Speaker
Description
With cancer rates increasing, the need for effective treatments is urgent. Very High Energy Electron (VHEE) and FLASH therapies could revolutionise cancer treatment, offering effective cancer cell killing while reducing induced side effects and reducing treatment delivery time. CLARA beamline upgrades make VHEE beam production at conventional (CONV) and ultra-high dose rates (UHDR) possible for the first time in the UK. Here, we present first findings from CLARA-VHEE studies, including beam parameterisation, dosimetry and cancer cell irradiation.
The first campaign focused on beam parameterisation, establishing the dose rates achievable with CLARA to validate its FLASH capabilities. This was achieved through irradiating a patient-equivalent water phantom containing EBT4 radiochromic film. The dose and resulting dose rate of the beam phantom was determined and percentage-depth dose curves obtained based on the transverse beam path. Lateral beam spread was analysed to determine scattering within the phantom. Irradiations were repeated for 100-250 MeV electron beams, with bunch charge and frequency varied to deliver CONV and UHDR beams. CONV dose rates were measured at 3.6±0.02 Gy/s and UHDR at 94.4±1.2 Gy/s – comfortably exceeding the generally-accepted FLASH threshold.
Lung adenocarcinoma cells were irradiated to determine cellular response to CONV and FLASH VHEE irradiation. Samples were irradiated across 0-8 Gy at 250 MeV, with cell survival and DNA damage quantified. Cellular response to CONV VHEE irradiation at 250 MeV was comparable with 154 MeV VHEE results (ARES, DESY). Preliminary data indicates that A549 survival rate decreases more rapidly following VHEE-FLASH, indicating a potential improvement in cell-killing capabilities for VHEE-FLASH irradiation.
First irradiation studies have shown the capability of CLARA to produce VHEE-FLASH beams, with cell irradiations at these energies and dose rates being a UK first. Improvements in laboratory infrastructure at CLARA will allow for more ambitious biological experiments, paving the way for potential clinical implementation.
| Presenting Author | Kristina Small |
|---|---|
| Is the Presenting Author a PhD Student or Early Career Scientist ? | No |
| Area of research | Applications of accelerators |