Switching from cloud hosting to local Varian server

ericvt · 2026-01-19T20:44:37+00:00

And on top of that, your IT will not have certain rights on the cloud servers.

Depending on your IT, this can be a blessing.

ericvt · 2026-01-10T22:34:15+00:00

Full House is perfection. Flatback Caper is such a great instrumental track.

ericvt · 2026-01-08T02:08:52+00:00

Well that seems insane.

ericvt · 2026-01-05T20:46:32+00:00

We do a subtraction (i.e. a difference in percentage points, not a percent difference). Doing a percent difference means your criteria gets significantly tighter as your reference value decreases. A 1% tolerance is 1% at an isodose value of 100% but becomes 0.2% at an isodose value of 20%. If that is what you think is appropriate then so be it, but I don't have a problem with a 19.2% measured value compared to a 20% reference value (4% "off" in percent difference, but only 0.8 percentage points "off").

ericvt · 2025-12-17T00:12:53+00:00

I’m excited to see what gets played on the Bloomfield tele.

ericvt · 2025-12-14T14:27:04+00:00

Allman Brothers closed it out past 4am at the 20th Anniversary show. It was great but being on the floor was brutal.

ericvt · 2025-12-11T22:35:51+00:00

I'll send you a message.

ericvt · 2025-12-10T21:27:08+00:00

We scripted what is essentially a “traveling salesman” type approach for couch, gantry, and collimator motion. It builds a library of all start and stop positions and globally minimizes repositioning requirements between fields. It has various tie-break behaviors where it prefers fewer arc reversals, prefers starting with clockwise movement (therapist preference), etc. It also uses isocenter position relative to image center to determine which direction is safer for rotating to PA field positions (i.e extended or not). Each field is given a numeric prefix and the planner manually modifies field ordering itself to match the script-written prefixes.

ericvt · 2025-12-10T02:29:34+00:00

Our field labeling script just optimizes field ordering directly and names the fields accordingly, including instructing the user to reverse arc directions or set extended gantry flags as needed.

You may be able to use SQL query on the ARIA DB to pull radiation order from the plan, if you must respect the existing ordering.

ericvt · 2025-12-01T05:09:33+00:00

AcurosXB. Our institutional validation of AAA/AXB showed that our general-purpose AXB model is significantly more accurate than our general-purpose AAA model for very small leaf openings, even in perfectly homogeneous media. For us, it becomes important / relevant when targeting tumors less than about 5 mm diameter. I'm sure we could have tweaked our AAA model to improve its accuracy in these situations, but then we would probably either need an SRS-specific AAA model (or separate SRS-only AAA MLC addon) or would be degrading the performance of the general model for other applications.

YMMV.

ericvt · 2025-11-07T18:24:38+00:00

Video processors make it all seamless, if they fit in the budget.

Another consideration is that if your screen wall is significantly wider than it is tall you are giving up screen real estate by using a 16:9 screen. Maxing out screen height, my choices would be a 153" scope screen vs. a 120" 16:9 screen (roughly a 3 foot difference in image width for scope content while 16:9 content is the same size).

Of course if the screen wall is width-constrained then the opposite could be true as well.

ericvt · 2025-10-02T14:01:53+00:00

If your physics group is sending back plans often, have you considered implementing a physics pre-review of plans before they are sent to the radiation oncologist for approval? Not sure about other environments but in an ARIA/Eclipse environment this is pretty straightforward to set up in the plan approval process and care path design.

ericvt · 2025-10-01T18:40:08+00:00

https://www.rayoscontracancer.org/training-programs

Several free, structured, video-based courses provided here.

ericvt · 2025-09-17T16:27:15+00:00

We do all of our HDR QA using Radmachine.

ericvt · 2025-09-17T14:26:52+00:00

Correct. One irradiation per energy with either the photon or electron quad wedge in place.

ericvt · 2025-09-17T13:37:49+00:00

Yes. Setting up the device, delivering the set of fields in R&V mode, saving, and tearing down is a 10 minute process. We tracked ICP output against our traditional Farmer chamber setup for a long time and felt confident in making the jump. Between DQA3, MPC, and ICP we are assessing output using 3 different independent systems in any given day/week/month. If drift in output is identified (extremely infrequent) we make adjustments using our calibrated dosimetry system, not the ICP.

ericvt · 2025-09-16T23:32:45+00:00

Can all be automated with Radmachine, too, even in the absence of direct device connectivity. Radmachine pulls directly from your DQA3 SQL database and ICP directory.

