= LhARA radiobiology; meeting: 27Nov25; 14:00 BST =

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

Attended: EM, JMcG, CW, DA, AFr, TP, AG, MB, MH, JP, RW, CD

== Meeting Notes == 

1. Minutes and actions:

2. Laser: RW \\
- RW: Explanation of the laser problem and the fix
 - That problem seems permanently fixed.

3. RCF: AFR, DA, CD \\
- Calibration
 - Rotation Issue
 - Rotating the films in the scanner can cause a ~30% change to the mean dose in a particular case. More generally causes a substantial difference.
 - Can combat by rotating the films each time we scan and always selecting the orientation that gives the highest mean pixel count
- Calculating Dose per Shot, Variation and Dose delivered to Cells
 - From RCF, average dose per shot of 0.61±0.25Gy (More data to be analysed)
 - Hard to spot a variation day to day
 - Variation in one showed a change after 8 films had been irradiated. Need to analyse the shots to get a better understanding of what this is
  - Robbie's suggestion is a defocussing laser spot effect
- Flatness and Uniformity of Dose
 - Average CV: 15.1±2.5%
 - Average Flatness in X: 26.4±5.5%
 - Average Flatness in Y: 29.6±4.7%
 - Beam is too non-uniform still
- Sim comparison
 - CV: 17%
 - Moving the Copper closer would bring CV down to 9% and the mean dose would also fall by 45%
- [raw-attachment:EarlyRCFAnalysis.pptx Slides]

4. Bio: EM, JP \\
 - Dry run seeding density test has worked: [raw-attachment:Dry Run and Shot Doses.pptx Slides]
 - Marie/Rosh are going to check colonies on Friday/Monday and make executive decision on staining days
 - Test the temperature of the incubator, as it seems too warm
 - Incubator water dried out, Rosh has refilled (some indication the plates were drying out ~50% - check how much as only 3ml was added. Could top up with fresh media)

 - Josie sent cell pellets over to Marie/Rosh - will comets be performed? Concern is the “time point” due to the time spent on ice post-IR

 - Wait for staining (& analysis?) of current clonogenics before irradiating more cells
 - If no survival in the control plates is seen, procedure needs evaluating as dry run was ok
 - Issues for running cells next week: Cells/Mylar dishes/lids need to be taken from Birmingham  - discussions regarding specific ideal days and people availability are needed
 - Next run - do comparable experiments with Marie/Rosh and the X-ray source and possibly add RCF to base of the cell dish.
  - Discussion of faster cell analysis techniques such as western blot 
  - Use IF to get an idea of hotspots in the cell dish?

5. Future: \\
- Current Problems:
 - Clear Communication of Requirements
 - RCF to Dose Procedure
  - Alfredo and Diaza are piecing together a protocol document to standardise how we complete this procedure
  - The rotation issue is taken into account
  - Diaza in favour of scanning at lower resolution to speed it up
 - Uniformity not good enough
  - Place the Copper scatterer closer
  - Results need to analysed
 - Shot-to-shot variation
  - Include a piece of RCF in front of the cells (Ideally delaminated but not possible to calibrate before the next visit)
   - Need to sim what the LET would be for our energy range into the cells with the RCF in place
  - Longer-term investigate an on-beam diagnostic
  - Another option is to find a correlation between the RCF mean dose and one of the laser diagnostics that the team already gathers

- Discussion of when to use the rollover days 
 - Plan to use Wednesday, Thursday and Friday next week
 - If good, then use the 3 days to do more cell irradiations
  - Emma will send the dishes up tomorrow 
 - If not work on more beam diagnostics and improving it to complete cell irradiations, tackling either uniformity or shot-to-shot variation

- IPAC abstract submission?
 - No takers and a belief that we should wait until we have a slam dunk result
 - Note: LhARA will have a general submission that will mention PoPLaR
- Book a longer discussion to analyse all the results and define a plan for the future
 - Not discussed

6. DoNM 
- 11th Dec

7. AoB
- Congratulations Dr Melia!!!
- [raw-attachment:Emma_Congrats.pptx pic]

=== Summary of actions required ===
== Short-Term ==
 - **MB**: Evaluate the cells
 - **EM**: Send the cell dishes to SCAPA if required and decide on the shot plan
 - **CD, RW, EM, CW ...**: Plan what to run if cells not required. Lay out a clear aim for the rollover days.
 - **CD, TP**: Evaluate LET in the cells with the RCF in front
 - **CD, AFr**: Complete analysis of RCF with Error Calculation
 - **AFr, DA**: Write out RCF procedure document
 - **TP**: Test orientation of calibration RCF in scanner at Birmingham
 - **CD**: Send shot results to Robbie to help find the cause of variation after 8 films irradiated

== Long-Term ==
 - **ALL**: Organise a longer meeting discussion post rollover days
 - **RW, CD**: Study correlation between laser diagnostics and mean dose
 - **EM, JMcG**: Write up summary of PoPLaR Phase 2
 - **KL**: Investigate other on-beam diagnostics
 - **CD, JMcG**: Investigate how to achieve uniformity without scatterer in place





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