ESTRO 2023 - Abstract Book

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ESTRO 2023

the median age was 52 years [27-71].The tumor was classified as advanced stage in 65 % of cases (T4: 40%; T3: 25%; T2:20%; T1: 15%). Lymph node involvement was observed in 80% of cases. The mean dose received by 40% of the volume (V40%) was 12.7Gy [3-34Gy]. It was greater than 7.3Gy in 20 patients (66%). The mean Dmax was 45Gy [10-68Gy]. The Dmean at the hippocampi was on average at 14.4Gy [3-35Gy]. Those values were significantly higher in advanced tumors (T4) with respectively a V40%, Dmax, Dmean estimated on average at 19.8%, 53Gy, 20.5Gy versus 9.6%, 41.5Gy and 10.8Gy for the rest of the stages (p<0.001). Conclusion the dose to the hippocampi should be evaluated in the initial treatment planning of radiotherapy for patients with NPC especially in an advanced stage (T4) as it affects young patients who may suffer from memory problems. This optimization of the hippocampi dose is suitable to preserve the quality of life of this population who are in majority active and productive individuals.