ESTRO 2024 - Abstract Book

S5947

RTT - Treatment planning, OAR and target definitions

ESTRO 2024

[4] About the non-consistency of PTV-based prescription in lung [Lebredonchel S, et al 2017]

[5] Monte Carlo and ray tracing algorithms in the cyberknife treatment planning for lung tumours-comparison and validation. [V.Murali et al, 2012]

[6] Dosimetric evaluation of Acuros XB Advenced Dose Calculation algorithm in heterogeneous media. [Antonella Fogliata et al, 2011]

[7] Report dose-to-medium in clinical trials where available; a consensus from the global Harmonisation group to maximize consistency. [Kry S et al, 2021]

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Digital Poster

Hearing loss after cranial radiation in children: a dosimetry study from the French registry PediaRT

William Gehin, Valérie Bernier

Institut de Cancérologie de Lorraine, Radiotherapy, Vandoeuvre les Nancy, France

Purpose/Objective:

To identify dosimetric predictive factors of sensorineural hearing loss (SNHL) in children after cranial radiation therapy (RT) in a single institution using dosimetric data from the French National Registry PediaRT.

Material/Methods:

Complete audiological follow-up data were available for 44 children treated with cranial RT between 2014 and 2021 at our institution. The median age at the time of RT initiation was 9 years (range: 2-17 years). No children presented with hearing loss prior to treatment. SNHL was defined as a Chang ototoxicity grade ≥ 1a or higher.

Results:

Median audiometric follow-up duration was 51 months. Seven children (16%) developed SNHL with a median time to occurrence of 33 months (range, 18-46 months). The estimated SNHL cumulative rate at 2 years post-RT was 4,5% ± 3,1% and at 5 years was 21% ± 7.2%. Multiple Cox regression models showed that the association of the age at radiotherapy and the dosimetric values to the inner ear canal and cochlea were the most significant predictive factors of SNHL occurrence. No child who received less than 35 Gy on average to the cochlea (n=26) suffered from SNHL, whereas the 5-year SNHL cumulative incidence for the children who received greater than or egal to 35 Gy on average to the cochlea (n=18) was 51.8% ± 15.1%.