Cauda equina tolerance to high-dose fractionated irradiation

Conclusions: This study suggests that the probability of neurotoxicity is a relatively steep function of dose to cauda equina (slope γ50 = approximately 3). The cauda equina tolerance is greater for females than males by about 11 CGE (at 2 CGE per fraction). Extended follow-up is necessary to accurately assess neurologic damage and then differentiate that phenomenon from local recurrence; the traditional 5-year assessment has limited meaning in this population. Local control remains an issue for these patients, even with the radical doses used.