The frustrating part of this is that this is probably an ideal situation for protons.
With imrt or pa obliques there is little significant anterior dose. I have palliated so many pts over past 7 years on io without issue.
Little but not none. All things being equal, would you treat vertebral mets with protons if you could?
This and the wolf of wall st between MM and DiCaprio are simply timeless
Sure and I'd get a Lambo urus as my family weekend car if i could too
Boiler Room, Wolf... and Baldwin Glengarry
I would. Cost and availability aside, protons (done well) are likely better in many clinical situations… especially in patients with slow-moving oligoprogressive cancer where multiple courses within an organ are anticipated. The question is: will the cost of delivery decrease enough to make it a reasonable choice in these situations?
That's what I mean when I say it's frustrating. We know what the best thing to do is, but in most cases we can't. Its glaring when I talk about doing protons in bone palliation, but we are confronted with this daily.
I'm talking about a PA beam that ends at the anterior portion of the vertebral body. Hence, no exit dose into the bowel, No GI side effects, no nausea.
Fair enough.
Can’t we all already ensure no GI side effects or nausea with super anal retentive IMRT planning for spinal mets (like Obi Wan would say, it’s my speciality)
Consider this. Stomachs and bowel routinely got (and still do) 30 Gy in 10 Fx with APPA spine plans. No one batted an eyelash and patients did fine.
Agree (and some acute toxicity in some patients admittedly)
Not advocating protons. Simply saying if you got two plans that cost the patient the same, and 1 plan had literally 0 bowel dose, you probably wouldn't think too hard about which to approve.
I stopped using apppa 10+ years ago. Never experienced bowel toxicity during palliation. ever.
Except I would. IMO there are two basic ways to grade a plan. First, it's dosimetric value on the computer (coverage, conformality, hot spots and OAR coverage). Second, the robustness of the plan (or how the plan looks when it's not quite delivered with zero uncertainty in position or tissue density or other sources of uncertainty).
Pts in a lot of pain can’t wait a week for protons.
Two different things. I have no doubt plans look better. Meaningful therapeutic benefit?
Plans look better for prostate as well, but toxicity is likely worse. Would you get protons for prostate? How about without a spacer or balloon?
Prostate alone - spacer and IMPT (small improvement here mostly related to testicular dose/testosterone function longterm)
Two people each hand you a plan for SBRT to a large adrenal met… one has Left kidney V15 = 60%, the other V15 = 20%. How do you KNOW that dosimetric difference is going to result in a meaningful therapeutic benefit? Personally, I do afford SOME faith in the value of a DVH.
Claiming that IMPT offers improved outcomes with regards to testosterone function is a bit of a stretch, yes?
Here is the proton data which was also discussed in the article. Proton Testosterone function I think it is well documented that testicular radiation has the ability to lower testosterone function, either temporarily or permanently. 40% of the patients in the previously linked article had permanent decrease after photon treatment. This is not a risk in proton treatment where testicular doses are near-zero.
I got no protons. Would be a fan of seeing no exit dose on a pa spine plan. Wouldn't use protons for prostate.
I stand corrected !!
Sometimes it's all Cigna/humana etc will pay for, and sometimes the pt isn't well enough to lay down for a 3-4 field "complex" plan since they won't pay for 3DCRT or VMAT
Again, is this clinically meaningful though? It's one thing if you're going from "some level of testosterone" to "no level of testosterone", but does a "median percentage of decrease to the nadir [of] 30%" have any sort value beyond a number on a lab test? What if I contour the testicles every time and ask my planners to keep dose (other than scatter) completely out of the testicles to the best of their ability? Couldn't I dump dose into the soft tissue of the thighs and achieve the same effect?
I think my patients appreciate sparing their testicular function. It is a good reason to use protons in pelvic RT for men who care about their sexual function. You can definitely shape your IMRT plans differently but then the femoral heads take a beating.
Protons are a very small amount of radiation oncology spending. IMRT takes up a huge portion of radiation oncology spending and there is very little randomized data to support the use of IMRT with IGRT over 3DCRT with weekly port films, and its more expensive and recommended for nearly every disease site.
Proton spending is high! Very few pts have pure Medicare. Jordan’s data show that protons are 17-55% overall commercial xrt spending. Negotiated proton prices are often 5-10 x cms prices for imrt! To list just the Medicare component is highly misleading. (Medicare pays 80%of cms price, but then the supplement kicks in and pays 400%-1000% or the employer pays some exploitative 500-1000% of cms. I may be underestimating here, because the likely worst offenders mdacc and mskcc have not released their prices.
Exactly. Patients with bone met pain have a tendency to wiggle and squirm on the table. Especially germane/noticeable if you ever take a "hang with the therapists day" and watch the in-room video feed all day long.
The "IMRT has little randomized data too" argument is a rabbit hole, but I'll note that this pie chart is using 4-7 year old data when there were probably 22-27 proton centers in this country, and I think there are at least 37-38 currently, a 60-70% increase. I don't think this is accurate in 2021 and beyond. I'm sure @TheWallnerus has 3 bar graphs teed up on this (which may have already been posted and I forgot).
The graph is misleading. Not to a huge degree perhaps but it ain't the whole picture.
The main reason Canada health service sends patients to the US for RT is for protons. On average, US centers charge Canada $350K per patient for this cross-border beneficence.
I concede that my opinion of protons is based on 3 things. Conversations with people I know well (who I trust will be honest with me) who work with them, my sense of a tremendous paucity of data despite years of use at prestigious academic centers, and a rudimentary understanding of dosimetry.
I don't lose sleep over someone choosing IMRT for P+SV, but I did want to point out a toxicity difference of IMRT vs IMPT that is not often discussed.
I guess I should talk to Canada. We would accept 1/10th of that amount with a smile. Anyone got their number?
You still using 3D to treat your locally advanced lung and head and neck cases?
I'm not a clinical trialist but I can tell you that we enroll on a number of clinical trials comparing protons to IMRT. So they are ongoing, but they are very difficult to make and even more difficult to enroll/randomize patients. Patients on clinical trials will get randomized to protons and then their insurance will refuse to pay for the treatment - this happens all the time.
What about charging IMRT rates until there is proof of superiority?
To be honest, not our problem 🤷♂️. It's not up to the general radiation oncology community to prove that protons may or may not be helpful. Like asked above, would you treat most sites definitively with 3D? All of the proton people always distract with that argument, shying away from the fact that all protons have published are arguably weak studies.
Proton users "picking on" IMRT is worse than Ed Halperin's old saw that there is no randomized data to support the use of linacs over cobalt.
