Does shear wave elastography for medullary thyroid carcinoma predict lateral cervical lymph node metastasis?

To assess whether shear wave elastography (SWE) for medullary thyroid carcinoma (MTC) can independently predict lateral cervical lymph node metastasis (LNM).Patients with MTC who were treated via primary surgery between January 2015 and May 2020 and who had undergone preoperative SWE and ultrasound (US) examinations in the Harbin Medical University Cancer Hospital were retrospectively studied. The relationships between lymphatic status and the clinicopathological and imaging characteristics were evaluated. Afterwards, associations between lateral cervical LNM and SWE parameters, as well as sex, age, invasive size, extrathyroidal extension (ETE), preoperative calcitonin levels, and US features were assessed by using multivariable logistic regressions.A total of 76 patients (31 men and 45 women, 48.1 ± 11.8 years) were evaluated. The following factors demonstrated significant associations with lateral cervical LNM: the male sex (P = 0.015), an age ≤ 35 years (P = 0.049), an invasive size > 1.0 cm (P = 0.028), ETE (P = 0.005), a preoperative calcitonin level > 60 pg/ml (P < 0.001), irregular shape on the US (P = 0.001), the presence of a non-circumscribed margin on the US (P = 0.009), an Emax > 66 kPa (P < 0.001), an Emean > 37.5 kPa (P < 0.001), and an ER > 1.65 (P = 0.002). In the multivariable analysis, an age ≤ 35 years (P = 0.049), a preoperative calcitonin level > 60 pg/ml (P = 0.004), an irregular shape on the US (P = 0.036), and an Emax > 66 kPa (P = 0.011) maintained independent significance.Emax was demonstrated to be an independent predictor for lateral cervical LNM of MTC. SWE may serve as a noninvasive method of preoperative lateral cervical LNM risk assessment for MTC.