ESTRO 2021 Abstract Book
S1489
ESTRO 2021
Conclusion In this feasibility study, we have showed that it is possible to achieve hypofractionated (3 Gy(RBE)/field) proton therapy within a single breath-hold for a small lung case. To this goal, both beam-on time and dead time were improved, using new beam optics in the delivery and spot reduced and energy layer reduction optimization in the planning. This is a very promising option to treat moving targets. We will extend the investigation of the use of these techniques on different large (300-500 ml) moving tumor cases to deliver the treatment within a single breath-hold (5-10 seconds). PO-1763 Comparison of intrafractional optical surface/thermal and X-ray imaging for cranial radiotherapy P. Freislederer 1 , D. Reitz 1 , V. da Silva Mendes 1 , G. Landry 1 , M. Reiner 1 , M. Niyazi 1 , C. Belka 1 , S. Corradini 1 1 University Hospital, LMU Munich, Department of Radiation Oncology, Munich, Germany Purpose or Objective Intrafractional motion can occur during cranial radiation therapy and could lead to significant deviations between planned and delivered dose, especially with open face masks. The novel ExacTrac Dynamic (Brainlab AG, Germany) allows continuous monitoring of the patient surface inside an open thermoplastic mask using optical and thermal imaging information, while simultaneously relying on orthogonal X-ray imaging to provide information on the positioning of the bony anatomy. We evaluated the differences between the surface/thermal data of structures visible in the opening of the thermoplastic mask and the corresponding X- ray internal bony anatomy registration during cranial radiotherapy (see figure
Made with FlippingBook Learn more on our blog