Evaluation of the Brachial Plexus With Shear Wave Elastography After Radiotherapy for Breast Cancer.

OBJECTIVES: The aim of this study was to analyze the elasticity characteristics of the brachial plexus by shear wave elastography (SWE) in patients receiving radiation therapy (RT) for breast cancer and to compare them with their contralateral brachial plexus to evaluate whether elasticity properties can be used as supporting findings for the early diagnosis of brachial plexus involvement in patients receiving RT.

METHODS: A prospective analysis with electromyography and SWE was performed on 23 brachial plexuses of patients receiving RT for breast cancer and their contralateral brachial plexuses. An electromyographic device was used for nerve conduction studies. Evaluations were done by the same investigator, and superficial electrodes were used in the recordings. A quantitative analysis of the brachial plexus with SWE was performed, with values in kilopascals on a color scale ranging from 0 (red, soft) to 150 (dark blue, hard) kPa.

RESULTS: Mean SWE values ± SD were 51.0 ± 14.0 kPa for the ipsilateral brachial plexuses of patients receiving RT and 18.0 ± 4.2 kPa for the contralateral brachial plexuses. Statistically significant differences were observed between the groups in the analysis of SWE values (P < .001). No significant correlation was found between the nerve conduction parameters and elastographic values (P > .05).

CONCLUSIONS: Shear wave elastography showed that the brachial plexuses of patients receiving RT were stiffer than the unaffected brachial plexuses. Brachial plexus stiffening may be associated with fibrotic processes.