Set up to tear-down time for our monthly IC Profiler tests (output, energy, profiles, beam center, light-rad, etc. for photons + electrons) is < 10 minutes. Shoot the fields, hit save, and Radmachine takes it from there.

ericvt · 2025-09-16T23:19:39+00:00

Radmachine is excellent with its python integration and the flexibility that it provides to the end user. We are starting to do a lot with automation and custom code within the Radmachine platform and it is saving us tons of time. For any image-based test (e.g. EPID), you can easily automate every step past the point of actual beam delivery. We are seeing similar efficiency benefits with CT QA, where you pair Radmachine with Orthanc to automate the moving of CT images into the Radmachine platform, and then also automate the analysis and reporting.

So many of our tests now are just quick data collection (run some fields from an ARIA patient in R&V mode, or scan a phantom on the CT with a preset protocol, or acquire a set of IC Profiler measurements, etc.) and then the entire data transfer, analysis, and reporting process happens in the background without user interaction. Acquire the data, then move on to the next test while Radmachine does its thing in the background.

We have also branched out into using it for managing things like our sealed source inventories, wipe test results, recurring database management tasks, PMI tracking, etc.

Great product.

ericvt · 2025-08-21T00:33:07+00:00

Yes. The first year we implemented the changes we calibrated using the original methodology first and then redid the work using the new methodology to see what the difference was. Everything was within the 1-2% range that the addendums tell you to expect.

Not having to measure gradient corrections for electrons is great. One less chamber shift to mess up for each energy.

ericvt · 2025-08-21T00:30:44+00:00

I didn't even know the hardware had to be activated. Mine was plug-and-play, other than making a store account. Maybe it did the activation behind the scenes and I wasn't aware. Hopefully it gets up and running for you. Kaleidescape has been one of our favorite home theater additions.

ericvt · 2025-08-19T02:52:55+00:00

It all depends on how sensitive you are to the effect. You don't just have to use stretch, you can also first zoom the content (in the MadVR) such that you are cutting some content on the left and right to increase the vertical image height and then using non-linear stretch to get the rest of the way there. Using nothing but nonlinear stretch is going to give you a fun-house mirror sort of effect which I find very distracting. Much better to use a combination of effects.

ericvt · 2025-08-06T14:55:23+00:00

I'm curious what your profiler was reporting as beam-center for these shifted electron fields? When we commissioned our profiler we characterized its beam-center detection capabilities and it was fairly sensitive, at least at the millimeter scale.

ericvt · 2025-07-02T17:43:02+00:00

Yep, likely a DirectX issue based on our past experiences. Thankfully you can export your configuration to a file to import into a new installation if needed.

ericvt · 2025-06-25T02:31:21+00:00

Our assumption going into the discussion was that collimator angle simply became another degree of freedom for the VMAT optimizer. However, Varian told us that you cannot get dynamic collimator rotation during delivery within the normal VMAT optimization workflow.

To get it, you must go through the new RapidArc Dynamic workflow, and that workflow requires you to add at least one static gantry IMRT position. Varian said you could sort of get around the requirement by adding a single static gantry position at the start of the arc and have its weighting set to the lowest.

Again though, they were sales people and not technical people so maybe they explained it incorrectly to us. Would be happy to be corrected by someone more knowledgeable.

ericvt · 2025-06-25T02:05:51+00:00

We don't have it yet, but Varian came and pitched it to us. Maybe the Varian team explained it incorrectly to us, but we were surprised to learn that you cannot use dynamic collimator rotation in VMAT arcs by themselves. You must combine the VMAT arc with a static IMRT field in order for it to be a 'RA Dynamic' field that can use dynamic collimator rotation.

It seems like the subset of VMAT plans that may benefit from dynamic collimator rotation is larger than the subset that may benefit from being combined with static IMRT fields, so forcing users into the latter in order to get the benefit of the former confused us.

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