RVU target in academics?

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Is there any comparative clinical data which shows MRI-adapted therapy leads to improved outcomes compared with non-adaptive IMRT and IGRT? Without that data it's hard for me to justify the increased cost.

Not that I'm aware of, but it's younger than proton therapy is by quite a bit (especially with adaptive planning on the fly at the machine), and we know the state of comparative clinical data for new technologies. Hope those doing it are studying it prospectively
 
Is there any comparative clinical data which shows MRI-adapted therapy leads to improved outcomes compared with non-adaptive IMRT and IGRT? Without that data it's hard for me to justify the increased cost.

Is there any comparative data for any image guided radiation modality showing improved outcomes?

I'm being tounge and cheek here, but it's the truth. Can we bring up CBCT vs. kV or MV trials? Heck, where is proton vs. photon for that matter (we have a little now and it's NEGATIVE)?

My take on Ethos is that it's fine for stuff you can see clearly with a CBCT. That's a lot more limited than MRI-guided RT. Varian could have brought out online adaptive radiotherapy a long time ago with their CBCTs, and they're only doing it now to compete with MRI adaptive.
 
If soft-tissue based IGRT is better than bone-based IGRT, then perhaps we can make the assumption that soft-tissue based IGRT is better than none?

I certainly agree that academia has done a terrible job investigating new technologies over the last 15 years.
 
Is there any comparative data for any image guided radiation modality showing improved outcomes?

I'm being tounge and cheek here, but it's the truth. Can we bring up CBCT vs. kV or MV trials? Heck, where is proton vs. photon for that matter (we have a little now and it's NEGATIVE)?

My take on Ethos is that it's fine for stuff you can see clearly with a CBCT. That's a lot more limited than MRI-guided RT. Varian could have brought out online adaptive radiotherapy a long time ago with their CBCTs, and they're only doing it now to compete with MRI adaptive.
The treatments rad oncs are giving now versus 15 years ago have significantly improved treating physicians’ attitudes about the quality of their given care. The treatments med oncs are giving now versus 15 years ago have significantly kept more patients alive for longer time periods. Zing!
 
If soft-tissue based IGRT is better than bone-based IGRT, then perhaps we can make the assumption that soft-tissue based IGRT is better than none?

I certainly agree that academia has done a terrible job investigating new technologies over the last 15 years.

There is some data out there. Mostly retrospective like you linked. I've written some stuff on this topic of lack of image guided radiotherapy evidence and regulation, and tried to get it in at ASTRO or red journal and had it bounced very quickly every time.

The problem is as follows.

On the med onc side:

1. Pharma companies MUST provide phase 3 randomized trial evidence for a significant outcome before their drug can be approved for an indication.

2. To do this, pharma companies must do large trials, often paid for by pharma to academic centers.

3. Thus, medical oncology treatments have very strong evidence.

On the rad onc (and surgery) side:

1. Device manufacturers only have to state that their device is "substantially equivalent" to a "predicate" device that came before it for approval. They submit safety and feasibility data only, not enhanced effectiveness data. It will be approved for use generally anywhere in the body.

2. Device manufacturers therefore provide very little funding for comparative research. It's actually in their interest not to fund these trials, because what if they're negative? It's very difficult to get money or interest to run these sorts of trials.

3. The devices are then marketed as a way to draw patients. Look at this new toy, it has this bell and/or whistle, and we believe it's better for X reason. Institutions that purchase them to draw patients then have to use them to make money. Therefore the incentive to test the device is totally lost because if you find it is inferior, you lose a lot of money. Even the idea of throwing half your patients on a competing device is not ideal. Even if you ignore the finances, getting patients to come to your center for the new toy and then putting them on the old toy is difficult because patients will refuse. This is the same problem with proton vs. photon, and I'm impressed they managed to even accrue the now negative lung study. I haven't seen a similar trial yet for MR-IGRT. Maybe one of these days in one of the most obvious indications like locally advanced pancreas, possibly after the SMART trial finishes?
 
Is there any comparative clinical data which shows MRI-adapted therapy leads to improved outcomes compared with non-adaptive IMRT and IGRT? Without that data it's hard for me to justify the increased cost.
Hell no. But there is some groundbreaking work going on here outside of pancreas. The UCLA experience of adaptive mri guided radiation for stage I nsclc is going to be a real paradigm changer for this field. It’s really what Thomas Kuhn had in mind.
Cost can be justified by daily planning charges?
 
