LhARA radiobiology; meeting: 23Jul26; 14:00 GMT

ZOOM: ​https://imperial-ac-uk.zoom.us/j/98220889714?pwd=SM90vOF7BKSXoU3mD9q7OwBQo4IVB3.1

Meeting Notes

Attended: KL, CD, JMcG, AG, JB, PP, AFr, AT, BS, CW, DA, GS, JuP, MD, MH, NK, RH, RA, RW

1. Long-term LhARA Biology Plan

• KL: Presentation Slides
  • Radiobiology is a key component throughout the LhARA program
    • Aim for the program to be definitive
    • Must be multi-disciplinary. Have to do the radiobiology but in new ways
    • Multi-national: Need greater expertise
    • Multisource: laser-driven, electrons, X-rays, and gamma-rays for reference sources
    • Multi-messenger: Diverse cell lines, diverse markers (need to integrate automation)
    • Systematic: Same conditions at a variety of sources across borders
    • AI-enabled: Consistent sample handling and irradiation
      • Interpretation: AI as well to develop more on TOPAS and G4DNA
• JMcG: Presentation Slides
  • Long-term vision of a facility that can support: FLASH, SFRT, Advanced Imaging and Beam Monitoring
  • PoPLaR Current Vision:
    • Improve setup and workflow protocols and instrumentation needed
    • Becomes a comparison against X-ray and cyclotron proton beams
    • Measuring: Clonogenics, Comet assays, Fixed IF (immunofluorescence) imaging
  • Live Cell Imaging:
    • Understand underlying mechanisms in real-time
    • Builds on Tony's SFRT work and FLASH comparisons
    • Biggest limitation on previous fixed IF SFRT work was only able to compare different cell samples at each time point.
      • Live cell imaging would help fix this.
• General Discussion
  • Strong agreement that comparison between laser-driven and cyclotron is key.
  • Next vary the beam, looking at FLASH and SFRT
    • Agreement that this needs to focus on particular biological hypotheses
    • Need to understand mechanisms being discussed behind both and what the current hypotheses are
      • Review literature
        • Literature review: Mechanisms, challenges and opportunities for FLASH radiotherapy in cancer Marie-Catherine Vozenin  1   2 , Pierre Montay-Gruel  3   4 , Pelagia Tsoutsou  5   6 , Charles L Limoli  7 DOI: 10.1038/s41568-025-00878-9
      • Invite experts in: Jason et al, Yolanda et al, Dresden group, Maria Catherine at PSI
        • Also, input from Jason, Emma, Marie and Katya (Munich) about what they expect at each stage as the instrumentation and beamline gets better.
      • Identify which hypotheses LhARA is uniquely capable of testing
      • Josie to coordinate
  • Strong agreement to start developing live cell imaging techniques now so when the beamline is ready it is ready.
  • Warning that if we do not see differences at the cell level does not mean there is no difference at the tissue or for whole organisms
  • Strong agreement that dosimetry must be included from the outset

2. Overview of Current SCAPA Plan

• Solutions to the three main problems:
  • Move the scatterer further up the beamline (closer to the laser-target).
  • Use a real-time diagnostic
  • Investigate how long the cells survive and the cause of death
• Additions:
  • Collect more biology results?
• When?:
  • Confirmation: earliest possible beamtime is February, as this is when the tape drive is being put back in.
• More information: ​https://docs.google.com/document/d/1OTARVtxhLRu02S6CLdRDB2QlGvCqDfZ3aWBifjIFs_Q/edit?tab=t.0
• Steps required: Below and at ​https://trello.com/invite/b/67587c515b0c69656ee78b48/ATTIe86f94b24e3e5884e4cb87e5ed3b89ab64321B83/poplar

3. Instrumentation Discussion

• Options:
  • Sparse scintillating fibre arrays in the vacuum chamber
  • Scintillating fibre around the cell dish
  • Lanex around the cell dish
  • Integrated Current Transformers (ICTs)
  • Laser Diagnostics (Backscatter etc)
  • Replace the scatterer with a scintillating sheet
  • (RCF around the cell dish (if desperate))
  • Discussion:
    • Other diagnostics:
      • Should include Liverpool's fluorescence.
        • Colin to contact Narender about implementation
      • Suggestion to use the fast electrons as a diagnostic
      • Nick also has his ToF for future times when we have money
    • Scifi:
      • Test clear fibre in a beam. If it scintillates then can use it in the scifi array. If it doesn't can use it to transport the light out the vacuum chamber from the scifi array
        • Robbie offered to test at ELI. He leaves on the 16th August.
          • Ken and Calvin to send to SCAPA before then (Contact Ewan or Colin since Robbie is USA)
        • If no time can always test at Swansea or Birmingham
    • Lanex:
      • Fear of Lanex quenching at high rep rates but this is more of a concern near the laser target rather than at the cell dish
  • Testing Method:
    • Agreement that we should calibrate with RCF before hand
    • However, also calibrate a batch of RCF that is scanned after a shorter time period (not 24/48 hrs)
      • Use this for continuous calibration of whichever diagnostic is used during cell irradiations

