Proton Calorimetry/Meetings/2017/04/28: Difference between revisions

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=== Relevant References ===
=== Relevant References ===
(Laurent, make these into proper DOI links in the style of the first)


* Gottschalk B, E W Cascio, J Daartz, and M S Wagner (2015), [https://doi.org/10.1088/0031-9155/60/14/5627 "On the nuclear halo of a proton pencil beam stopping in water"] Physics in Medicine and Biology '''60'''(14) p.5627.
* Gottschalk B, E W Cascio, J Daartz, and M S Wagner (2015), [https://doi.org/10.1088/0031-9155/60/14/5627 "On the nuclear halo of a proton pencil beam stopping in water"] Physics in Medicine and Biology '''60'''(14) p.5627.

Revision as of 10:20, 12 May 2017

Minutes for UCL Proton Dose Build-up Meeting, 28th April 2017 (Skype)

Present

Richard Amos, Adam Gibson, Jenny Griffiths, Simon Jolly, Laurent Kelleter

We have graph of amount of buildup against energy. Can we get a graph of depth of buildup (perhaps depth at which buildup reaches 95% of expected value) or something? For electron and proton buildup? That’s probably reanalysing existing Bragg peaks.

Verify the results showing the effect of air — it’s surprising that air appears to have no effect. Perhaps try 1m of air, and look for heavy particles hitting skin as a result of interactions with air.

Energy spectrum of electrons/secondary protons as a function of depth for 60, 150, 230 MeV beams. Identify particles which are generated. Find LET for each type. Give contribution to dose from each particle.

Can we predict RBE given LET? Literature is unclear, but probably for electrons and protons, not for other particles without a lot of work.

For clinical relevance, can we calculate:

  • Buildup for SOBP (say choose 50% modulation at different energies and plot buildup against maximum energy of SOBP)
  • Buildup for SOBP (say choose a single energy and for different modulations from 0-100% or depth, plot graph of buildup v % modulation)

(By modulation, I mean the depth of the SOBP as a percentage of the total depth, ie a SOBP giving maximum dose at depths from 5cm to 10cm would have a modulation of 50%)

Relevant References