SBRT OAR constraints for oral boards?
Started by Krukenberg
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just pick and know it. only ones worth knowing are cord, V20 lung, bowel, esophagus, PBT, plexus mostly. i would use 0813 for lung, other protocols for relevant (liver rtof protocol for liver/bowel numbers for an HCC/LIVER SBRT for example)
if you decide to talk about prostate sbrt or spine, then yeah have stuff in your back pocket for those as well.
if you decide to talk about prostate sbrt or spine, then yeah have stuff in your back pocket for those as well.
Even though Timmerman's were "educated guesses", they have stood the test of time. I think many of us have them drilled into our souls.
I would guess, at least for the next few years, no one can really say you're "wrong" for using either. HyTEC is, by Timmerman's own admission, "better", but until and unless the ABR decides to release a statement about "ABR-sanctioned constraints", I can't imagine you would fail for using the Timmerman constraints (which I will probably fall back on myself).
It would be great if the ABR took official stances on things when fundamental parts of our practices are changing. This is a good example, the AJCC 9th edition coming out piecemeal is another, there are many other small examples.
Even for clinical writtens this came up. I don't want the ABR to do a no-knock raid on my house with this, so keeping things vague - I think many of us who took clinical writtens over the last couple years saw the question about options for definitive NSCLC treatment. There were multiple "correct"/"reasonable" options (especially if you read the ASCO lung guidelines just published).
What was the point of that question? Who wrote it, and what were they looking for? Why is this a black-box process? Will one examiner "fail" you for using Timmerman constraints, and another examiner will be OK with it?
ABR, in the background: "Don't worry, Angoff!"
I would guess, at least for the next few years, no one can really say you're "wrong" for using either. HyTEC is, by Timmerman's own admission, "better", but until and unless the ABR decides to release a statement about "ABR-sanctioned constraints", I can't imagine you would fail for using the Timmerman constraints (which I will probably fall back on myself).
It would be great if the ABR took official stances on things when fundamental parts of our practices are changing. This is a good example, the AJCC 9th edition coming out piecemeal is another, there are many other small examples.
Even for clinical writtens this came up. I don't want the ABR to do a no-knock raid on my house with this, so keeping things vague - I think many of us who took clinical writtens over the last couple years saw the question about options for definitive NSCLC treatment. There were multiple "correct"/"reasonable" options (especially if you read the ASCO lung guidelines just published).
What was the point of that question? Who wrote it, and what were they looking for? Why is this a black-box process? Will one examiner "fail" you for using Timmerman constraints, and another examiner will be OK with it?
ABR, in the background: "Don't worry, Angoff!"
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NCCN has constraints for lung. I would just use those.
Whatever you use, know where it came from. NCCN, Timmerman, BR001…it’s not like one of them is the right answer. Just pick one and go with it. If you give a reasonable answer it is very unlikely they will ask any follow up but if they do, where did you get that number is probably the most likely question you will get. Other than what if you can’t meet that constraint.
Tbh, I think just bringing up the trials is good enough. Don't say anything dumb, but saying you'd refer to one of the sbrt trials is acceptable. Just know constraints for the most important stuff, which in my mind are the max doses for brainstem and cord. Acknowledging that central airways and even the aorta have constraints, which you would confirm, won't get you failed, and thats the goal.
Aorta?!?!
"ESE, what're you limiting great vessels to"
"105% of RX"
"Ok say you get a plan back from Dosi with 130% in the great vessels"
"lol I don't care blow it up next question"
"ESE, what're you limiting great vessels to"
"105% of RX"
"Ok say you get a plan back from Dosi with 130% in the great vessels"
"lol I don't care blow it up next question"
Agree… no one will ever ding you on boards for agreeing with NCCN guidelines. In practice, those constraints are… eh.
The answer is, "I'll search until I find a constraint that suits my plan." That's the same approach to all the research discussed in the "dare you to reply" thread.
Why do you not like NCCN lung constraints?
Long, long ago, in the beforetime - I put together plan evaluation sheets with constraints for myself. There are just...so many options.
When you are able to easily find 8 different, well-established constraints for say, the rectum in a prostate case - it very much begins to feel like a "choose your own adventure" game.
I know what "they" want us to say and will happily oblige but - "I'll search until I find a constraint that suits my plan" is the answer with the most truth.
It's hard to avoid falling into therapeutic nihilism if you go down the constraints rabbit hole too deeply.
Yuck, just looked at em. All max dose constraints. Those constraints will at least allow you to not blame yourself when a patient's aorta explodes. As long as you never look for d1cc, d10cc constraints, etc. I'd take that out of there if i were the NCCN.
edit: pretty much every lung sbrt really requires 1 normal tissue be constrained, possibly with several constraints. It's always near just one thing, and if it's not, you probably shouldn't be doing sbrt.
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They are not internally consistent. For example, look at the esophagus.
According to constraints, 8 Gy x 4 exceeds constraints… but 8 Gy x 5 = no problem. In real life, 55 Gy in 5 fx is a pretty bonkers point max for esophagus.
It’s a patchwork of protocols. It’s fine for the boards,
