Rad Onc Twitter

  • Thread starter Thread starter deleted1002574
  • Start date Start date
This forum made possible through the generous support of SDN members, donors, and sponsors. Thank you.
Let's say the results are real and side effects are less. My issue is what it will do for the cost of healthcare and how are we supposed to give patients the "standard of care" if they can't afford it or can't travel to a proton facility or if insurance just flat out says no? They could just say it's a reasonable alternative for patients but as an option and should not be the preferred treatment.
 
Let's say the results are real and side effects are less. My issue is what it will do for the cost of healthcare and how are we supposed to give patients the "standard of care" if they can't afford it or can't travel to a proton facility or if insurance just flat out says no? They could just say it's a reasonable alternative for patients but as an option and should not be the preferred treatment.
What MDACC and their like will never say, but is undoubtedly true (take a look at the demographics that Palex posted), is that protons are for the rich elite. Either people who are comfortably wealthy with good insurance who can afford to spend a couple of months in Houston or the obscenely rich for whom money is never an object.
 
Let's say the results are real and side effects are less. My issue is what it will do for the cost of healthcare and how are we supposed to give patients the "standard of care" if they can't afford it or can't travel to a proton facility or if insurance just flat out says no? They could just say it's a reasonable alternative for patients but as an option and should not be the preferred treatment.
Just try and offer the protons. Really hype them. Put the patient on a guilt trip to make a proton trip. And then if all that fails, you did the right thing and the burden of feeling like you have mistreated the patient is removed. Let the insurance thing fall on the academic center. (If it’s Medicare, no problemo.) I’m sure if they can’t get protons approved they will send the patient back to you for IMRT.
 
Just try and offer the protons. Really hype them. Put the patient on a guilt trip to make a proton trip. And then if all that fails, you did the right thing and the burden of feeling like you have mistreated the patient is removed. Let the insurance thing fall on the academic center. (If it’s Medicare, no problemo.) I’m sure if they can’t get protons approved they will send the patient back to you for IMRT.
Actually seeing a patient who has a GBM demanding they receive protons. I'm sure we all have had these experiences because they all fed false hopes of a cure with protons and nothing else is acceptable.
 
Just try and offer the protons. Really hype them. Put the patient on a guilt trip to make a proton trip. And then if all that fails, you did the right thing and the burden of feeling like you have mistreated the patient is removed. Let the insurance thing fall on the academic center. (If it’s Medicare, no problemo.) I’m sure if they can’t get protons approved they will send the patient back to you for IMRT.
The centers around here will kidnap my patients even if they were to give IMRT. They use protons as a marketing tool to get them through the door. By the time I see them again, they were already told how much better their Trubeam is compared to mine.
 
A large cancer center just told a patient their right breast radiation was better than mine, so it definitely was worth leaving their hometown and getting a hotel for a few weeks to leave their family with young children. Not even the machine. Just the whole kit n' kaboodle. I would prefer to have been surprised by the news. I am not.
 
A large cancer center just told a patient their right breast radiation was better than mine, so it definitely was worth leaving their hometown and getting a hotel for a few weeks to leave their family with young children. Not even the machine. Just the whole kit n' kaboodle. I would prefer to have been surprised by the news. I am not.
Oh the centers here always get a new set of imaging studies and work up because their radiologists, pathologists, staff, labs and machines are the best!
 
Didnt you hear?? "Local doctors can't keep up"!

A large cancer center just told a patient their right breast radiation was better than mine, so it definitely was worth leaving their hometown and getting a hotel for a few weeks to leave their family with young children. Not even the machine. Just the whole kit n' kaboodle. I would prefer to have been surprised by the news. I am not.
 
I find the trial to be hard to believe too, but are some of you being intentionally obtuse?

The abstracts says "a new standard of care" treatment, not "the new standard of care" treatment. They're not overselling the results in the abstract.
 
Def a fair question to ask and want to avoid piling on. Personally, I would have preferred the below, but maybe we are splitting hairs:

Interpretation
IMPT showed non-inferiority to IMRT for progression-free survival and reduced high-grade toxicity relative to IMRT. Treatment-related and post-progression deaths occurred more frequently with IMRT. IMPT is a standard-of-care treatment option for patients with oropharyngeal cancer.


