FEB 01, 2013
The authors report an interesting case of a 26-year-old woman who developed bilateral radiation optic neuropathy and radiation necrosis of the right temporal lobe five years after radiation treatment. Following three doses of intravenous bevacizumab every three weeks, as well as dexamethasone and pentoxifylline, her vision improved dramatically and has remained stable over a three-year period. They say these results suggest that intravenous bevacizumab may be an effective treatment for radiation optic neuropathy.
The patient had undergone treatment of a tectal pilocytic astrocytoma with intensity-modulated radiation of 54 Gy in 30 fractions.
Her vision improved within four weeks of initiation of therapy with bevacizumab, dexamethasone and pentoxifylline, and there was complete resolution of brain and optic nerve enhancement within six weeks as demonstrated by MRI. After three years her vision improved from no light perception and 20/100 in her right and left eye, respectively, to 20/20 and 20/25, with improvement of bitemporal visual field defects despite the persistence of some subtle defects.
The authors note that although pentoxifylline was part of their patient's treatment protocol, its therapeutic efficacy remains unproven. However, bevacizumab has been reported to be effective for treatment of radiation necrosis of the central nervous system, and they believe it was responsible for their patient's visual improvement. Until these findings are confirmed in a randomized trial, they recommend that bevacizumab be considered in patients suffering from acute visual loss from radiation optic neuropathy.