4. BioPrep Discussion

• Spatial Variation: Is a CV of 8% acceptable?
  • Diaza has read a lot of literature that says 5% should be the maximum
  • Need to figure out how to improve the beamline (Move PMQs)
• Cell Control Survival:
  • Need to test how long cells can remain vertical
    • Josie to plan a test
      • Investigate:
        • Vertical or time out of incubator
        • Emma/Jason's HeLa cell line
        • Marie's cell line
    • Also look at evolving a group of cells that can survive the Mylar
  • Can reduce the time taken to conduct the irradiations (and therefore the time the cells are vertical for)
  • Monitor the temperature of the thermostat
• Better instrumentation:
  • Emma and Jason looking at a glass ring setup so that the cells could remain submerged in media
    • Potential to leak...
  • Investigate thicker Mylar as less likely to poke through with pipette
    • Can get up to 1mm Mylar
  • There is an inverted microscope for £250: Openflex 3D printable one with raspberry pi. Could automate counting?
• More results (as well as clonogenics):
  • Comet analyses
    • Agreed to do
  • X-ray comparison on-site
  • IF:
    • Very useful for SFRT
    • Also, provides a potential internal dosimeter: 30 dots = 1Gy
      • Could store two samples and use one as the dosimeter
      • Would have to be consistent with when the cells are fixed and stained
      • Need to test further: Josie to look into this. Discuss with Emma
    • Concern is the labour to check at every timepoint

5. Alternate Beamlines
   • ELI Rejected
     • Waiting for feedback
       • Robbie says they usually give good feedback and much easier to get beamtime on the second try

6. Discussion on Ion-Acoustic Plan
   • Current updates
   • No time

7. DoNM
   • 06/08/26

8. AoB

• Richard: Proton beams at Medical Director Holland PTC. FLASH enabled, and they are actively looking to offer the beam out for experimentation. In Amsterdam. Timeline: Available now but not sure how many other people have started to apply. Write a paragraph about what they wanna do. Did not mention cost.

Summary of actions required

In-Beam Diagnostics

• Unassigned: Acquire a glass sheet
• Unassigned: Get a new RCF batch and calibrate
• TP: Testing delaminating EBT3
• PH: Obtain transparent fibre or an alternative method for light transport
• PH: Obtain a lens for hollow fibre tests
• CD: Simulate energy deposited in transport fibres
• KL, CD, JMcG, PH: Design a system to make full scifi prototypes
• KL, CD, JMcG, PH: Make a full scifi prototype
• KL, CD: Send clear fibre to SCAPA before 16th August (Contact Ewan or Colin since Robbie is USA)
• KL, CD, JMcG, PH: Discuss visit to Birmingham to test SciFi
• RW, CD: Study the correlation between laser diagnostics and mean dose
• Unassigned: Investigate how a phosphor sheet could be incorporated into the design of the cell dish
• CW: Investigate the feasibility of ICTs for our beamline
• MH: Investigate LET detector
• CW: Ask Narender about air fluorescence implementation
• JMcG: Investigate using IF as a dosimeter

Bio Next Steps

• EM, CD, JMcG: Write up technical summary of Phase 2
• EM: Write up a biology plan for a 2 PMQ setup
• Unassigned: Obtain an inverted microscope
• Unassigned: Obtain multi-chamber haemocytometers (Might be able to use Birmingham's)
• Unassigned: Obtain a thermostat for the incubator
• EM: Run controls to examine how long the cells can survive vertically
• JMcG: Plan a test of vertical cell survival using Emma/Jason's HeLa cell line and Marie's cell line
• JMcG: Produce a HeLa colony that can survive on Mylar

Beamline Modelling

• Unassigned: Investigate how to improve the beamline beyond CV=8%
• CD: Examine energy spectra variation
• RW, CD: Source characterisation

Alternate Beamlines

• JMcG: Simulate BELLA
• JMcG: Simulate ELI

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