Sonographic appearance of submandibular glands in patients treated with external beam radiotherapy for nasopharyngeal carcinoma

Purpose: The purpose of this study was to investigate the sonographic (US) appearances of submandibular glands in patients with nasopharyngeal carcinoma after external beam radiotherapy (RT) and compare them with those of healthy subjects. Methods: A total of 81 nasopharyngeal carcinoma patients treated with RT and 66 healthy subjects were recruited and underwent submandibular gland US. Bilateral submandibular glands were assessed for their size, echogenicity, echogenicity margin sharpness, and echotexture. Results: The mean ± SD transverse dimension of submandibular glands in patients treated with RT (2.5 ± 0.4 cm) was significantly smaller than that of healthy subjects (3.3 ± 0.4 cm) (p < 0.05). Submandibular glands in patients treated with RT tended to be heterogeneous (72%) with hypoechoic areas (46%) and ill-defined margins (89%). However, there were no statistically significant differences in echogenicity and conspicuity of intraglandular ducts of submandibular glands between patients and healthy subjects. Conclusions: RT-induced changes of the submandibular glands were demonstrated on US. J Clin Ultrasound, 41:472-478, 2013.