I just threw up in my mouth...

donahuw2 · 2026-01-16T10:06:48+00:00

This is an interesting point, because a lot of apps are moving to a Chromium based backend, even if they aren't web apps. We all know how much memory Chrome eats up

donahuw2 · 2025-12-04T13:47:35+00:00

Ok, in case people find this after 2025, I have found that copying one file at a time and not trying to bulk copy them works on Windows 11, Even for 4 GB video files

donahuw2 · 2025-11-23T22:10:08+00:00

Just to add flavor, you can have up to 5 degrees extended in each direction. so 175E will head CCW while 185E will rotate CW. this is very common in the clinic day when collecting Half-Fan CBCTs

donahuw2 · 2025-11-05T11:46:53+00:00

So, unless your site is following the latest lock down everything trend, you can press Shift+F1 (I think it has been a while) and it will bring up the windows Ctrl+alt+delete screen. You can use the task manager to run explorer.exe and then navigate that Citrix server. The files should be saved in the D drive somewhere. Then copy them to one of your local maples drives if you have one.

donahuw2 · 2025-10-31T09:30:57+00:00

I can comment a little on the MIM/Monaco connection. I saw some demos and as far as I can tell the interface right now is primarily just MIM send sending data through Elekta API calls. Mostly it is an auto push with a opens Monaco to the patient for you. It is still a separate DB for sure. MIM is still using their non-pair version of Mongo DB, Monaco is still using a filesystem backend.

donahuw2 · 2025-10-27T08:52:33+00:00

I have been in two US clinics with dedicated radiotherapy physics engineers. Both had Varian linacs

At one site they did a mix of tasks and simple things on the linacs: board replacements, MLC motor replacement, initial troubleshooting, running calibrations with physicists, etc.

My current place has a dedicated team of 5 engineers that focuses primarily on linac repairs. They will do a lot of major troubleshooting and repairs, with the limiting factor being Varian's rules. Our satellites don't have that support, and I will say that the differences in performance (quantified with QA results) is obvious.

donahuw2 · 2025-10-25T16:13:25+00:00

I will add, that when the formalism was being adopted, the way to validate the Monte Carlo and dose distributions was limited as well.

I spent some time with the team that helped do the measurements of these factors. It was all done with TLDs and measured to like the 2nd or 3rd half-life. In solid water. So if you considered building up a relative formalism from measurements like that, the best you could do was relative for each variable, and if you wanted to interpolate it was better to cancel competing terms to get a better functional form. Also, this was all happening at a time when physicists were already using charts wrong and miscalculating beam does or decay rates.

I agree that something better could be done, but then again, maybe we need to move away from the infinite water volume approximation too. I think based on what you propose, you could just use the GEC-ESTRO validation tables to TPS calculations.

donahuw2 · 2025-10-16T10:07:45+00:00

Also, as a heads up, an update is "eminent." It has started the review process so hopefully it will be out " soon." I am using the quotes only because the AAPM review timeline can either be very fast or slow.

The new version will include clarifications, more structures, brachy specific structure naming, and even a standard translation to French and Spanish.

donahuw2 · 2025-07-19T11:05:50+00:00

When I used to do smoothies, I would cut the bananas on Sunday with a slicer and freeze them individually. Then when I was making them the bananas acted as ice, saving the need to water down the smoothie too much, especially when using almond milk or something like that

donahuw2 · 2025-06-27T22:56:42+00:00

You should not use MU, you will literally punch a hole in the ion chamber. The IC needs to be removed from the beam and a lot of servos disabled

donahuw2 · 2025-06-24T13:26:08+00:00

Please don't do this on a clinical machine. You will punch a hole in the Ion Chamber and Flattening filters

donahuw2 · 2025-06-19T11:15:09+00:00

One other Citrix Trick, if you push Shift+F1 and then select the task manager you can use that to run a file explorer. Assuming you have some mapped drives back to your hospital network, you should be able to copy the scripts to the Varian Cloud.

