Ultrasonographic changes of submandibular glands in irradiated patients for head and neck cancers

Salivary glands (SGs) are usually irradiated during radiotherapy for head and neck cancers, which may lead to radiation-induced changes. These changes could be evaluated safely by ultrasonography; however, there have been few studies in this regard. Thus, we aimed to investigate the changes in post-radiotherapy submandibular glands using ultrasonography in patients undergoing head-neck radiotherapy.

We evaluated 46 submandibular glands of 23 patients ultrasonographically in terms of echogenicity, echotexture, margin, and dimensional (anteroposterior, superoinferior, mediolateral length and volume) changes before radiotherapy, and at the second and sixth months after radiotherapy.

About 93.5% of the submandibular glands were hyperechoic before RT. When the same submandibular glands were evaluated two months later, 39.1% were hyperechoic. Six months after the therapy, 56,5% were hyperechoic (p<0.001). There is also a similar trend for the echotexture (p<0.001) and the regularity margins before RT, two months after-, and at sixth month after RT (p<0.001). Also, there were statistically significant differences between anteroposterior, superoinferior, mediolateral lengths, and volumetric values measured before radiotherapy and at the end of two and six months after radiotherapy onset (p<0.001).

We revealed that submandibular glands were isoechoic or hypoechoic, heterogeneous, and irregular after radiotherapy; however, as the time elapsed after radiotherapy, the parenchyma structure returned to normal in half of them. Indeed, defining radiotherapy-related changes in SGs may be helpful in better understanding the mechanism of common oral complications associated with RT, and in the differential diagnosis of other SG diseases.