Project Details
Projekt Print View

Extraction of vector field-based motion signatures from 4D (CB)CT image sequences and correlation with local control of lung and liver metastases after SBRT

Subject Area Epidemiology and Medical Biometry/Statistics
Medical Physics, Biomedical Technology
Term from 2017 to 2024
Project identifier Deutsche Forschungsgemeinschaft (DFG) - Project number 390567362
 
Final Report Year 2024

Final Report Abstract

Respiratory motion represents a challenge in radiotherapy of thoracic and abdominal tumors. To take into account associated uncertainties during radiation planning and therapy, imaging and accurate assessment of tumor motion and motion of organs at risk is required. Corresponding cornerstones of current radiotherapy workflows are 4D computed tomography (4D CT) and 4D cone beam CT (4D CBCT). However, both imaging modalities lead to image artifacts that hamper their clinical application (e.g., target volume definition, non-linear registration-based motion estimation, estimation of the applied dose). Our project aimed to optimize 4D CT and 4D CBCT image acquisition and image quality, image-based extraction of motion information and to better understand the relationship between motion variability, image quality and the most important clinical endpoint: local tumor control. Using deep learning approaches, methods were developed to minimize motion-associated artifacts in 4D CT and 4D CBCT image data as well as errors in registration-based motion field estimation. 4D CT artifacts are mainly caused by motion variability during data acquisition. To tackle this cause directly, a new 4D CT imaging protocol (i4DCT) was developed together with our cooperation partners (Siemens Healthineers). i4DCT adapts the data acquisition in real time to the patient's breathing patterns and leads to a significant artifact reduction compared to conventional 4D CT protocols. This appears even more relevant from a clinical perspective, as a significant correlation was observed between reduced local tumor control and the occurrence of severe artifacts in the 4D CT radiotherapy treatment planning image data. However, it remains to be investigated whether this correlation is causal or whether other aspects are the underlying cause (e.g., differences in breathing patterns during 4D CT imaging and treatment dose application).

Publications

 
 

Additional Information

Textvergrößerung und Kontrastanpassung