%0 Journal Article
%A Gillmann, Clarissa
%A Jäkel, Oliver
%A Karger, Christian
%T RBE-weighted doses in target volumes of chordoma and chondrosarcoma patients treated with carbon ion radiotherapy: Comparison of local effect models I and IV.
%J Radiotherapy and oncology
%V 141
%@ 0167-8140
%C Amsterdam [u.a.]
%I Elsevier Science
%M DKFZ-2019-02260
%P 234-238
%D 2019
%Z 2019 Dec;141:234-238
%X To compare the relative biological effectiveness (RBE)-weighted dose distributions in the target volume of chordoma and chondrosarcoma patients when using two different versions of the local effect model (LEM I vs. IV) under identical conditions.The patient collective included 59 patients treated with 20 fractions of carbon ion radiotherapy for chordoma and low-grade chondrosarcoma of the skull base at the Helmholtzzentrum für Schwerionenforschung (GSI) in 2002 and 2003. Prescribed doses to the planning target volume (PTV) were 60 (n = 49), 66 (n = 2) and 70 (n = 8) Gy (RBE). The original treatment plans that were initially biologically optimized with LEM I, were now recalculated using LEM IV based on the absorbed dose distributions. The resulting RBE-weighted dose distributions were quantitatively compared to assess the clinical impact of LEM IV relative to LEM I in the target volume.LEM IV predicts 20-30 Gy (RBE) increased maximum doses as compared to LEM I, while minimum doses are decreased by 2-5 Gy (RBE). Population-based mean and median doses deviated by less than 2 Gy (RBE) between both models.LEM I and LEM IV-based RBE-weighted doses in the target volume may be significantly different. Replacing the applied model in patient treatments may therefore lead to local over- or underdosages in the tumor. If LEM IV is to be tested clinically, comparisons of the RBE-weighted dose distributions of both models are required for the individual patients to assess whether the LEM IV-plan would also be acceptable and prescribed dose as well as clinical outcome data have to be carefully reassessed.
%F PUB:(DE-HGF)16
%9 Journal Article
%$ pmid:31522880
%R 10.1016/j.radonc.2019.08.006
%U https://inrepo02.dkfz.de/record/144835