ESTRO 2024 - Abstract Book

S3819

Physics - Image acquisition and processing

ESTRO 2024

the 5 patients, no impact was found on the target volume coverage while 1% of deviation was found for the D2% of the spinal cord.

Conclusion:

Our study highlights the impact of residual geometric distortions on stereotactic radiotherapy treatments. They become a critical issue for structures located at more than 6 cm from the magnet isocenter and can induce dosimetric impact on target volume coverage and on doses to organs at risk. The 3D distortion correction map should be included in the treatment planning process. In addition to the residual distortion, one can also considered the patient specific susceptibility-induced distortions.

Keywords: 3D MRI distortion map, stereotactic treatments

References:

[1] C. K. Glide-Hurst et al., « Task group 284 report: magnetic resonance imaging simulation in radiotherapy: considerations for clinical implementation, optimization, and quality assurance », Med. Phys., vol. 48, no 7, p. e636-e670, juill. 2021, doi: 10.1002/mp.14695.

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Digital Poster

Evaluation of the Direct Density Algorithm for Metal Artifact Reduction.

Javier Sánchez-Esperón 1 , Isabela Gaztelu-Blanco 2 , Sara Estrella-Máquez 2 , Fernando Picón-García 1 , Montserrat Baeza Trujillo 1 , Florencio Javier Luis-Simón 1 1 University Hospital Virgen del Rocío, Department of Medical Radiation Physics, Seville, Spain. 2 University Hospital Virgen del Rocío, Department of Radiation Oncology, Seville, Spain

Purpose/Objective:

Introducing the Direct Density algorithm in the presence of metal should be done with care, as the same calibration curve is used for different tube voltages in a CT. The obtained images seem to show a reduction in metal artifacts. The algorithm uses a bone image in its calculations [1]. The metal is identified as bone in the bone image, which can affect subsequent calculations made by the algorithm. Therefore, it is not trivial that the algorithm can reduce metal artifacts. The aim of this study is to quantitatively asses the dosimetric impact of metal using Direct Density algorithm.

Material/Methods: