Optimizing Isocenter Accuracy in ExacTrac Dynamic ® : Daily Verification and Quality Assurance for Reliable Patient Positioning
Year: 2026
Type: article
Abstract: Introduction Advances in teleradiotherapy, such as SRS and SBRT, have improved treatment by delivering higher doses in fewer sessions, reducing duration, and sparing healthy tissue. These techniques require precise patient positioning, achieved through systems like SGRT (surface tracking) and IGRT (X-ray imaging). The ExacTrac Dynamic system (Brainlab AG, Germany) combines both, offering submillimetric accuracy for cranial radiotherapy. This study evaluates its quality assurance (QA) protocols, focusing on calibration, accuracy, and clinical performance. Background and Purpose SRS and SBRT allow targeted treatment with minimal margins, reducing complications. Precise alignment is essential, particularly for cranial cases. The study assesses the QA processes of the ExacTrac Dynamic system and evaluates its accuracy and reliability. Results Daily logs revealed differences between Surface Tracking and X-ray imaging. X-ray was more reliable, especially for longitudinal translational deviations, while Surface Tracking was affected by thermal artifacts. Rotational deviations remained within tolerance, with the largest shifts in yaw. Histogram analysis showed skewed distributions, underscoring the importance of combining both methods and regular QA. Conclusion Regular QA and recalibration of the ExacTrac Dynamic system are essential to address discrepancies between SGRT and X-ray methods. X-ray offers greater precision, while Surface Tracking is prone to environmental artifacts. Combining SGRT and IGRT ensures accuracy but requires consistent QA to maintain treatment precision.
Language: English
Subfield: Radiation
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: diamond
OpenAlex ID: W7138900717