IMRT 2018

QUANTEC: Recommended Dose Limits

▪ The Emami estimate (5% probability @5 years for 50Gy) is an over estimate => incidence ≈ 0% ▪ The risk increases (fractionation 1.8-2.0 Gy) ▪ 3–7% in the region of 55–60 Gy ▪ >7–20% for doses >60 Gy ▪ a / b is likely small <2 Gy

Mayo C, Martel MK, Marks LB, Flickinger J, Nam J, Kirkpatrick J. Radiation dose-volume effects of optic nerves and chiasm. Int J Radiat Oncol Biol Phys. 2010 Mar 1;76(3 Suppl):S28-35.