Theirs:
Interpretation
IMPT showed non-inferiority to IMRT for progression-free survival, improvement in overall survival, similar disease control, and reduced high-grade toxicity relative to IMRT. Treatment-related and post-progression deaths occurred more frequently with IMRT. IMPT is a new standard-of-care treatment option for patients with oropharyngeal cancer.



I find the trial to be hard to believe too, but are some of you being intentionally obtuse?

The abstracts says "a new standard of care" treatment, not "the new standard of care" treatment. They're not overselling the results in the abstract.
 
I find the trial to be hard to believe too, but are some of you being intentionally obtuse?

The abstracts says "a new standard of care" treatment, not "the new standard of care" treatment. They're not overselling the results in the abstract.
I mean we all know what happens next.
 
I mean we all know what happens next.

1765873323976.png


😛 😛 😛
 
Color me skeptical.

Any difference in PFS on that trial is seen after 4 years (curves literally superimposed until then). Yet, progression in OPX cancer occurs within 2 years in 90-95% of patients. OPX cancer almost "never" progresses after 4 years. Yet, there's a flurry of events between 4-5 years in the IMRT group (around the time an interval analysis may be taking place) and after that the groups track exactly together again, never widening over further follow up. Seems........odd.

As-Treated IMRT (171 patients):
raw progression: 14.6% (25/171)
death without progression: 8.1% (14/171)
lost to follow up: 7.0% (12/171)

As-treated IMPT (226 patients)
raw progression: 12.8% (29/226)
death without progression: 5.7% (13/226)
lost to follow up: 2.6% (6/226)

1.8% difference in actual, raw progression. Increased deaths without progression and greater lost to follow-up, points to a less-healthy, less socioeconomically advantaged as-treated IMRT vs IMPT group. Which we always knew.
 
Last edited:
Color me skeptical.

Any difference in PFS on that trial is seen after 4 years (curves literally superimposed until then). Yet, progression in OPX cancer occurs within 2 years in 90-95% of patients. OPX cancer almost "never" progresses after 4 years. Yet, there's a flurry of events between 4-5 years in the IMRT group (around the time an interval analysis may be taking place) and after that the groups track exactly together again, never widening over further follow up. Seems........odd.
Well keep in mind there are two downward ticking events in PFS curves: progression or death. And protons tended to show survival advantage so PFS separation at longer interval could make sense if protons are less murdery than photons. That said divining much from the way the KM curves dance or don’t is bootless mostly.
 
Well keep in mind there are two downward ticking events in PFS curves: progression or death. And protons tended to show survival advantage so PFS separation at longer interval could make sense if protons are less murdery than photons. That said divining much from the way the KM curves dance or don’t is bootless mostly.
Perhaps the protons are indeed less murdery betwixt the 4 and 5-year mark and then similarly murdery once again. Seems unlikely, but possible.

I think non-inferior to IMRT and "a" standard of care is a very reasonable conclusion.
 
Last edited:
My gestalt on all the data is that protons and well-planned IMRT are more or less equivalent. More ORN risk with protons, more lymphopenia and salivary changes with IMRT.

My main issue with the recently-published phase III trial is what I would describe as a dramatically unacceptably high rate of PEG use. I've never see close to those numbers in my practice with IMRT. It takes a lot of physician, nursing, and patient work to avoid a PEG, but the data's pretty clear there's a benefit to avoiding it.
 
My gestalt on all the data is that protons and well-planned IMRT are more or less equivalent. More ORN risk with protons, more lymphopenia and salivary changes with IMRT.

My main issue with the recently-published phase III trial is what I would describe as a dramatically unacceptably high rate of PEG use. I've never see close to those numbers in my practice with IMRT. It takes a lot of physician, nursing, and patient work to avoid a PEG, but the data's pretty clear there's a benefit to avoiding it.
100% agree. Working hard to avoid the PEG makes recovery so much better.
 
  • Like
Reactions: OTN
Perhaps the protons are indeed less murdery betwixt the 4 and 5-year mark and then similarly murdery once again. Seems unlikely, but possible.

I think non-inferior to IMRT and "a" standard of care is a very reasonable conclusion.
This could happen if the proton patients receive adequate palliative (and sometimes even curative) treatment of the recurrence they experienced at 2 years out of primary treatment. Not necessarily because they had protons, but because perhaps as more wealthy patients had better follow-up, access to more salvage treatments and overall supportive services.

These things kept them alive for a few more years. This of course would mostly make sense in the per-protocol treated patients.
 
