ESTRO 2024 - Abstract Book

S3637

Physics - Dose prediction, optimisation and applications of photon and electron planning

ESTRO 2024

landmarks, quantification of dose mapping uncertainties should be considered to further increase confidence in these estimates.

Keywords: dose accumulation, pancreas, DIR

References:

1. Tsien C, Kim JP, Mignano JE, De Mol Van Otterloo SR, Christodouleas JP, Blezer ELA, et al. The MOMENTUM Study: An International Registry for the Evidence-Based Introduction of MR-Guided Adaptive Therapy. Frontiers in Oncology | www.frontiersin.org [Internet]. 2020;1:1328. Available from: www.frontiersin.org 2. Brock KK, Mutic S, McNutt TR, Li H, Kessler ML. Use of image registration and fusion algorithms and techniques in radiotherapy: Report of the AAPM Radiation Therapy Committee Task Group No. 132: Report. Med Phys. 2017 Jul 1;44(7):e43–76.

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Digital Poster

Dosimetric comparison of liver SBRT treatments with conventional linear accelerator and CyberKnife

Enikő Koszta 1 , Szilvia Gazdag-Hegyesi 1,2 , Ádám Gáldi 1,3 , Tibor Major 1,4 , Zoltán Takácsi-Nagy 1,4 , Csilla Pesznyák 1,5 , Gábor Stelczer 1,5 1 National Institute of Oncology, Center of Radiotherapy, Budapest, Hungary. 2 Budapest University of Technology and Economics, Doctoral School of Physical Sciences, Budapest, Hungary. 3 Semmelweis University, Doctoral School of Theoretical and Translational Medicine, Budapest, Hungary. 4 Semmelweis University, Department of Oncology, Budapest, Hungary. 5 Budapest University of Technology and Economics, Institute of Nuclear Techniques, Budapest, Hungary

Purpose/Objective:

Stereotactic body radiation therapy (SBRT) is an accurate and precise treatment method with steep dose gradient and high dose conformity. The aim of our study is to perform a dosimetric analysis of liver SBRT performed with conventional linear accelerator (LINAC) and CyberKnife (CK).

Material/Methods:

Clinically approved irradiation plans have been analysed for LINAC and CK for eight and ten patients, respectively. With LINAC 4D computed tomography (CT) scans were created in 7 equally separated breathing phases from a full respiratory cycle. The gross tumour volume (GTV) was delineated on each phase and accumulated on the average CT. Moreover, for the determination of GTV, contrast-enhanced CT and/or MR scans were obtained. The clinical target volume (CTV) was determined by extending the accumulated GTV with 2-5 mm, not exceeding the liver. An additional margin of 2-8 mm was then applied to create the planning target volume (PTV), depending on the patient's tumour movement and its location. For treatment planning, VMAT irradiation technique and 10MV