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Yes.
ASCO 2026
Started by Palex80
Long-term outcomes of 18F-fluoromisonidazole positron emission tomography (FMISO PET)–guided major radiation dose de-escalation in HPV-associated oropharyngeal cancer: The 30 ROC approach.
5-year results: selected patients (>300), treated with 30Gy, 5year local failure rate of 2.2% (vs 1.9% in the hypoxic 70Gy group)
Still very impressive results..
Surprising. What studies are you referring to?
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Those oropharynx proton appeal letters for medical necessity just became about twice as awkward to write
Money to made in imaging to reduce xrt demand 🤷
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Yes and no. The trials are already being developed. I agree with you that the modality in the most trouble is probably surgery. So whether this ends up being a net gain or loss for rad onc will vary greatly by region.
There are multiple questions being asked but they all start with EVP and go something like this:
Neoadjuvant with response-based treatment decision
Give EVP for a few months and if they have T1 or T0 disease post EVP continue to bladder preservation with RT+IO (or CRT); if they have worse disease operate
Give EVP for a few months and if they have a cCR, continue pembro for a year and observe -> RT or surgery if they have residual disease
Or what is coming...
Just give a longer course of EVP with no further therapy until failure
Randomized trials comparing EVP alone to CRT coming online looking at OS.
My take, EVP alone probably will have equivalent or better survival than standard CRT. The systemic disease control will probably be better and many of the patients who do have local recurrences will probably be salvaged with CRT or surgery. But that gets to the bigger question beyond survival. How many of the patients treated with EVP alone will eventually need salvage therapy and how well do they do? Lets extrapolate from the peroperative trials with a 56% pCR. They do get a little more drug after surgery so lets assume the pCR is 65% (I doubt its that high) and the local failure rate ends up being 35%. If the primary goal of treatment is organ preservation (which is how the trials sell them) the question becomes which approach gives you a better organ preservation rate: giving EVP and only radiating the people who have a failure or doing neoadjuvant EVP + RT upfront. Either way, if the patient and oncologists mindset going into treatment is organ preservation, it is likely that many US centers which are dominated by surgery could end up seeing more bladder patients. I've been at both extremes. Where I was previously, i treated a lot of bladder patients and their volume is definitely going down. Where I am now likely stands to benefit greatly from these studies. Just depends on local practice patterns.
Imaging isotopes and dietary protein, so hot right now.
I can’t think of another solid tumor site with highly active chemotherapy where we just give systemic therapy alone and wait for local failure. Is the difference for bladder that the local treatments are so toxic?
In my experience carefully-designed definitive chemoRT for bladder cancer is not tremendously toxic.
Especially if it is bladder only. I used to do 2-3 cases per month. Almost all 55/20. Most had few side effects. I suspect some people under report because the severity of dysuria with radiation pales in comparison to the immediate post TURBT period (which many had experienced more than once).
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No one does sequential anymore I guess. They seem to do fine with 45/25 IMO with imrt followed by a partial bladder boost
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Dynamically adapted natch
Don’t forget peptides!
If as a patient you have the realistic option to only get 30Gy to your head and neck instead of 70Gy it is money well spent.
This is much more usefull than all the 5fx vs 3fx vs 2fx studies going on
To my knowledge the 30Gy group also recieved less chemotherapy btw
And there are also studies looking into dose escalation for hypoxic tumors.....
Every poster looks AI generated now
At the very least this work validates de-escalation doses to elective neck
I also agree that in 20 years we will be doing very few cystectomies. I also forsee relatively little bladder XRT.
The difference is that most local bladder failures after EV-pembro are superficial and easily salvagable with a minor procedure (TURBT) +/- minimally toxic intravesical therapy. We are also in a new era of intravesical therapy with a ton of options, of which i forsee inlexzo (gemcitabine sustained release from an indwelling silicon delivery system) being the pre-eminent option.
My belief is that there will still be a small niche for definitive local therapy, but it will be quite narrow.
EV-Pembro->complete response and negative ctTNA -> observe
EV-pembro-> persistent ctDNA -> disease is mostly systemic and unclear if any local therapy will have a benefit. my guess it will mostly be palliative
EV-pembro-> persistent local disease with negative ctDNA: when possible this will be managed by TURBT and likely inlexzo. if bulkier or multifocal or persistent T2 then that is the role for cystectomy or chemoXRT.
There are still a few hurdles here. We are not very good at identifying complete responses short of taking out the bladder. This will improve with imaging/blood/urine markers.
FWIW bladder XRT is pretty rough and far worse then prostate. My patients who have responded oncologically well to bladder XRT often have severe LUTS and/or ureteral strictures, though the bar is low when comparing to cystectomy outcomes.
