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Table 2 A summary of hippocampal dosimetric parameters used in this study

From: Hippocampal dosimetry correlates with the change in neurocognitive function after hippocampal sparing during whole brain radiotherapy: a prospective study

  Bilateral hippocampi Left hippocampus Right hippocampus
  Mean (95 % CI) Median Mean (95 % CI) Median Mean (95 % CI) Median
Volume (c.c.) 4.99 (4.59–5.40) 5.18 2.41 (2.20–2.62) 2.41 2.58 (2.37–2.79) 2.71
Maximum EQD2 (Gy) 13.51 (11.85–15.17) 12.64 13.20 (11.50–14.9) 12.41 12.93 (11.64–14.22) 12.64
D20% EQD2 (Gy) 8.30 (7.81–8.78) 8.26 8.34 (7.86–8.82) 8.22 8.27 (7.78–8.76) 8.28
D40% EQD2 (Gy) 7.65 (7.19–8.11) 7.68 7.67 (7.22–8.12) 7.70 7.63 (7.16–8.10) 7.70
D50% EQD2 (Gy) 7.40 (6.96–7.85) 7.45 7.41 (6.97–7.85) 7.48 7.37 (6.92–7.82) 7.47
D80% EQD2 (Gy) 6.70 (6.32–7.07) 6.80 6.72 (6.35–7.09) 6.73 6.69 (6.30–7.07) 6.84
Minimum EQD2 (Gy) 5.78 (5.51–6.04) 5.82 5.61 (5.04–6.18) 5.73 5.86 (5.58–6.14) 5.90
  1. Abbreviations: D 10% biologically equivalent dose in 2-Gy fractions (EQD2) assuming α/β = 2Gy to 10 % of the hippocampus volume of interest (left, right, or bilateral); therefore, Dm% is defined as the EQD2 to m% of the hippocampal volume of interest; D100% = the EQD2 to 100 % of the structure volume, corresponding to the minimal dose received by the hippocampus of interest in our study; Maximum the maximal EQD2 irradiating the hippocampus volume of interest