Speaker
Description
Background
FLASH radiotherapy is an emerging technique that delivers radiation at ultra high dose rates (UHDR) and has demonstrated promising preclinical results, achieving effective tumor control while reducing normal tissue toxicity. The aim of this study was to develop a quality assurance (QA) system able to characterize the electron beam of a newly commissioned FLASHKNiFE (TheryQ) accelerator. The characterization focused on spatial and temporal dose rate, pulse length and structure, irradiation time, field composition, and out of field dose. Accurate determination of these parameters at UHDR is challenging due to potential detector saturation.
Methods
Measurements were performed for a 9 MeV electron beam with the detector positioned out of field at a distance of 320 cm, aligned toward the distal end of the applicator. The QA system consist of an AdvaPIX Timepix3 detector with a 100 µm silicon sensor, a 1 cm diameter lead collimator connected to a newly developed SW module for beam monitoring data processing incorporated into the TraX Engine. The data driven acquisition mode eliminated the need for manual trigger manipulation or external synchronization with the accelerator. Accelerator input parameters—frequency, pulse length, and pulse number—were varied to obtain benchmark measurements.
Results
The beam monitoring SW module enables nearly real time data processing and visualization of all measured parameters including: pulse width and structure, pulse repetition frequency and number of pulses. Experimental data were compared with the accelerator’s Log files, demonstrating an agreement within 2.5% between the two.
Conclusions
The newly developed non-invasive QA system was confirmed to be suitable for quality assurance of the FLASHKNiFE medical accelerator. The results demonstrate the feasibility of a real time monitoring system capable of analyzing UHDR beam characteristics during experiment or patient treatment.
Acknowledge:
This work was supported by project Robotic FLASH radiotherapy: A technical, biological, clinical and societal evaluation. (HERC69)