Related Experiment Videos
Multi-criterial patient positioning based on dose recalculation on scatter-corrected CBCT images
Jan Hofmaier1, Jonas Haehnle2, Christopher Kurz1
1Department of Radiation Oncology, University Hospital, LMU Munich, Munich, Germany; Department of Medical Physics, Faculty of Physics, Ludwig-Maximilians-Universität München, Munich, Germany.
Summary
Dose-guided patient positioning using scatter-corrected cone-beam CT (CBCT) is feasible. This method allows for better control over radiation therapy target coverage and organ-at-risk doses, enhancing treatment precision.
Area of Science:
- Medical Physics
- Radiation Oncology
- Image-guided therapy
Background:
- Cone-beam computed tomography (CBCT) is increasingly used in radiation therapy for patient positioning.
- Accurate dose calculation on CBCT images is challenging due to scatter radiation.
- Dose-guided patient positioning aims to improve treatment accuracy by adapting to daily anatomical changes.
Purpose of the Study:
- To evaluate the feasibility of dose-guided patient positioning using dose recalculation on scatter-corrected CBCT data.
- To assess the potential advantages of this approach compared to conventional positioning methods.
- To investigate the accuracy and clinical utility of dose interpolation for real-time dose assessment.
Main Methods:
- A scatter correction method was applied to enable dose calculations on CBCT images.
- An interactive, multicriteria tool for dose-guided positioning, utilizing interpolated sample doses, was employed.
- The workflow was retrospectively evaluated on 39 CBCT datasets from two head and neck cancer patients.
- Dose-volume histogram (DVH) parameters were compared against rigid image registration-based isocenter corrections.
Main Results:
- Dose interpolation accuracy was sufficient for implementing dose-guided positioning.
- For one patient, mean parotid gland dose was improved in 2 out of 5 fractions, with other parameters maintained.
- For the second patient, mean planning target volume (PTV) coverage improved by 4%, with trade-offs in organ-at-risk (OAR) doses within tolerance.
- The method demonstrated feasibility and potential for improved target coverage and OAR sparing.
Conclusions:
- Dose-guided patient positioning based on scatter-corrected CBCT is feasible in clinical practice.
- This approach offers enhanced control over target coverage and OAR doses during radiation therapy.
- The findings support the integration of advanced image-guided techniques for optimizing radiation treatments.