Proton Training

[deleted525116]

Hi all. I did a forum search, but I couldn't find a recent discussion on this topic, my apologies if I missed it.

My question, for those of you more experienced than I, is how much training does it take to become proficient in proton treatment planning? If a resident at a program without protons does an away rotation for 1, 2 or 3 months, could he/she step into a job that involves protons? Does it take more, does it take less, does it take a fellowship?

I'm assuming that the radbio and physics of proton therapy can be learned anywhere, but I'm wondering about the practical training. I've come across people that have graduated from programs without protons and are now prominent figures at proton centers, are these outliers?

Again, I haven't even started training, so I apologize if this question comes across as naive, but I do appreciate any insight you all might have. Thanks!

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[mpdoc2]

Hi all. I did a forum search, but I couldn't find a recent discussion on this topic, my apologies if I missed it.

My question, for those of you more experienced than I, is how much training does it take to become proficient in proton treatment planning? If a resident at a program without protons does an away rotation for 1, 2 or 3 months, could he/she step into a job that involves protons? Does it take more, does it take less, does it take a fellowship?

I'm assuming that the radbio and physics of proton therapy can be learned anywhere, but I'm wondering about the practical training. I've come across people that have graduated from programs without protons and are now prominent figures at proton centers, are these outliers?

Again, I haven't even started training, so I apologize if this question comes across as naive, but I do appreciate any insight you all might have. Thanks!

Well you have to remember you're not responsible for designing the proton machine or even doing any of the quality assurance for it (that falls on the lap of medical physicists and engineers). You're essentially using the machine to treat patient's cancer. It's essentially the same as a regular linac except you have to be aware of the capabilities and constraints of the different beam. Something you can learn in a one month externship.

 

[deleted525116]

That's what I kind of figured/hoped. It seems like if you can plan photons and understand the science of protons you should be able to pick up proton planning pretty quickly. But again I know so little anything that I don't know what I don't know.
Several of the "top" programs don't have protons, but it seems like a short externship is simple enough if you need to learn protons for a job.

 

[Palex80]

I'd be cautious with statements like "Something you can learn in a one month externship."

It all depends a lot on what you want to do with protons.
Surely you don't have to touch the physics and target volume definition is the same as in photons / IMRT, but... proton cases can be quite challenging and you end up treating alot of cases, you rarely see in every day photon practice (chordomas, lots of children tumors), so there is a learning curve there as well. Furthermore you need to learn a lot on how often to check for plan robustness, changes in filling of bladder/bowel, etc...
One month is good to get a look into it, but I hardly think you will become "proficient" with one month of protons experience.

 

[mpdoc2]

I'd be cautious with statements like "Something you can learn in a one month externship."

It all depends a lot on what you want to do with protons.
Surely you don't have to touch the physics and target volume definition is the same as in photons / IMRT, but... proton cases can be quite challenging and you end up treating alot of cases, you rarely see in every day photon practice (chordomas, lots of children tumors), so there is a learning curve there as well. Furthermore you need to learn a lot on how often to check for plan robustness, changes in filling of bladder/bowel, etc...
One month is good to get a look into it, but I hardly think you will become "proficient" with one month of protons experience.

Most centers in the country treat chordomas and pediatric tumors with photons. I wasn't talking about proficiency to becoming a pediatric radiation oncologist or CNS radiation oncologist, I was talking about proficiency in protons.

 

[Palex80]

And I still disagree with you. You cannot achieve "proficiency" with protons with a one-month-internship.

There are a lot of pitfalls and things to watch out for. Things you cannot learn IMHO in one month.

Let me give you an example:
Chordomas are often treated with photons as you very well noted. Usually people give something like 60 Gy with photons, since dose to the OARs cannot break down that fast even with IMRT, meaning you end up getting the 80% isodose into the spinal cord / medulla oblongata / optical pathway.
Target volume delineation is not that much of a burden then, since Dmax 60 Gy normally doesn't cause other issues in the skull base.
Now, look at protons. Doses for chordomas usually range around 74-78 Gy RBE. That's a whole different ball game. You need to watch out for doses to temporal lobes, you need to check for plan robustness, need to thing about where you Bragg Peak is going to end when your patient gets a sinusitis, etc... There are quite many factors you need to take into account and believe me, you cannot learn all that stuff within one month.

But hey, surely, if you are going to use protons to give 76 Gy to the prostate, then you can learn it in one month.

 

[mpdoc2]

And I still disagree with you. You cannot achieve "proficiency" with protons with a one-month-internship.

There are a lot of pitfalls and things to watch out for. Things you cannot learn IMHO in one month.

