Reirradiation Tolerance of the Human Brain

Radiation-induced normal brain tissue necrosis is found to occur at NTDcumulative >100 Gy. The applied reirradiation dose and NTDcumulative increases with a change in irradiation technique from conventional to radiosurgery re-treatment, without increasing the probability of normal brain necrosis. Taken together, modern conformal treatment options, because of their limited volume of normal brain tissue exposure, allow brain reirradiation for palliative treatment of recurrent high grade glioma with an acceptable probability of radionecrosis.