This could happen if the proton patients receive adequate palliative (and sometimes even curative) treatment of the recurrence they experienced at 2 years out of primary treatment. Not necessarily because they had protons, but because perhaps as more wealthy patients had better follow-up, access to more salvage treatments and overall supportive services.

These things kept them alive for a few more years. This of course would mostly make sense in the per-protocol treated patients.
The initial recurrence would/should have registered as an event at the time it occurred for PFS for those patients though. They'd have been censored as an event prior to death.

The IMRT patients had higher death without progression (murdery-ness of treatment vs. co-morbid health status), and higher censoring due to lost to follow up which accounts for most (almost all) of the difference seen in PFS. At least, looking at the raw stats.
 
The initial recurrence would/should have registered as an event at the time it occurred for PFS for those patients though. They'd have been censored as an event prior to death.

The IMRT patients had higher death without progression (murdery-ness of treatment vs. co-morbid health status), and higher censoring due to lost to follow up which accounts for most (almost all) of the difference seen in PFS. At least, looking at the raw stats.
Fully correct, I was adressing the dip of the OS, not the PFS curve. The PFS would not mirror that.

Perhaps it‘s also other things that temd to be picked up in more wealthy and better cared-for patients, besides recurrences. A second primary, cardiovascular disease, whatever.
 
As-Treated IMRT (171 patients):
raw progression: 14.6% (25/171)
death without progression: 8.1% (14/171)
lost to follow up: 7.0% (12/171)

As-treated IMPT (226 patients)
raw progression: 12.8% (29/226)
death without progression: 5.7% (13/226)
lost to follow up: 2.6% (6/226)
This is all missing the exceedingly important element of temporality. The raw can be very much different than the actuarial, and can even be flipped one versus the other. (And lost to follow up when? Day 0? Day 1000? Either way they’re censors; this is normal.)
They'd have been censored as an event prior to death.
??? That needs to be better explained


I don’t have access to the actual paper. Please don’t make me get it 🙂
 
Fully correct, I was adressing the dip of the OS, not the PFS curve. The PFS would not mirror that.

Perhaps it‘s also other things that temd to be picked up in more wealthy and better cared-for patients, besides recurrences. A second primary, cardiovascular disease, whatever.
Gotcha. Agree with you as well. We were talking about 2 different things, lol.
 
This is all missing the exceedingly important element of temporality. The raw can be very much different than the actuarial, and can even be flipped one versus the other. (And lost to follow up when? Day 0? Day 1000? Either way they’re censors; this is normal.)

??? That needs to be better explained


I don’t have access to the actual paper. Please don’t make me get it 🙂
I understand all of the above and agree. I don't have access to the temporal data. But we can "assume" some elements of temporality from historic observational trials that show 95% of oropharyngeal recurrences occur within 24 months, and almost 0% occur after 48 months.

Unless this cohort was (literally) historically unique, the events between 48-60 months that form the basis of the entire difference between the PFS curves were likely deaths without progression. Could be related to murdery-ness of treatments or patient specific issues. Given patients were essentially allowed to pick their treatment after randomization, my guess would be the latter.
 
what proportion of these patients had HPV mediated disease? The 5 yr OS would suggest essentially all right? (I can't access the full pub)
About 52% never smokers, 42% had quit smoking, 8% smokers. 95% HPV positive. 76% ECOG 0.

I wish those were my average oropharyngeal cancer patients, too...
 
About 52% never smokers, 42% had quit smoking, 8% smokers. 95% HPV positive. 76% ECOG 0.

I wish those were my average oropharyngeal cancer patients, too...
Could explain feeding tube rates. I'm cool with my grizzled old population. They tank far less frequently than the young healthy guys.
 
Another question popped up, maybe a silly one, I am not familiar with how this works out in the US.

From the manuscript
Radiation target volumes were delineated by the treating radiation oncologist before randomisation.
...
Patients were treated in their assigned group except in two scenarios: patients assigned to receive IMPT were denied insurance and therefore crossed over to the IMRT group; or patients assigned to receive IMRT were approved for IMPT insurance, refused randomisation to the IMRT group, and crossed over to the IMPT group. The treating physicians had no role in crossover consideration.