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This is spot on and should really concern rotating medstudents . Bladder cancer is a typical heterogenous soldi malignancy. It is not driven by a virus or driver mutation. Residents should be very worried that this is the first dominoe.
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Chemo IO is talked about in nsclc but I don't see it happening
it would w/ 50+ % path cr.
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Huh? They were just trying to show adding Durvalumab wasn’t harmful?
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"Durvalumab won't make you die faster in the setting of noninvasive malignancy. It's inclusion represents a new standard of care."
I think you're right about the future of this disease.
I wonder though, if bladder XRT would seem as rough if selection was better. I know you aren't doing this, but the majority of the time I get sent an unhealthy 70-80-90 year old person that no one would dare operate on and the plan is for RT with cisplatin. That would be tough on me as a decently healthy 47 year old! Once in a blue moon, I get a healthy person that has "done their own research" and chooses CRT. They often do very well. MUCH worse than prostate for obvious reasons, but not like the very old unhealthy types that are the usual bladder preservation referrals.
The somewhat unique “twist” with bladder RT is that the “rubber hits the road”/cellular CTV is less than half a percent, maybe less than a tenth of a percent, of the necessary PTV. Doing poor man’s DART for bladder really made a clinical difference for me in my practice. I always treat whole bladder whole way through in an Erlangen/UMich style. I never made peace with the MGH approaches, especially after seeing a few cystoscopies with my own eyes.
Agreed. What's your preferred dose? I've seen 35/10 before when the volumes get pretty big
For no residual disease: 6 x 5 Gy and (seldom) 10 x 3.5 Gy for big cavities. We boost residual disease.
We use HyperArc. We add a 3mm lesion to the cavity.
Cavity plus 3mm is your CTV or PTV
If by boost you’re alluding to inhomogeneity, ideally it’s not hurting anything, and it can serve to draw the 50% isodose inwardly closer to the cavity surface
Both, kind of. It‘s 2mm CTV + 1mm PTV. And we contour a "generous" GTV for the cavity.
95%. We do not increase the dose centrally. Not for cavities. If there's suspicion of residual disease, we SIB that to 6 x 6 Gy.
Which is exactly what I do not want to have, lol.
I like to see that 6 x 4 Gy isodose a bit further away beyond my PTV edge.
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But.... why? If you're worried about disease further from the cavity wouldn't it be better to just, you know, extend the CTV and/or PTV?
I used to enjoy these discussions but eventually realized they lead nowhere. Being an ICRU 50 purist is maybe laudable for consistency’s sake. On the other hand, the way these terms are defined, he *is* extending the PTV. It just becomes more difficult in his case to be precise about the amount of this expansion versus someone doing it in a systematic fashion. Almost no way to know who’s right and who’s wrong regarding precise versus inchoate expansions especially in the absence of a GTV. I was at a Herman Suit proton lecture once and he said “there is not any clinical indication for even one picogray of dose outside the tumor volume.” And I thought yeah that’s a nice sentiment but it assumes perfect tumor volume knowledge.
Nobody’s perfect.
Yes, I could. But I think 3mm is fine already.
We generally underestimate how much incidental dose we deliver to volumes that may be at risk, but are not "true" CTVs. Think of SBRT for centrally located lung cancer and how some like to "draw" the isodoses closer to the hilus region.
This is a “I am an artiste with my dosimetric paintbrush” approach versus being a J. Evans Pritchard, PhD, with the doses… I ripped his intro from my textbook too. Although I eschew making firm declarations just by throwing some doublespeak like “‘true’ CTVs” into the convo. First tell me what a false CTV is!
EDIT: I was just thinking this is akin to opposed lateral 3D versus IMRT for early glottic. The 3D people are like “my opposed laterals better treat the adjacent lymph nodes that *might* be involved versus multi field IMRT or VMAT.” And then you ask: well why don’t you just contour the nodes for early glottic? “Well now I don’t wanna go THAT far.” It’s like a Bob Ross happy dosimetric accident, my opposed laterals for glottic…
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High tangents entering the chat, as well as electron beam lmao
I see enough malpractice cases brought for a colostomy after SBRT for intact prostate. No interested whatsoever in doing it for post-op.
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MonolithBeam
New Member
I feel like we did that already and it didn’t work
One awesome way to solve all these problems is never do SpaceOAR.
(Edit: seems I placed this in the wrong thread, but consider my pithy comment like a foreign object that doesn’t belong here.)
(Edit: seems I placed this in the wrong thread, but consider my pithy comment like a foreign object that doesn’t belong here.)
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