# How Effective Is Radiotherapy in the Ultrasonographic Structural Characteristics of the Submandibular Glands?

## TL;DR

This study examines how radiotherapy affects the structure of submandibular glands using ultrasound, finding significant changes linked to radiation dose.

## Contribution

The study provides new insights into structural changes in submandibular glands post-radiotherapy using ultrasonography.

## Key findings

- Radiotherapy causes significant changes in echogenicity, echotexture, and margin of submandibular glands.
- Higher radiation doses correlate with more pronounced structural changes in gland texture and margin.
- Gland structure tends to partially recover over time after radiotherapy.

## Abstract

Radiotherapy affects salivary glands more intensely than it does other organs, and salivary gland dysfunction can continue during or after treatment. The aim of this study was to examine structural alterations in submandibular glands through ultrasonography following head-neck radiotherapy in patients and to evaluate the impact of radiation dose on these modifications.

Forty-six submandibular glands were assessed ultrasonographically for the changes in echogenicity, echotexture, and margin and the influence of the radiation dose on these changes before radiotherapy at 3 time points: the second and sixth months following starting treatment. Statistical analysis of the data was performed using a chi-square test.

Significant relationship in 3 ultrasonographic structural characteristics—echogenicity, echotexture, and margin— of submandibular glands (P < .001, P < .001, and P < .001, respectively) were observed before and at the second and sixth months after radiotherapy. There was found a significant correlation between the radiation dose groups in the change of echotexture at 2 different time periods after radiotherapy (P < .001, P < .05, respectively) and in the change of margin at the second month after radiotherapy onset (P < .05).

Preceding radiotherapy, submandibular glands typically exhibited hyperechoic echogenicity, homogeneous ecotextures, and regular margins. However, after radiotherapy, there was an observable transformation characterized by isoechoic/hypoechoic features, heterogeneous textures, and irregular margins. With the passage of time following radiotherapy, there was a tendency for the parenchyma structure to gradually revert to a normal state. Also, the radiation dose generally has an effect on the structural changes of the submandibular glands.