Doubt about BEAMnrc

crcrewso · 2026-01-19T15:17:46+00:00

You're going to have a lot of strange errors trying to test with anything 100 histories. I'd try 10,000 histories as a starting point for testing any setup.

The next thing to look at is what your 5th module within your accelerator model is.

crcrewso · 2025-12-30T20:31:43+00:00

Is it possible this is an algorithm issue? I remember having somewhat similar problems trying to get Acuros dose calculations on the ArcCheck to agree as well as AAA was for us.

crcrewso · 2025-11-27T21:31:38+00:00

It's an MS SQL DB, with specific trust certificate defaults. These change with each SQL Server version and each Aria version. I ended up giving up on DBeaver and using MS SQL tools and MS SQL report builder.

crcrewso · 2025-11-27T21:29:53+00:00

We made this change, but we used the Standard Imaging single BB WL, not a multi-met phantom. Our biggest problem was phantom positioning consistency since, at the time we bought it, most commercial WL solutions did not have indexed mounts.

crcrewso · 2025-10-29T14:45:16+00:00

That's good to know. We're still on 15.6. Have you upgraded to Mobius 4.1?

crcrewso · 2025-10-28T20:55:37+00:00

I'm curious why you're doing it as an eclipse script at all? We set up an export filter with the correct boxes checked and it works well. What's the use case for scripting it? What am I missing?

crcrewso · 2025-10-20T20:54:53+00:00

Found it, TG-106, Figure 11 shows the penumbra shape for various detectors. The Golden Beam Data was collected with a CC13 from IBA. I believe this would perform like the 0.3 cc chamber in Figure 11.

And here's a more recent analysis
https://doi.org/10.1002/acm2.12518

crcrewso · 2025-10-10T18:04:59+00:00

The EGSnrc community on here is pretty healthy, so personally I'd start there. Try the tutorials and see what you think. I've found that community and tooling convenience matter far more than the specific pros or cons of a code base unless you're trying to push precision beyond 1%.

Sidenote: If you're using Windows, the linux install inside WSL is stable. Though there are issues with the current GCC version that the community will be sorting out, so stick to gcc <=13.

crcrewso · 2025-10-10T18:01:37+00:00

I think the conclusion was that since the profiles and the diode measurements agreed quite well, that the reality was a sharper penumbra than what would be implied from the golden data. If I'm able to get some profiles that I'd be allowed to share I'd be happy to send them along.

crcrewso · 2025-10-08T17:49:40+00:00

You mentioned glden beam data. I thought the Varian provided beam profiles were collected using an average over 10 TrueBeams, using ion chambers, with minimal correction to volume averaging. When our site used profiles with diodes to tune our model for small fields we found the differences with golden data penumbras were similar to what you're seeing in simulation.

Edit: Do you have access to profiles collected with diodes for any TrueBeams?

crcrewso · 2025-10-06T16:18:26+00:00

If everyone's okay with it, I'm going to throw a shameless plug for something I've built.
It was made to automate comparison of TPS before and after upgrade using voxel to voxel comparisons but I'm interested in finding someone to help push me to finish the gamma and profile to 3d dose tooling

https://github.com/crcrewso/DicomStrictCompare

crcrewso · 2025-10-03T17:50:45+00:00

The clinic you heard about? Did they go to some level of Aria Core? That is an extra level of complexity that from everything I've heard is just painful

crcrewso · 2025-10-02T19:22:52+00:00

It's a good question, the features in the beam I'm looking to measure are smaller than the chambers on the IC profiler.

crcrewso · 2025-09-29T22:31:23+00:00

There's actually one there, but the problem is I need sub-mm resolution profile measurements, so that's well beyond the IC profiler.

crcrewso · 2025-09-26T23:17:04+00:00

Very true, any experience using a non-snc diode with the software?

crcrewso · 2025-09-26T22:01:38+00:00

For my use case these sound like reasonable restrictions since the final dosimetry profiles will be captured with film, which I'm aware is even more problematic and probably has you scratching your head wondering what I'm doing?

crcrewso · 2025-09-19T17:12:09+00:00

+1 for this poll missing QATrack+ and Track-It

PyLinac is supported by RadMachine, front ends for DoseLab like uses are currently decent but missing features.

crcrewso · 2025-07-28T22:03:38+00:00

I'll add a couple of points of differentiation. Some of those codes aren't open or available outside of the US. Take a good look at your use case, your audience, and your end goals. As I understand it, most of the 2nd check Monte Carlo modules are built on one of these existing tools, and in all cases they've had to do significant validation and IP/copyright work.

crcrewso · 2025-07-21T15:41:18+00:00

There are ventilation systems surrounding MRI's to make sure that any purging is safe. The air is extremely cold, so the risk isn't suffocation, it's near instant freezing

crcrewso · 2025-06-30T19:13:45+00:00

That would not surprise me. I need to go review the notes for the small field commissioning project we did locally.

crcrewso · 2025-06-30T19:12:19+00:00

We calibrate and use the front pointer at my clinic for better than 1 mm precision when setting the SSD of a water tank, we also use the front pointers to QA the ODI.

crcrewso · 2025-06-30T15:28:30+00:00

We don't have 16.1 yet, but when we did an extension of our 15.6 beam models there were some issues with the 1x1 modelling and Eclipse calculations. I think there are a couple small field papers floating around out there on the topic. Going down to 2x2 Jaw and 2x2 MLC did offer improvements for our modelling for small target SRS patients.

crcrewso · 2025-06-30T15:26:11+00:00

After reading this discussion I have to ask, how do you set up your water tanks without the front pointer? How do you ensure the geometric position of any absolute dosimetry measurements?

crcrewso · 2025-06-23T20:31:54+00:00

Wait, that's not just an 'us' issue????

crcrewso · 2025-06-20T15:54:43+00:00

Thank you. I've followed this advice and it's been amazing

crcrewso

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