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Can y'all enlighten a little. Play a prediction game... what are some guesses (ie state a "power"/1-β for a hypothesis in one of these hypothetical trials) for a MR-linac vs best-other trial, if trials were done. For Stage I lung, for pancreas, etc. What "paradigm" we lookin' to change? But I got a spoiler alert because I have seen a few things. If enough people start doing MR guided RT, there will be a rule that comes out limiting planning charges. And in the meantime, hey, why can't a center WITHOUT MR guidance do super-frequent replans too? "Well blah blah and blah thus blah. Blah. That's why. Don't be stupid." It's a slippery, and totally opinionated, slope to say why this can/can't happen.
 
Hell no. But there is some groundbreaking work going on here outside of pancreas. The UCLA experience of adaptive mri guided radiation for stage I nsclc is going to be a real paradigm changer for this field. It’s really what Thomas Kuhn had in mind.
Cost can be justified by daily planning charges?

Why? Not trying to be obtuse, it's just that my stage I NSCLC patients do very well with SBRT with CBCT, with very little in the way of short- or long-term toxicity.
 
Why? Not trying to be obtuse, it's just that my stage I NSCLC patients do very well with SBRT with CBCT, with very little in the way of short- or long-term toxicity.

Basically, any intervention should either: 1) lower toxicity or 2) improve efficacy.

So, lower toxicity would be by decreasing PTV, which is not very big anyway (5mm or less is typically). Can't see MRI helping all that much. It's not like it's going to shrink a lot during treatment. Sometimes, I see it get a little bigger...

Higher efficacy would require a higher dose or some radiosensitization - I don't see how MRI helps with that.
 
So, lower [stage I NSCLC] toxicity would be by decreasing PTV, which is not very big anyway (5mm or less is typically). Can't see MRI helping all that much. It's not like it's going to shrink a lot during treatment. Sometimes, I see it get a little bigger...
A toxicity trial of MR-guidance vs regular IG-IMRT would be tough. I tried plugging in some numbers using MISSILE's (bad trial!) ~20% toxicity rate as a baseline. (FWIW if I had that toxicity rate I'd never do lung SBRT but that's another story.) I'm guessing we need a ~1000 patient trial to see a ~25% actuarial reduction in toxicity. One-thousand-patient-or-more treatment toxicity comparison trials in rad onc... rare as hen's teeth. Can only think of old MRC seminoma trials being comparable in scope. But anyway, a trial is doable. Let's do it.
 
3. The devices are then marketed as a way to draw patients. Look at this new toy, it has this bell and/or whistle, and we believe it's better for X reason. Institutions that purchase them to draw patients then have to use them to make money. Therefore the incentive to test the device is totally lost because if you find it is inferior, you lose a lot of money. Even the idea of throwing half your patients on a competing device is not ideal. Even if you ignore the finances, getting patients to come to your center for the new toy and then putting them on the old toy is difficult because patients will refuse. This is the same problem with proton vs. photon, and I'm impressed they managed to even accrue the now negative lung study. I haven't seen a similar trial yet for MR-IGRT. Maybe one of these days in one of the most obvious indications like locally advanced pancreas, possibly after the SMART trial finishes?

I think this is where academics have lost the way. Everyone just wants to use the latest and greatest but doesn't want to actually have to do academic things and ensure that there is some evaluation of patients who are getting the cutting edge thing. MRI linac is still, mostly, a research machine. I think every single patient being treated on a research machine should be enrolled in a prospective registry to allow for research.

If a patient who is eligible for NSABP-B51 comes in and tells me they don't want to enroll on the trial they just don't want to get PMRT and they want me to tell them that it's OK, I tell them I can't do that. I can enroll them on the trial and give them a 50% chance of omitting radiation.

The concept of MRI-guidance for lung SBRT never made ANY sense to me, as CBCT guidance with minimal ITV margins and use of breath hold or gating for high motion really doesn't seem like a huge issue.

MRI-guidance for prostate to allow for much tighter margins at interfaces and for cervical seem to be reasonable options.
 
I think this is where academics have lost the way. Everyone just wants to use the latest and greatest but doesn't want to actually have to do academic things and ensure that there is some evaluation of patients who are getting the cutting edge thing. MRI linac is still, mostly, a research machine. I think every single patient being treated on a research machine should be enrolled in a prospective registry to allow for research.

