Table 6:

Small (collimated), non-uniform field condition: brain-absorbed dose of radiation and excess relative risk of developing brain tumors as a function of patient age

Age, yMSD, Both Planes, mGySD, Both Planes, mGyBrain Dose–to–MSD Conversion FactorBrain-Absorbed Dose, mGyProjected Risk of Developing Brain Tumors (×Baseline)
<1372.9361.20.1447.92.1
1–2443.5434.40.1146.32.1
3–7383.3398.90.0928.01.6
8–12355.3341.90.0514.81.3
13–17521.3529.70.0313.01.3
18–21583.5729.30.0313.91.3
All ages422.74400.0818.01.4
  • Note:—Projected risk is calculated as (excess relative risk = 0.023/mGy)+1.

  • SD indicates standard deviation (inter-patient variability).