable features may be useful on a larger scale for differential diagnosis of cervical lymph nodes involvement in nasopharyngeal carcinoma.