Let me give you an example:
Chordomas are often treated with photons as you very well noted. Usually people give something like 60 Gy with photons, since dose to the OARs cannot break down that fast even with IMRT, meaning you end up getting the 80% isodose into the spinal cord / medulla oblongata / optical pathway.
Target volume delineation is not that much of a burden then, since Dmax 60 Gy normally doesn't cause other issues in the skull base.
Now, look at protons. Doses for chordomas usually range around 74-78 Gy RBE. That's a whole different ball game. You need to watch out for doses to temporal lobes, you need to check for plan robustness, need to thing about where you Bragg Peak is going to end when your patient gets a sinusitis, etc... There are quite many factors you need to take into account and believe me, you cannot learn all that stuff within one month.

But hey, surely, if you are going to use protons to give 76 Gy to the prostate, then you can learn it in one month.

I've never heard of someone treating chordoms to 60 Gy with IMRT. We treat them to atleast 70 Gy using photons.

 

[Palex80]

Go ahead, give 70+ Gy with photons to this:

Guess what... You 70 Gy isodose is in the brainstem... Ooops!

 

[Neuronix]

The PTV is in the brainstem...

 

[mpdoc2]

Go ahead, give 70+ Gy with photons to this:

Guess what... You 70 Gy isodose is in the brainstem... Ooops!

Pretty sure Protons will mess the guy up pretty badly too.

 

[Palex80]

Precisely the PTV is in the brainstem.

However treating this patient with protons will result in a Bragg peak at the posterior part of the tumor with a very steep dose drop to the brainstem. So if you are willing to accept a underdosing within 2mm of the posterior part of the tumor, you can treat the patient to a high dose with protons. You cannot do that with photons however, cause you cant get the dose to drop from 74 Gy to 60 Gy within 2 mm. On the other hand there is quite solid date on RBE for protons being higher within the Bragg Peak area, meaning that if you dont plan this right, you are going to fry the brainstem.

Anyways my point is (and this is coming from someone who spent 6 months in a proton facility in a fellowship): You cannot learn these things fast.

 

[mpdoc2]

Precisely the PTV is in the brainstem.

However treating this patient with protons will result in a Bragg peak at the posterior part of the tumor with a very steep dose drop to the brainstem. So if you are willing to accept a underdosing within 2mm of the posterior part of the tumor, you can treat the patient to a high dose with protons. You cannot do that with photons however, cause you cant get the dose to drop from 74 Gy to 60 Gy within 2 mm. On the other hand there is quite solid date on RBE for protons being higher within the Bragg Peak area, meaning that if you dont plan this right, you are going to fry the brainstem.

Anyways my point is (and this is coming from someone who spent 6 months in a proton facility in a fellowship): You cannot learn these things fast.

You didn't need a 6 month fellowship to know that.

 

[Palex80]

That's your opinion. I am not familiar with what you need in the US to be able to treat with protons on your own. In several European countries (for example Germany) you need to pass an extra exam, demonstrating that you are comfortable with this technique and need to have had a 6 month training in a proton-only facility + 100 documented cases treated.

 

[mpdoc2]

That's your opinion. I am not familiar with what you need in the US to be able to treat with protons on your own. In several European countries (for example Germany) you need to pass an extra exam, demonstrating that you are comfortable with this technique and need to have had a 6 month training in a proton-only facility + 100 documented cases treated.

In the United States, you don't need to take an extra exam to treat with protons. All learn about protons during their radiation physics course which they're examined on after their 3rd year.

 

[Cancerdancer]

In the United States, you don't need to take an extra exam to treat with protons. All learn about protons during their radiation physics course which they're examined on after their 3rd year.

You might not need an extra exam, but don't give our European friends the impression that a simple shoddy introduction to the physics of protons is deemed sufficient in the U.S. for our docs to feel comfortable with protons. There are many clinical issues unique to protons, including generally poorer image guidance capability, plan robustness, and beam-path issues that are not covered/taught/tested in a general residency. An astute practitioner would want training closer to what Palex is describing than something much shorter. Sure, we can all contour and cover a prostate, but being thoughtful in the base of skull when using 74+ Gy or in complex peds cases requires exposure to cases that you might not see enough of in a 1 month externship.

 

[mpdoc2]

You might not need an extra exam, but don't give our European friends the impression that a simple shoddy introduction to the physics of protons is deemed sufficient in the U.S. for our docs to feel comfortable with protons. There are many clinical issues unique to protons, including generally poorer image guidance capability, plan robustness, and beam-path issues that are not covered/taught/tested in a general residency. An astute practitioner would want training closer to what Palex is describing than something much shorter. Sure, we can all contour and cover a prostate, but being thoughtful in the base of skull when using 74+ Gy or in complex peds cases requires exposure to cases that you might not see enough of in a 1 month externship.

