Whole-Brain Radiation to Treat a Recurrent Malignant Subdural Effusion.

We report the first case of a recurrent malignant subdural effusion that was treated with whole-brain radiation therapy. A 72-year-old man presented with headaches and de novo left central facial palsy and right upper extremity weakness. His past medical history was remarkable for a prostatic adenocarcinoma diagnosed in 1999 (T4N0M0) with no metastatic disease diagnosed to date. Brain magnetic resonance imaging with gadolinium showed carcinomatous meningitis and a 1.5-cm thick left hemisphere subdural collection causing a mass effect. Left-side frontal and parietal burr holes were created and a clear effusion was successfully drained under high pressure. A biopsy od the dura mater was also taken. Analysis of the effusion showed a protein concentration of 1233 mg/dL. Histopathological examination of the dura matter showed adenocarcinomatous cells. Despite the clinical improvement, serial postoperative computed tomography scans of the head showed massive recurrence of the subdural effusion. The patient was offered radiation therapy as a palliative treatment for effusion control. Whole-brain radiation therapy was performed from day 10 to 17 after surgery at a palliative dose of 20 Gy in 5 fractions. No treatment-associated complications were reported. Thirty days after radiotherapy, the computed tomography scan of the head showed total resolution of the malignant effusion.