ESTRO 2025 - Abstract Book

S759

Clinical - CNS

ESTRO 2025

Fig. 2

Table 1

Results: There was considerable variability in D mean and D max across the limbic system (Fig. 2). Here, we report preliminary dose ranges for D mean values of Amygdala and Hippacampus ipsilateral and Fornix. For the Amygdala the mean dose was 6.80 Gy (95% CI: 5.83–7.78 Gy), with a range of 17.47 Gy (minimum: 1.80 Gy, maximum: 19.27 Gy). Fornix showed a mean dose of 16.55 Gy (95% CI: 14.87–18.24 Gy) and a range of 29.06 Gy (minimum: 4.60 Gy, maximum: 33.66 Gy). The Hippocampus mean dose was 13.67 Gy (95% CI: 12.11–15.23 Gy), with a range of 33.94 Gy (minimum: 5.23 Gy, maximum: 39.17 Gy) (Table 1). The PTV volume was 175,6 cm 3 Conclusion: While the full analysis is ongoing, these interim results suggest significant interinstitutional variability in limbic system dose sparing. Currently, constraints for the Hippocampus within the limbic system already exist, however similar constraints are not yet established for other limbic structures like the Amygdala or Fornix. Expanding these constraints to additional limbic regions may provide a more comprehensive approach to preserving cognitive outcomes while maintaining treatment efficacy.

Keywords: limbic system, cognition, High-grade glioma

References: (1)C. Sorce et al. , “Recommendation for the contouring of limbic system in patients receiving radiation treatment: A pictorial review for the everyday practice and education,” Mar. 01, 2021, Elsevier Ireland Ltd . doi: 10.1016/j.critrevonc.2021.103229.