Occipital radionecrosis and neuroplasticity in astrocytoma

Background: Late-delayed complications after radiotherapy (RT) results from an imbalance between cell lesions and the protective capacities of the CNS. Temozolomide (TMZ) after RT may represent a potent radiosensitizing regimen. Although radionecrosis (RN) of the anterior visual pathway has been documented, in our opinion this is the first report of reversible visual field loss associated with occipital lobe radionecrosis. Case observation: We report a patient who suffered a left lateral homonymous hemianopia one year after radiochemotherapy (RCT) for an infiltrative low grade fibrillary astrocytoma. The visual field deficit was completely reversible after one month. Visual field defects have been described after the use of conventional external beam therapy for lesions near the anterior visual pathway. The cortex is relatively spared after RT. Conclusions: Given the new scientific data, we suppose that neuroplasticity may play a role in the reversibility of visual field deficit. At this time there is no proven treatment of radionecrosis. Homonymous hemianopia caused by occipital lesions are attributable to vascular disease and tumors, but take into account radiation effects. The risk of neurogenic visual loss must be factored into the decision to irradiate the whole brain.