ESTRO 2024 - Abstract Book

S4726

Physics - Optimisation, algorithms and applications for ion beam treatment planning

ESTR0 2024

beam line data and geometry and including per-field aperture and range-compensator. The dosimetric correspondence is good and GMC recomputation of the plan dose is on the order of 5 sec. We demonstrate the quality of the original dosimetry in comparison to pencil-beam scanning and VMAT and in a study for a particular unique case of treatment of a chordoma in a 19yo treated in 1997 and surviving to this date. At this point, we are ready to commence recomputation of the various cohorts of patients based on their use in various studies to augment and presumably improve on the dosimetry of those studies. The use of GMC allows us to also add biological effect data in terms of local dose-average LET and estimates of RBE variations.

Conclusion:

The simple conclusion is that only now, after 40 years, photons are “close” to protons and, conversely, how incomparable protons were than. Proton therapy proved the axiom of radiotherapy: higher dose (not per se from protons), quality and localization improves cure.The original patient dosimetry is remarkably accurate which is attributable to the low scatter of protons and 3D mechanical-only manipulation of the proton pristine peak to achieve a flat lateral and in-depth field dosimetry. This allows even a simple model to provide precise results. The large and well documented and studied patient cohorts offers a unique opportunity for re-analysis through improved dosimetry and the addition of biological effect parameters. This work is a tribute to the HCL and MGH teams that realized this unique clinical program.

Keywords: data mining, proton dosimetry, fixed beam

3187

Digital Poster

The applied radiobiological effectiveness model influences tumor control when treating with ions

Judith Besuglow 1,2,3 , Thomas Tessonnier 4,1 , Stewart Mein 5,6,3 , Tanja Eichkorn 7,8 , Thomas Haberer 9 , Klaus Herfarth 7,8 , Amir Abdollahi 1,10 , Jürgen Debus 7,8,11 , Andrea Mairani 4,1,12 1 German Cancer Research Center (DKFZ), National Center for Tumour Diseases (NCT) and Heidelberg University Hospital (UKHD), Clinical Cooperation Unit Translational Radiation Oncology, Heidelberg, Germany. 2 Heidelberg University, Department of Physics and Astronomy, Heidelberg, Germany. 3 Heidelberg University Hospital (UKHD) and Heidelberg Faculty of Medicine (MFHD), Division of Molecular and Translational Radiation Oncology, Heidelberg Ion Beam Therapy Center (HIT), Heidelberg, Germany. 4 Heidelberg Ion-Beam Therapy Center (HIT), Medical Physics, Heidelberg, Germany. 5 German Cancer Research Center (DKFZ), National Center for Tumour Diseases (NCT) and Heidelberg University Hospital (UKHD), Clinical Coopertation Unit Translational Radiation Oncology, Heidelberg, Germany. 6 Perelman School of Medicine, University of Pennsylvania, Department of Radiation Oncology, Philadelphia, USA. 7 Heidelberg Ion-Beam Therapy Center (HIT), Heidelberg University Hospital (UKHD), Department of Radiation Oncology, Heidelberg, Germany. 8 National Center for Tumour Diseases (NCT), Radiation Oncology, Heidelberg, Germany. 9 Heidelberg Ion-Beam Therapy Center (HIT), Physics, Heidelberg, Germany. 10 Heidelberg University Hospital (UKHD) and Heidelberg Faculty of Medicine (MFHD), Division of Molecular and Translational Radiation Oncology, Heidelberg Faculty of Medicine (MFHD), Heidelberg, Germany. 11 German Cancer Research Center (DKFZ), Clinical