If a patient who is eligible for NSABP-B51 comes in and tells me they don't want to enroll on the trial they just don't want to get PMRT and they want me to tell them that it's OK, I tell them I can't do that. I can enroll them on the trial and give them a 50% chance of omitting radiation.

The concept of MRI-guidance for lung SBRT never made ANY sense to me, as CBCT guidance with minimal ITV margins and use of breath hold or gating for high motion really doesn't seem like a huge issue.

MRI-guidance for prostate to allow for much tighter margins at interfaces and for cervical seem to be reasonable options.
It’s just that prostate does fine with almost no toxicity anyway. It can already be planned with mri and sib boost to mri lesion. Hell, put in spacer if you want. I used calypso in past which in some ways Is ultimate daily guidance and was very unimpressed.

In terms of cervical, the ebrt part really does not have much room for improvement or mitigation of side effects.
Mri guided brachy makes sense especially if you can also use interstitial when Needed.
 
Why? Not trying to be obtuse, it's just that my stage I NSCLC patients do very well with SBRT with CBCT, with very little in the way of short- or long-term toxicity.


Agree. The idea of MR guidance for lung is purely academic. I don’t fault those doing it for academic purposes but that’s all it is. We all know that.
 
In cervical cancer, we don't chase the tumor. We electively treat (almost always): upper vagina, uterus, parametria, nodes and allow some margin expansion into rectum and bladder. Thus value proposition of adaptive re-planning is uncertain.

That's literally the point of adaptive planning, to be able to account for that without the massive margins (that would otherwise be necessary) on a daily basis.
 
Sorry if I missed it in this thread, but as soon as you can't bill for a new plan daily on the MRI linac (or adaptive CBCT based linac) it becomes a huge person-hour/cost sink unless you're at a huge center and have tons of other linacs and plenty of staff/physics support.

Even if APM doesn't go through or effect MRI linacs in our cancer center network (~9 total linacs) we just didn't see it as a viable option for us with HUGE downside risk.

If you believe the spaceOAR P3 data there is essentially zero clinically significant rectal toxicity. Even in in the new PACE B abstract we're seeing very little GI toxicity. how can you improve upon that with an MRI or protons? Hard to do.

I agree strongly that it's a bell and whistle to get patients in the door, but I don't think it moves the needle with the exception of maybe pancreas or liver cases. Cervix is reasonable as well but I think with a good CBCT and IMRT they do quite well.
 
In cervical cancer, we don't chase the tumor. We electively treat (almost always): upper vagina, uterus, parametria, nodes and allow some margin expansion into rectum and bladder. Thus value proposition of adaptive re-planning is uncertain.

Right but what if we didn't have to allow margin expansion into rectum and bladder? What if we could do a 2mm margin around the cervix/parametria and monitor it with MRI-guidance?

We allow expansion into rectum and bladder b/c even with full/empty bladder scans you have to consider some non-random motion beyond the ITV that is created.

I'm not saying it's night and day and that MRI-Linac is going to become anything resembling a standard of care, but I wouldn't be surprised if there is some potential improvements in toxicity.

It’s just that prostate does fine with almost no toxicity anyway. It can already be planned with mri and sib boost to mri lesion. Hell, put in spacer if you want. I used calypso in past which in some ways Is ultimate daily guidance and was very unimpressed.

In terms of cervical, the ebrt part really does not have much room for improvement or mitigation of side effects.
Mri guided brachy makes sense especially if you can also use interstitial when Needed.

If we're doing fine with no toxicity then it's time to escalate the dose again on a national level. IMRT and IGRT let us go, as a country, from 70-80 (conventionally fx). Time to go higher again to the whole gland (unless the sib boost to MRI-region pans out as being valuable)

MRI guided brachy doesn't require MRI-guided linac as it's something we routinely do at my institution, but yes, it is much more accurate contouring and delineation than CT-based brachy is.
 
Right but what if we didn't have to allow margin expansion into rectum and bladder? What if we could do a 2mm margin around the cervix/parametria and monitor it with MRI-guidance?

We allow expansion into rectum and bladder b/c even with full/empty bladder scans you have to consider some non-random motion beyond the ITV that is created.

I'm not saying it's night and day and that MRI-Linac is going to become anything resembling a standard of care, but I wouldn't be surprised if there is some potential improvements in toxicity.



