Radiation-induced brachial plexopathy: MR imaging.

OBJECTIVE: To describe the MR imaging appearance of radiation-induced brachial plexopathy.

DESIGN: MR imaging was performed in two patients with the clinical diagnosis of radiation-induced brachial plexopathy and in one with surgically proven radiation fibrosis of the brachial plexus.

PATIENTS: Three patients who had had radiation therapy to the axilla and supraclavicular region (two with breast carcinoma and one with Hodgkin's lymphoma) presented with symptoms in the arm and hand. To exclude metastases or tumor recurrence MR imaging was performed.

RESULTS AND CONCLUSION: In one patient, fibrosis showing low signal intensity was found, while in two patients high signal intensity fibrosis surrounding the brachial plexus was found on the T2-weighted images. In one case gadolinium enhancement of the fibrosis was seen 21 years after radiation therapy. It is concluded that radiation-induced brachial plexopathy can have different MR imaging appearances. We found that radiation fibrosis can have both low or high signal intensities on T2-weighted images, and that fibrosis can enhance even 21 years after radiation therapy.