Presenter of 1 Presentation
A NOVEL X-RAY SOURCE FOR MICROBEAM AND FLASH RADIOTHERAPY: NUMERICAL SIMULATIONS SHOW THE FEASIBILITY OF THE PRECLINICAL PROTOTYPE
Abstract
Background and Aims
Microbeam radiotherapy (MRT) and FLASH can widen the therapeutic window in radiotherapy. For x-ray MRT and FLASH, most research was performed at synchrotrons that are, however, unsuitable for clinical application. A promising compact source for hospitals is the line-focus x-ray tube (LFxT). We present simulations for a preclinical LFxT prototype that we are currently constructing.
Methods
To examine the dose distribution, we performed Monte Carlo simulations in TOPAS of an electron beam (300 keV, 90 kW) hitting a target made of tungsten. The phase space from electron accelerator simulations exhibited a full width at half maximum of 0.05 x 20 mm2. The produced photons traveled through a model of a custom-made, divergent multi-slit collimator (tungsten) into a water phantom. With finite element methods in COMSOL, we simulated the temperature increase at the focal spot.
Results
The microbeam dose distribution showed a divergent peak-valley profile with a peak-to-valley dose ratio of 23 and a peak dose rate of 10 Gy/s in 15 mm water depth, 200 mm from the target. The temperature increase at the focal spot was 480 K when the target surface moved at 200 m/s. Due to the narrow and fast beam, the main heat dissipation mechanism was heat capacity, contrary to heat conduction for conventional x-ray tubes.
Conclusions
Our simulations showed that the LFxT prototype produces a microbeam dose distribution suitable for preclinical MRT research. The LFxT utilizes the heat capacity limit in which the source can be scaled to a more powerful clinical source for concurrent MRT and FLASH.
Author Of 1 Presentation
A NOVEL X-RAY SOURCE FOR MICROBEAM AND FLASH RADIOTHERAPY: NUMERICAL SIMULATIONS SHOW THE FEASIBILITY OF THE PRECLINICAL PROTOTYPE
Abstract
Background and Aims
Microbeam radiotherapy (MRT) and FLASH can widen the therapeutic window in radiotherapy. For x-ray MRT and FLASH, most research was performed at synchrotrons that are, however, unsuitable for clinical application. A promising compact source for hospitals is the line-focus x-ray tube (LFxT). We present simulations for a preclinical LFxT prototype that we are currently constructing.
Methods
To examine the dose distribution, we performed Monte Carlo simulations in TOPAS of an electron beam (300 keV, 90 kW) hitting a target made of tungsten. The phase space from electron accelerator simulations exhibited a full width at half maximum of 0.05 x 20 mm2. The produced photons traveled through a model of a custom-made, divergent multi-slit collimator (tungsten) into a water phantom. With finite element methods in COMSOL, we simulated the temperature increase at the focal spot.
Results
The microbeam dose distribution showed a divergent peak-valley profile with a peak-to-valley dose ratio of 23 and a peak dose rate of 10 Gy/s in 15 mm water depth, 200 mm from the target. The temperature increase at the focal spot was 480 K when the target surface moved at 200 m/s. Due to the narrow and fast beam, the main heat dissipation mechanism was heat capacity, contrary to heat conduction for conventional x-ray tubes.
Conclusions
Our simulations showed that the LFxT prototype produces a microbeam dose distribution suitable for preclinical MRT research. The LFxT utilizes the heat capacity limit in which the source can be scaled to a more powerful clinical source for concurrent MRT and FLASH.