Magnetic Resonance Imaging of Radiation-Induced Brachial Plexopathy

Abstract

This report illustrates the case of a 37-year-old woman following chemoradiotherapy for invasive ductal carcinoma of the right breast. The patient underwent surgery and received a radiation dose of 50 gray to the chest wall and 45 gray to the regional lymph nodes in 25 total fractions. She developed motor and sensory weakness in the right upper limb eight years after treatment. Brachial plexus neuropathy in cancer patients may result from either trauma to the plexus during surgery, the spread of cancer, or radiation therapy, and distinguishing between them may be difficult. The case highlights the importance of recognizing the signs, symptoms, and possible differential diagnosis of radiation-induced brachial plexopathy in cancer patients post-radiation therapy. It emphasizes the role of magnetic resonance imaging in the careful assessment and diagnosis of such a case.

Keywords: brachial plexus injury; non traumatic plexopathy; oncoradiology; palliative radiation therapy; radiation-induced brachial plexopathy.

Figure 1. Three-dimensional magnetic resonance neurography

The red circle indicates the thickened and edematous brachial plexus on the right, and the blue circle indicates the normal brachial plexus on the left.

Figure 2. STIR sequence of MRI in (A) coronal and (B) axial showing the thickened brachial plexus on the right (red circle) compared to the left (blue circle)

MRI, magnetic resonance imaging; STIR, short tau inversion recovery

Figure 3. Contrast-enhanced T1W MRI image showing a uniformly enhancing brachial plexus on the right (red circle)

MRI, magnetic resonance imaging; T1W, T1-weighted