If we're doing fine with no toxicity then it's time to escalate the dose again on a national level. IMRT and IGRT let us go, as a country, from 70-80 (conventionally fx). Time to go higher again to the whole gland (unless the sib boost to MRI-region pans out as being valuable)

MRI guided brachy doesn't require MRI-guided linac as it's something we routinely do at my institution, but yes, it is much more accurate contouring and delineation than CT-based brachy is.
Would really not surprise me if 10 yrs Immuno integrated into therapy for cervical cancer and we are thinking abt dose de esca
 
I'm not arguing re: MR-based contouring and dose calculations for cervix IMRT.
I'm saying, a proper upfront plan already accounts for majority of intra- and interfraction erro. It is due to the need to cover adjacent areas at risk for subclinical disease spread.
Yes, some people evaluate minimizing A-P margin expansions by using some form of "adaptation" (e.g. plan of the day concept).

Right but what if we didn't have to allow margin expansion into rectum and bladder? What if we could do a 2mm margin around the cervix/parametria and monitor it with MRI-guidance?

We allow expansion into rectum and bladder b/c even with full/empty bladder scans you have to consider some non-random motion beyond the ITV that is created.

I'm not saying it's night and day and that MRI-Linac is going to become anything resembling a standard of care, but I wouldn't be surprised if there is some potential improvements in toxicity.



If we're doing fine with no toxicity then it's time to escalate the dose again on a national level. IMRT and IGRT let us go, as a country, from 70-80 (conventionally fx). Time to go higher again to the whole gland (unless the sib boost to MRI-region pans out as being valuable)

MRI guided brachy doesn't require MRI-guided linac as it's something we routinely do at my institution, but yes, it is much more accurate contouring and delineation than CT-based brachy is.
 
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I'm not arguing re: MR-based contouring and dose calculations for cervix IMRT.
I'm saying, a proper upfront plan already accounts for majority of intra- and interfraction erro. It is due to the need to cover adjacent areas at risk for subclinical disease spread.
Yes, some people evaluate minimizing A-P margin expansions by using some form of "adaptation" (e.g. plan of the day concept).

As someone that uses this a good bit, it’s not as helpful as you might think for reducing margins. For pelvic tumors a major source of intrafraction motion is bladder filling. Theoretically you can use very tight margins and adapt if the bladder filling isn’t quite right. But by the time you re-run the plan guess what? You may be battling more filling issues.

In my opinion it is a research machine. I bet toxicity for pelvic tumors may eventually prove to be better but it will take YEARS to show (if ever) since we are talking about very small signals at best.

Dose escalation? Maybe. For things like unresectable/borderline pancreas that you want to get a BED > 100, the real strength isn’t the small margins, it’s the ability to change the plan pre-delivery if your OARs consistently differ from your initial plan at the time of sim. How many of you would feel comfortable taking celiac disease to 75 Gy with standard IGRT (assuming your institution participated in appropriate trials)? Even things like this are honestly going to be pretty limited in scope.

Cost is an issue. If you needed treatment and you could pick between MR or KV imaging you would probably pick MR for a lot of disease sites on first principle. But should payers be expected to foot the bill for the extra costs at this point? Like I said above, the similarities with protons abound. Protons shouldn’t be a dirty word but the reality is their utilization exploded with almost no proven benefit and they still haven’t proven to do much of anything better. We should find a home for things before they proliferate to the masses.
 
Has anybody experienced turf war with urology and/or imaging regarding doing spaceOAR and fidicuals in clinic?

Before I got here, prostates were cookbook, and everybody got the same fractiation, margins, and daily CBCTs.

I started sending people to the urologist for transrectal fiducial placement. Unfortunately I'm noticing a lot of fiducials NOT in the prostate.

I am trying to do spaceOAR and fidicual placement myself in the clinic and it is creating a giant ----storm. Mostly from the admin side with imaging admins throwing a fit they there is an imaging device in my clinic, department manager not wanting me to do procedures in clinic, and urologist wanting the ultrasound so they can do spaceOAR.

Suggestions on how to approach this? Just give up and let the urologist do it? Note that they wouldn't be doing spaceOAR at all if I hadn't brought it up, and my contract is salary with an RVU bonus that I will never meet, so I'm signing up to do this extra work (which reimburses well) for free -- feel like I would have to re-negotiate.
 
Suggestions on how to approach this? Just give up and let the urologist do it?
Yeah. Or go to a place that allows you to be a doctor to your patients. I've been both places. Where you are now: check yourself before you absolutely drive crazy yourself.

