Presenter of 1 Presentation
FEASIBILITY OF ULTRAHIGH AND CONVENTIONAL DOSE RATE IN VITRO STUDIES ON A BENCHTOP X-RAY SYSTEM
Abstract
Background and Aims
The goal of this work was to demonstrate the feasibility of in vitro studies with multicellular spheroids using a conventional 80kVp x-ray tube capable of both ultrahigh (UHDR, >40Gy/s) and conventional (0.1Gy/s) dose rate delivery.
Methods
In order to achieve UHDR delivery with <1s irradiation times, a motorized rotating shutter system was designed and installed on a conventional MXR22/160 x-ray tube. 80kVp X-ray dose was measured using a plastic scintillation detector (PSD) system, Hyperscint. Signal from lead-loaded (0.5-5%Pb) and polystyrene (BCF-10) 3-mm long PSDs with a 3-mm cap placed at 2.2 cm from the focal spot was measured and validated with Monte Carlo (MC) simulations. To achieve conventional irradiations, measurements at extended source-to-detector distances (SDD) of 10-20cm were conducted. Dose rate to a 500-µm diameter spheroid was calculated (with 120kVp x-rays).
Results
Measurements with lead-loaded and BCF-10 PSDs agreed with simulations and showed maximum dose rates of 61.1 and 9.0Gy/s, respectively. Dose was linear with shutter speeds ranging from 1-200ms (R2>0.999 for all probes). The inverse square law dose rate fall-off was confirmed by PSD measurements and conventional dose rates were achieved by reducing the tube current and extending SDD to 6.7cm for the BCF-10 PSD (which mimics soft tissue). The maximum dose rate to the cell spheroid placed in the shutter was determined to be 243.1Gy/s.
Conclusions
Ultrahigh and conventional dose rates were attainable using a conventional x-ray tube equipped with a shutter system by varying tube current and SDD. This cost-effective x-ray source provides convenient access to UHDR in vitro studies.
Author Of 1 Presentation
FEASIBILITY OF ULTRAHIGH AND CONVENTIONAL DOSE RATE IN VITRO STUDIES ON A BENCHTOP X-RAY SYSTEM
Abstract
Background and Aims
The goal of this work was to demonstrate the feasibility of in vitro studies with multicellular spheroids using a conventional 80kVp x-ray tube capable of both ultrahigh (UHDR, >40Gy/s) and conventional (0.1Gy/s) dose rate delivery.
Methods
In order to achieve UHDR delivery with <1s irradiation times, a motorized rotating shutter system was designed and installed on a conventional MXR22/160 x-ray tube. 80kVp X-ray dose was measured using a plastic scintillation detector (PSD) system, Hyperscint. Signal from lead-loaded (0.5-5%Pb) and polystyrene (BCF-10) 3-mm long PSDs with a 3-mm cap placed at 2.2 cm from the focal spot was measured and validated with Monte Carlo (MC) simulations. To achieve conventional irradiations, measurements at extended source-to-detector distances (SDD) of 10-20cm were conducted. Dose rate to a 500-µm diameter spheroid was calculated (with 120kVp x-rays).
Results
Measurements with lead-loaded and BCF-10 PSDs agreed with simulations and showed maximum dose rates of 61.1 and 9.0Gy/s, respectively. Dose was linear with shutter speeds ranging from 1-200ms (R2>0.999 for all probes). The inverse square law dose rate fall-off was confirmed by PSD measurements and conventional dose rates were achieved by reducing the tube current and extending SDD to 6.7cm for the BCF-10 PSD (which mimics soft tissue). The maximum dose rate to the cell spheroid placed in the shutter was determined to be 243.1Gy/s.
Conclusions
Ultrahigh and conventional dose rates were attainable using a conventional x-ray tube equipped with a shutter system by varying tube current and SDD. This cost-effective x-ray source provides convenient access to UHDR in vitro studies.