How does this work out?

a) Did they ask for insurance coverage BEFORE randomizing the patients?
If so, what's the point of randomizing a patient, if you know IMPT was denied (likely the result was there in some patients prior to planned randomization)?

b) Did they ask for insurance coverage AFTER randomizing the patients?
If so, how old were the contours when they started treatment?
 
Could explain feeding tube rates. I'm cool with my grizzled old population. They tank far less frequently than the young healthy guys.

I find the "guidelines" for feeding tube placement rather vague. Do they mean 5% weight loss from baseline?

Guidelines for feeding tube placement/removal: Consideration of feeding tube insertionsshould occur at 5% weight loss, with recommended tube insertions at 10% body weightloss. The removal of a feeding tube can occur when patient does not use the feeding tubefor 3 weeks.

At the same time, in the CTCAE item "weight loss", there only appears to be a 9% absolute difference between the two groups (55.1% vs. 46.3%).
So why did a 9% difference in grade 3 weight loss (with all of those 9% grade 3 weight loss, apparently being classified grade 2 weight loss) result in an absolute increase in feeding tube rate by 14%?
1765921181512.png
 
Last edited:
Color me skeptical.

Any difference in PFS on that trial is seen after 4 years (curves literally superimposed until then). Yet, progression in OPX cancer occurs within 2 years in 90-95% of patients. OPX cancer almost "never" progresses after 4 years. Yet, there's a flurry of events between 4-5 years in the IMRT group (around the time an interval analysis may be taking place) and after that the groups track exactly together again, never widening over further follow up. Seems........odd.
Yep...
1765921554227.png


The curves for regional and distant progression are on top of each other, no differences there. According to the supplementary material all differences in terms of progression seem to be local progressions, curves separating at 4 years after treatment.

Indeed, just as you pointed out, if you look at prior trial, for example this one from MDACC on HPV+ oropharyngeal cancer, the curves drop in the first two years, particulary in the second year after treatment.
1765922084875.png
 
Last edited:
This is a really good take. There are couple of things about this trial that dont quite sit right. Some of this recaps the above thoughts
1) COI among the authors (that doesnt necessarily mean the results arent believable but its at least worth noting. And this is obviously a non blinded study. 219 were randomly assigned to IMRT. 136 (62%) were treated with IMRT.)
1a) I also dont understand why 22 are denied insurance when i thought clinical trials should be covered by insurance??
1b) the language in the publication and in some of the posts online is very strong and the results are overstated: Proton Therapy Breakthrough in Head and Neck Cancer Treatment | Michael Marash posted on the topic | LinkedIn
3) Why is it claiming superiority ("improvement in overall survival") when its a noninferiority study design? how can you have a "new standard of care treatment" when its a non-inferiority study design? Wouldnt you want to design the study to show that IMRT is non-inferior to IMPT for practical reasons (you would want to show the lower cost, widely accessible technology is the non-inferior one, right?). Why is the primary endpoint and oncologic one (PFS) opposed to QoL (is the premise that IMPT would be inferior for cancer control? this doesnt make sense to me) I feel like Im taking crazy pills and needs someone smarter than me (a statistician) to explain/justify all this.
Here are the curves for their primary endpoint:
View attachment 412815
How are the hazard ratios so different when the curves look very similar? And I must be stupid because I always thought if the hazard ratios confidence intervals cross 1 that that means the result isn’t statistically significant?
 
1a) I also dont understand why 22 are denied insurance when i thought clinical trials should be covered by insurance??
This is true to an extent. For NIH-sponsored studies, CMS will cover the treatment. This creates a bit of an ethical issue for some studies that plan to enroll patients across an age range (i.e. those under 65 would not have Medicare). Otherwise insurers are not obligated to cover experimental treatment on trial. Some private insurers allowed for coverage of proton therapy for patients on trial, or enrolled in registries, but this was likely negotiated ahead of time. If insurers were obligated to pay for treatment on study you can only imagine the abuse that would follow (and the amount of garbage studies that would be created and likely never get published).
 
Feeding tube insertion and pain are highly subjective and susceptible to bias in an unblinded study. 277 of these patients were enrolled at MD Anderson , 63% of the entire cohort. If you have a few enrolling physicians with a large volume of patients, those physicians could very easily push for more intensive pain control and symptom management in the proton patients because they have a vested interest in protons winning out. They could also delay feeding tube initiation in the cohort patients.
 
