Radiation induced plexopathy results after radiation treatment is targeted at pelvic malignancies. It typically presents with motor and sensory changes in lower extremities (LEs), although, due to the various anatomic sites that are irradiated, the presentation can vary. RIP is a rare but severe side effect that can impact quality of life and is usually a diagnosis of exclusion. To date there is no effective treatment.  We report a case in which hyperbaric oxygen (HBO) treated RIP.

A 64-year-old man with history of prostate cancer status post 39 radiation treatments reported progressive bilateral LE parasthesias and weakness a few months after radiation.  His examination showed mild diffuse weakness in bilateral LEs and decreased sensation in patchy distribution in bilateral LEs and saddle region. EMG showed bilateral thoracic radiculopathy, L5 radiculopathy and S1 radiculopathy.  MRI of the entire spine was unremarkable.  CSF analysis was negative for malignant, infectious or inflammatory etiologies.  Therefore, symptoms were attributed to radiation induced plexopathy.  He was started on hyperbaric oxygen therapy.  After completing 24 treatments, patient reported improvement in symptoms.  Bilateral lower extremity and saddle anesthesia had resolved.  He also had improvement in lower extremity strength.

Radiation-induced plexopathy (RIP) is a rare side effect of radiation that can lead to significant disability and difficulty in performing activities of daily living.  Due to increasing survival rates of cancer patients, the incidence of RIP has increased as well. At this time, RIP is typically thought to be irreversible and management is primarily supportive care. Our patient with RIP was treated with hyperbaric oxygen therapy and had significant improvement in symptoms.  Given the impairment in function this condition can cause, we suggest a trial of HBO be considered for all patients with RIP.