That of course is the case no matter what modality you're using to treat.

 

[Reaganite]

I trained on protons. The idea you can learn everything you need to learn in one month is well, dumb. Palex and Cancerdancer are being nice. Chordoma plans are a beast, and you sure as hell won't get enough exposure to CNS planning in a one month externship to make you proficient in treating them. You're dealing with matches, patches, distal edge RBE effects, etc. etc. Even the other proton docs are reluctant to get involved in the planning if the dedicated CNS guy is on vacation.

 

[mpdoc2]

I trained on protons. The idea you can learn everything you need to learn in one month is well, dumb. Palex and Cancerdancer are being nice. Chordoma plans are a beast, and you sure as hell won't get enough exposure to CNS planning in a one month externship to make you proficient in treating them. You're dealing with matches, patches, distal edge RBE effects, etc. etc. Even the other proton docs are reluctant to get involved in the planning if the dedicated CNS guy is on vacation.

Maybe you're a slow learner.

 

[Cancerdancer]

Congrats on having the last word there...you win I guess

 

[thecarbonionangle]

how much should having exposure to protons during residency play in our ranking of programs? how important is it come job search to say "i trained with protons"?

 

[medgator]

how much should having exposure to protons during residency play in our ranking of programs? how important is it come job search to say "i trained with protons"?

Depends on who you ask, or what you believe will happen to proton reimbursement going forward. I personally don't think it's a big deal. The data is lacking for probably the biggest indication in terms of patient numbers, namely prostate


http://www.ncbi.nlm.nih.gov/pubmed/22511689

http://forums.studentdoctor.net/threads/iu-proton-center-closes-down.1100101/

http://www.advisory.com/daily-brief...beam-therapy-comes-under-attack-from-insurers

 

[RadRadRad]

Don't see how passing the radiation physics exam after the 3rd year (which asked very little about protons) documents a proficiency in treating with protons. (I would venture to say you could get every question about protons wrong and still pass the exam).
Highly doubt a 1 month fellowship would make you proficient in using protons.

 

[Linaculous]

how much should having exposure to protons during residency play in our ranking of programs? how important is it come job search to say "i trained with protons"?

Depends on who you ask, or what you believe will happen to proton reimbursement going forward. I personally don't think it's a big deal. The data is lacking for probably the biggest indication in terms of patient numbers, namely prostate


http://www.ncbi.nlm.nih.gov/pubmed/22511689

http://forums.studentdoctor.net/threads/iu-proton-center-closes-down.1100101/

http://www.advisory.com/daily-brief...beam-therapy-comes-under-attack-from-insurers

I tend to agree. Protons have a somewhat uncertain future, and there are too many great programs without protons to pass up on. I think there are more important things in a program to consider.
Of course, as a PGY1 I don't have the experience to answer with any authority, but that was the unanimous advice I got last year from my home program, which is affiliated with a proton center (for what it's worth).

 

[Palex80]

My highest hopes in particle therapy is not about the reimbursement getting better.
Let's face it: The med oncs get their drugs reimbursed even if they cost hundreds of thousands of dollars (prominent example is ipilimumab here) because they have managed to document a survival advantage in diseases, who were deemed hopeless with past treatment and even some long-term survivors. We cannot expect the same for protons. Not for every-day diseases like melanoma. Surely, you can cure more chordoma patients with particle therapy and such therapy should be adequately reimbursed. However you cannot expect to make money (or even sustain a proton facility) by treating chordomas alone.

My highest hopes lie in modern technology overcoming the problems in current particle therapy facilities. I hope lasers or dielectric wall accelerators will deliver reliable, cheap, robust and small particle therapy treatment units. Then reimbursement should become less of an issue as it is now. You still have to watch out for all the pitfalls in treating patients with protons, but at least you wont have the huge costs associated with today's facilities.

 

[couchkick]

I don't know about using the Sheets paper. My understanding is that many proton centers are not SEER reporting and were not included in this. Only very few centers were actually included. Furthermore the majority of the proton data out there is not IMPT. The question will be if IMPT can give a a clinical benefit over IMRT.

 

[medgator]

I don't know about using the Sheets paper. My understanding is that many proton centers are not SEER reporting and were not included in this. Only very few centers were actually included. Furthermore the majority of the proton data out there is not IMPT. The question will be if IMPT can give a a clinical benefit over IMRT.

Even if it can, what kind of QALY/cost benefit are we looking at here.

 

[Scatter]

Anything short of a 6-12 month fellowship is tantamount to winging it.