Feeding tube insertion and pain are highly subjective and susceptible to bias in an unblinded study. 277 of these patients were enrolled at MD Anderson , 63% of the entire cohort. If you have a few enrolling physicians with a large volume of patients, those physicians could very easily push for more intensive pain control and symptom management in the proton patients because they have a vested interest in protons winning out. They could also delay feeding tube initiation in the cohort patients.
Would be interesting to see feeding tube placement by location of treatment.
 
How are the hazard ratios so different when the curves look very similar? And I must be stupid because I always thought if the hazard ratios confidence intervals cross 1 that that means the result isn’t statistically significant?
It’s an upside down world I think with non inferiority trials

Ordinarily the null in a trial is “the experimental arm is not different from the standard” and HR doesn’t cross one and p value significant rejects the null

In a non inferiority the null is “the protons are worse than IMRT” here the HR crossed one and the null was rejected; the more similar the curves, the more significant the result
 
How are the hazard ratios so different when the curves look very similar?
Hazard ratios can vary significantly with similar looking curves when the outcomes are rare in both arms. Here, both progression and death are pretty rare, so this explains the HR peculiarity for this trial. It's a bad number to emphasize to the public...like emphasizing HR of chest wall recurrence for DCIS treated with XRT after mastectomy. There may be a 0.5 HR. It is probably not clinically significant.

I have no problem with the paper. But, it is not very meaningful IMO and the nature of the crossover means that the trialists were not practicing as though equipoise existed from the get-go. This is a big problem and contaminates the trial IMO. There is enough money in protons to give the treatment away to some people to make a good trial!

Should be...you get randomized and overwhelmingly you are treated per protocol, with the assumption that both interventions are equivalent.

Even intentionality can impact outcomes.

Do the following thought experiment: Imagine a prospective randomized trial with a crossover of 50% and a difference in outcomes per ITT analysis. This is not that far off regarding the IMRT arm here. The difference would mean one of two things.

1. It was rando and not reflective of intervention (typical type 1 error)
2. There is an interaction of crossover and patient characteristics or care with interventions leading to different outcomes per un-prespecified subgroups...basically a s&itstorm that makes it impossible to make inferences. Some interactions are pretty dark....like the possibility that being randomized to one arm meant you got better care in general.

If the intervention is in fact the driving factor of a difference in ITT analysis in trial with significant crossover...you expect the per-protocol impact to typically be more pronounced (again unless there is a peculiar interaction). This is not the case here.

What does bother me is the media blitz. They should not be emphasizing the likely specious survival number. The negative Torpedo trial also has to be considered (majorly considered).
 
Last edited:
Kind of sounds like you do have a problem with the paper 😛 (being tongue in cheek)
Really great points.
Tangentially related, but this is an excellent read out this week in NEJM on Intention To Treat (ITT) and Per protocol analyses of RCTs
Yeah, I have a problem with the study itself and the insane process of allowing discontinuation/crossover based on insurance approval/disapproval. By definition, this means that your randomization is bogus. Was there even really intent to treat per protocol, or rather was the intent to "treat per protocol if payment available", As discussed above, the latter is not remotely the former.

I am concerned about how contours were established prior to randomization. This itself could cause bias. These docs are proton docs and presumably are drawing contours that "work for protons". I have no reason to believe that such volumes are ideal for photon treatment. Penumbra is damn important. How many of us are comfortable with an un-contoured contralateral base of tongue volume while treating bilateral neck, because we know the dose falloff will mean 40-50Gy in that area and it lets us get OC dose down? There is no range uncertainty with photons.

For those proton docs out there? Are your contours identical with both modalities?

The paper seems to be written in fairly standard fashion. All research is difficult, and I don't do it. So, I have no problem with them publishing the paper as written. They were very unambitious. (Non-inferiority trial with 9% margin). Do they even believe in their intervention? They hypothesize about the surprising OS benefit, but who wouldn't. They should know that it is probably not real.

Thanks for the link. It's a good read. I think the concept of hypotheticals in interpreting per protocol results is really important.

In that vein, let's review what per-protocol overwhelmingly means for this trial.

The hypothetical here is that in a world where all patients can pay for protons, per protocol outcomes would reflect the real equivalence or superiority of protons vs photons. A second hypothetical may be that contours should be independent of modality?

But there is such a simple solution to avoiding these hypotheticals.

Execute the trial independent of payor status. Pay for the intervention.

Or, if as is evident by how these institutions work, the trialists don't really believe in equipoise...only offer the trial to patients who couldn't otherwise afford protons.

