Radiation-induced complications in endovascular neurosurgery: incidence of skin effects and the feasibility of estimating risk of future tumor formation.

Background: The incidence of radiation-induced complications is increasingly part of the informed consent process for patients undergoing neuroendovascular procedures. Data guiding these discussions in the era of modern radiation-minimizing equipment is lacking.
Objective: To quantify the rates of skin and hair effects at a modern high-volume neurovascular center, and to assess the feasibility of accurately quantifying the risk of future central nervous system (CNS) tumor formation.
Methods: We reviewed a prospectively collected database of endovascular procedures performed at our institution in 2008. The entrance skin dose and brain dose were calculated. Patients receiving skin doses >2 Gy were contacted to inquire about skin and hair changes. We reviewed several recent publications from leading radiation physics bodies to evaluate the feasibility of accurately predicting future cancer risk from neurointerventional procedures.
Results: Seven hundred two procedures were included in the study. Of the patients receiving >2 Gy, 39.6% reported subacute skin or hair changes following their procedure, of which 30% were permanent. Increasing skin dose was significantly associated with permanent hair loss. We found substantial methodological difficulties in attempting to model the risk of future CNS tumor formation given the gaps in our current understanding of the brain's susceptibility to low-dose ionizing radiation.
Conclusion: Radiation exposures exceeding 2 Gy are common in interventional neuroradiology despite modern radiation-minimizing technology. The incidence of side effects approaches 40%, although the majority is self-limiting. Gaps in current models of brain tumor formation after exposure to radiation preclude accurately quantifying the risk of future CNS tumor formation.