If you needed treatment and you could pick between MR or KV imaging you would probably pick MR for a lot of disease sites on first principle.
Prediction: one day we will be doing nuclear electric resonance imaging instead of MRI. In theory it will give us very accurate chemical analyses from inside tumors and do other neat things too like map voxels thermally with thousandths of degree precision. And there will be zero magnetic fields so we can do it on everyone regardless of metal in body, pacemakers, etc.
 
Has anybody experienced turf war with urology and/or imaging regarding doing spaceOAR and fidicuals in clinic?

Before I got here, prostates were cookbook, and everybody got the same fractiation, margins, and daily CBCTs.

I started sending people to the urologist for transrectal fiducial placement. Unfortunately I'm noticing a lot of fiducials NOT in the prostate.

I am trying to do spaceOAR and fidicual placement myself in the clinic and it is creating a giant ----storm. Mostly from the admin side with imaging admins throwing a fit they there is an imaging device in my clinic, department manager not wanting me to do procedures in clinic, and urologist wanting the ultrasound so they can do spaceOAR.

Suggestions on how to approach this? Just give up and let the urologist do it? Note that they wouldn't be doing spaceOAR at all if I hadn't brought it up, and my contract is salary with an RVU bonus that I will never meet, so I'm signing up to do this extra work (which reimburses well) for free -- feel like I would have to re-negotiate.

Imaging device? Meaning an US probe? If Urology is willing to do it I would just let them to avoid the **** show. Or be involved in it so they don't jack it up (since you said they're jacking up fiducial placement) but let them bill for it.

If Urology balks or doesn't have availability, then would tell them that I'm going to do it when you can't. Gotta play nice in the sandbox as the referral chain catfish. Unless you think there is no chance of them directing prostate cancer patients away from you (depends on potential competition in your region), this probably isn't the hill to die on.
 
On salary and politically need to be in good standing with urologists. Do you want them making fuss when inevitably patient admitted with prostatitis/sepsis from placement? Whole point of space oar is a kickback to urology as far as I am concerned. It has close to 0 medical benefit and 100% grade 2 toxicity (as far as I am concerned it’s very placement needs to be counted as grade 2!
 
On salary and politically need to be in good standing with urologists. Do you want them making fuss when inevitably patient admitted with prostatitis/sepsis from placement? Whole point of space oar is a kickback to urology as far as I am concerned. It has close to 0 medical benefit and 100% grade 2 toxicity (as far as I am concerned it’s very placement needs to be counted as grade 2!

Do you think spacer placement is more toxic than fiducial placement? I say that mostly tongue and cheek because I have met a surprising number of people that didn’t see fiducials as necessary but are magically on board with SpaceOR.

In all seriousness it’s too soon to tell if it helps. It won’t do anything for acute toxicity. Anyone thinking it will is not thinking critically. Dosimetrically it can significantly improve your high-dose (>V70) rectal volumes which no doubt correlate most strongly with late toxicity. But, as you have appropriately stated above, most guys do pretty well regardless so it’s very far from a guarantee this will translate into a clinical benefit (at least one that is measurable). Gosh, this sounds a lot like the discussion surrounding protons and MR-guided RT. Could be better for X,Y,Z dosimetric reason but we just are not sure. At the end of the day, it blows my mind the things insurers won’t cover that are data-driven but then they pay handsomely for this kind of stuff.
 
On salary and politically need to be in good standing with urologists. Do you want them making fuss when inevitably patient admitted with prostatitis/sepsis from placement? Whole point of space oar is a kickback to urology as far as I am concerned. It has close to 0 medical benefit and 100% grade 2 toxicity (as far as I am concerned it’s very placement needs to be counted as grade 2!
SpaceOAR can be placed transperineally with much lower risk of sepsis compared to transrectal. Many urologists moving to transperineal biopsy to mitigate sepsis risk.
 
SpaceOAR can be placed transperineally with much lower risk of sepsis compared to transrectal. Many urologists moving to transperineal biopsy to mitigate sepsis risk.
Point is if you do procedure and urology not on board and pt is admitted through er a few days later, urology is going to be called and they will make your life difficult.
 
Not even sure how spaceoar can be done via transrectal approach....

One of our urologists said he used to place them transrectally at his old job. I can see how it would be done, but I think it would be a lot harder to get a nice long sup-inf distrubition of the gel. I would imagine you would just get a blob at one spot, which would still have some mass effect on rectum above and below. But maybe I'm wrong.
 
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