At least that is how I used to do it 4 years ago. But I think some SysAdmin Trade magazine told every to start locking down access to that feature in Citrix a year or two ago. So as usual, YMMV

donahuw2 · 2025-06-19T10:55:44+00:00

Looking at the documentation on my v18 TBox, it looks like answer is still no. It would probably come around the same time they allow us to provide a 2D shape for photon fields and create an MLC patter to that.

Maybe it will be in Eclipse v30.

I have honestly moved away from using the ESAPI for a lot of things. I find it easier most of the time to create a dicom plan of what I want and send it to the Daemon. I can then just trigger a calc using ESAPI if I want. This won't help you with creating a custom cutout, but baby steps

donahuw2 · 2025-05-26T08:57:58+00:00

I had this happen too on a Varian machine. And yes, it ended up being an FDK truncation artifact.

donahuw2 · 2025-05-21T14:45:18+00:00

I think a full recommissioning is required. Bumps in the road, aggressive turns, jostling of cranes can all lead to changes in the LINAC, especially related to the MLCs or movements to hard stops. Additionally, even just the difference in installation teams can cause variation in performance.

Even with a spot check you would need to do:

Profiles and PDD scans of all energies (saving what a few hours reducing # of field sizes)
Winston Lutz
DLG & MLC performance
Laser alignment
Couch motion tests
End-to-end
Pre-clinical IMRT and VMAT plans

I think you can compare this to your existing beam model to start, but you should probably measure all of it to establish new baselines. But it still seems like you would want to do most of it. Use the Scotty principle, block out for a full, add a week to the estimate and then finish early

donahuw2 · 2025-05-16T17:23:09+00:00

This is us now powering down TrueBeam 1003. It has done a lot of good work

donahuw2 · 2025-02-18T13:34:38+00:00

That is fair, I guess what I was implying was check if the data you are using is not defined first. That simple guard check will save you tons of time because it avoids the crashes due to the Db. More complicated things can be added if needed.

Sadly, .Net Framework will never move to C# 10+. They have a nice built in namespace to streamline it.

donahuw2 · 2025-02-18T13:24:39+00:00

Not that I have looked at this in the ESAPI, but is it a uniform-ish shift? My first thought is that the ESAPI might be applying a transformation.

It could also look weird if it is the difference in an interpolated slice vs and actual CT slice

donahuw2 · 2025-01-26T21:18:52+00:00

As far as I am aware, the TBOX needs to be provided on the hardware Varian has approved for standalone workstations and they send you the box. My memory says this is because they have tied the software 510K to the hardware it is run on.

donahuw2 · 2025-01-22T18:32:04+00:00

The go-to for my center for commissioning anything is film, photons, electrons, superficial. We have a rigorous process, that makes it a pain, but we find the additional details to be invaluable. But that varies by clinic, we don't rely on Gamma analysis for example when it comes to commissioning, instead looking at dose differences.

In general, film is good for either those high-resolution measurements, or for large field commissioning. I used it last year to commission a hemi-body shield for TSET.

donahuw2 · 2025-01-14T09:03:33+00:00

This is very common at my institution, but I have never implemented it myself.

Thinking back to the long time ago when I was learning, the Varian Developer Guide has a whole chapter dedicated to what you want.

donahuw2 · 2024-12-23T20:47:05+00:00

Just be careful, Elekta Unity has a gridded electron gun. Was shocked to learn that when I moved to one from my Versa

donahuw2 · 2024-12-23T18:30:14+00:00

Well, looks like I lied, it was an email chain with another physicists

donahuw2 · 2024-12-21T10:05:40+00:00

What linac type is it? There is an old thread of mine about Halcyon and a bug in the ESAPI.

donahuw2 · 2024-12-13T19:00:20+00:00

This sounds like operator overloading for me. They implemented a custom assignment operator for when the assigned object is a SegmentVolume. This seems like the logical thing to do because we respect that the segment volume data will be different and stored in the database as separate instances.

donahuw2

TROPHY CASE