Quantitative Multiparametric Ultrasound (mpUS) in the Assessment of Inconclusive Cervical Lymph Nodes

SIMPLE SUMMARY: Persisting cervical lymphadenopathy should be further evaluated to distinguish benign infectious enlargements from malignant diseases such as cancer of the upper airway tract, with head and neck squamous cell carcinoma or lymphatic diseases being the most common ones. Ultrasound (US) remains the primary imaging modality for assessment of cervical lymph nodes (CLN) due to their superficial localization. We aimed to investigate whether US examination and classification of CLN can be improved by adding multiparametric applications to the established B-mode–US technique by evaluating tissue stiffness and micro-vascularization. Our results show that tissue stiffness was significantly higher in malignant CLN, even in subgroups without B-mode criteria indicating malignancy. Shear wave elastography is an easy, fast and noninvasive tool available on most US devices today. This may help to detect malignant CLN with higher accuracy and help patients in cancer aftercare to detect recurrent CLN metastasis and to consecutively assess necessary treatment faster. ABSTRACT: Background: Enlarged cervical lymph nodes (CLN) are preferably examined by ultrasound (US) by using criteria such as size and echogenicity to assess benign and suspicious CLN, which should be histologically evaluated. This study aims to assess the differentiation of malign and benign CLN by using multiparametric US applications (mpUS). Methods: 101 patients received a standardized US protocol prior to surgical intervention using B-mode–US, shear-wave elastography (SWE) and contrast-enhanced ultrasound (CEUS). SWE was assessed by 2D real-time SWE conducting a minimum of five measurements, CEUS parameters were assessed with post-processing perfusion software. Histopathological confirmation served as the gold standard. Results: B-mode–US and SWE analysis of 104 CLN (36 benign, 68 malignant) showed a significant difference between benign and malignant lesions, presenting a larger long axis and higher tissue stiffness (both p < 0.001). Moreover, tissue stiffness assessed by SWE was significantly higher in CLN with regular B-mode–US criteria (Solbiati Index > 2 and short-axis < 1 cm, p < 0.001). No perfusion parameter on CEUS showed a significant differentiation between benign and malignant CLN. Discussion: As the only multiparametric parameter, SWE showed higher tissue stiffness in malignant CLN, also in subgroups with regular B-mode criteria. This fast and easy application may be a promising noninvasive tool to US examination to ameliorate the sonographic differentiation of inconclusive CLN.