We know that hippocampal avoidance reduces neurocognitive toxicity from whole brain radiation, but does it help when treating primary brain tumors? Using data from a randomized trial comparing 60 Gy in 30 versus 20 fractions for GBM, this dosimetric study found that mean dose specifically to the left hippocampus was associated with a decline in mini mental status exam (MMSE) scores after radiation. Dose to the right hippocampus was not associated with significantly associated with MMSE decline. A post-hoc analysis found that knowledge-based planning to avoid the left hippocampus resulted in a 43% reduction in mean dose while maintaining the same target coverage.
- Fang, Radiother Oncol 2022