Enroll, pay for the intervention, customize the volumes in both arms with an understanding of the modality to be employed...how the trial should be done.
 
Hazard ratios can vary significantly with similar looking curves when the outcomes are rare in both arms. Here, both progression and death are pretty rare, so this explains the HR peculiarity for this trial. It's a bad number to emphasize to the public...like emphasizing HR of chest wall recurrence for DCIS treated with XRT after mastectomy. There may be a 0.5 HR. It is probably not clinically significant.
While I could more loquaciously quibble with some of this, in general I don't see any "HR peculiarity" here (or "pretty rare"-ness). It's all seemingly straightforward, no chicanery, etc., to my eyes.
So, I have no problem with them publishing the paper as written. They were very unambitious. (Non-inferiority trial with 9% margin). Do they even believe in their intervention?
The "9% margin" short changes just how unambitious they were.

I could honestly mathematically state they were willing to accept non-inferiority if protons were ~50% worse!

Why? They were willing to accept a proton HR of ~1.5 as declaring protons non-inferior; in other words, allowing for a ~30% vs ~20% progression/death failure rate (i.e. 71% vs 80% PFS). Now, that... a pre-planned HR that "bad" vs the standard... mine eyes have never seen I don't think.
or rather was the intent to "treat per protocol if payment available"
That seemed to be the intent.


EDIT: also just to remark on the "OS improvement" etc and measured PFS HR 0.55 (0.3-1.03) a little more: note the alpha is one sided, the hypothesized HR was ~1.5, and so the null here is "the protons are worse than the photons." No matter how good the PFS of protons were, the math/trial cannot give an honestly statistically significant OS (or PFS) improvement. The trial only yielded a signal that protons are not worse (in terms of PFS). Thou shalt not draw any further conclusions 🙂

1766087829156.png
 
Last edited:
Really enjoyed reading all of this.

Interestingly very similar studies separated by an ocean (and an ocean of different incentives of healthcare) showed different results. I wonder if bias would be taken out of studies if there were more international efforts to try to avoid bias, because our incentives are not the same. I'm sure people could point out potential biases for both of the recent studies.

Protons aren't wide spread (except in Florida), are very expensive, and the trials by people in proton centers who have made a career from it are touting about slightly decreased rates of SOB (depending on which mild grading break down you use) in breast, and now a heavily convoluted study with confounding variables everywhere that limits details claims survival benefit.

Who does this help? The head and neck patients going to these centers were probably already going to get offered protons (benefit proven or not). And the patients with head and neck cancer from everywhere else if they were sent to protons, will get delayed care. I hope nobody anywhere delays a head and neck patient for a month or months due to a study like this.
 
While I could more loquaciously quibble with some of this, in general I don't see any "HR peculiarity" here (or "pretty rare"-ness). It's all seemingly straightforward, no chicanery, etc., to my eyes.

The "9% margin" short changes just how unambitious they were.

I could honestly mathematically state they were willing to accept non-inferiority if protons were ~50% worse!

Why? They were willing to accept a proton HR of ~1.5 as declaring protons non-inferior; in other words, allowing for a ~30% vs ~20% progression/death failure rate (i.e. 71% vs 80% PFS). Now, that... a pre-planned HR that "bad" vs the standard... mine eyes have never seen I don't think.

That seemed to be the intent.


EDIT: also just to remark on the "OS improvement" etc and measured PFS HR 0.55 (0.3-1.03) a little more: note the alpha is one sided, the hypothesized HR was ~1.5, and so the null here is "the protons are worse than the photons." No matter how good the PFS of protons were, the math/trial cannot give an honestly statistically significant OS (or PFS) improvement. The trial only yielded a signal that protons are not worse (in terms of PFS). Thou shalt not draw any further conclusions 🙂

View attachment 413011
Yet another example of a large (clinically unacceptable?) delta in an NI trial. In general the delta for NI trials should be roughly 50% of the delta in contemporary superiority trials; assuming the investigators have equipoise.

And remember NI trials are generally done when the experimental intervention is cheaper, less toxic or more convenient. Three strikes and protons are OUT.

As the large pinniped marine mammal states...

"I could honestly mathematically state they were willing to accept non-inferiority if protons were ~50% worse!"

Should be an embarrassment for MD Anderson but they have no shame.
 
Top Bottom