Breast WBI Fractionation discussion

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I believe in START-A, the *****13 fraction to 39 Gy****** arm had improved cosmesis.

Monkey needs to be using 13 fractions instead of 15 as I previously hinted :)

h0VOK0U.png

At least you brought data, not sure why you are misrepresenting it as just in favor of 39/13 when there are clearly cosmetic benefits in both plots, including the 40/15.

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START showed improved cosmesis? Citation for that statement? I was not aware of HypoFx showing improved cosmesis in anything besides retrospective studies or in well selected patients (like larger breasted women, like in that MDACC trial I think?)

Not sure what scenario you would think that 2.67 x 15 is closer in BED to 2 x 25 than 2.66 x 16, but here's the evidence that you are incorrect.

50/2: View attachment 323484

42.56/16:View attachment 323485

40.05/15: View attachment 323486



I agree with Mandelin Rain that trying to make 16 vs 15 an issue is more representative of you as a person than it is of me as a person. There is zero monetary advantage of me doing 16 vs 15, unless it's a left breast and I get to charge for one extra daily kV. If Evicore told me I was only authorized for 15, I'd be like 'whatev' and move on with my life. I boost most of my ladies, and I still get them done in 20 treatments. Maybe you can get yours done in 19 if you did 15 + 4fx boost?

This isn't about the money or fractions. I did make a comment about losing a fraction above which was disingenuous and not the gist of the argument, probably was uncalled for and I recant. I actually just believe the cosmesis is slightly better and as scarb pointed out, the forest plot confirms (for BOTH fractionations).

Also, maybe here is why they don't use 39Gy scarb... inferior local control (not SS to be fair), although 41.6 might be fair game.

1605813594744.png
 
OK, thanks for sharing. I agree 13 or 15 fx does seem to show better toxicity, ~50% of these patients received boost, although it was about equal across arms. We know 50/25 + boost is more toxic than 50/25, while Whelan didn't allow for boost on their trial. Not sure what that means. Maybe 40/15 and 42.56/16 are analogous to what we saw in FAST and FAST-Forward?

Interesting - not sure if this is something that I had paid attention to. Then perhaps it is time to change practice down to 15 tx, with the caveat that cross trial comparisons on toxicity are tough.

@radmonckey if you boost are you doing it in 4 or 5fx?
 
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OK, thanks for sharing. I agree 13 or 15 fx does seem to show better toxicity, ~50% of these patients received boost, although it was about equal across arms. We know 50/25 + boost is more toxic than 50/25, while Whelan didn't allow for boost on their trial. Not sure what that means. Maybe 40/15 and 42.56/16 are analogous to what we saw in FAST and FAST-Forward?

Interesting - not sure if this is something that I had paid attention to. Then perhaps it is time to change practice down to 15 tx, with the caveat that cross trial comparisons on toxicity are tough.

@radmonckey if you boost are you doing it in 4 or 5fx?

Boost in 5, need that extra fraction ;) . Seriously though I do use 1000/5, although logically weird to switch up fractionation.

Also, you got me on the BED stuff earlier for the most part, although what I said actually does hold true and for an a/b of 0.68, 50/25 = 40/15 to be fair. Probably an unrealistic a/b! Although perhaps 50/25 is too much to begin per START results.
 
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At least you brought data, not sure why you are misrepresenting it as just in favor of 39/13 when there are clearly cosmetic benefits in both plots, including the 40/15.
To me it looks like 39 wins over 40 though??? 15 wins over 16? Trump won 2016 in a landslide? ;)
 
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To me it looks like 39 wins over 40 though??? 15 wins over 16? Trump won 2016 in a landslide? ;)

Well, depends if you prefer less breast shrinkage (40), or less breast induration (39)? Might start asking women which one they like, kind of like a menu with check boxes :p. Pretty sure the 95% CI's overlap between all the 39 and 40 metrics. Also, I know you've been tempted, but thanks for not going down the hypofx boost rabbit hole yet ;) .
 
Well, depends if you prefer less breast shrinkage (40), or less breast induration (39)? Might start asking women which one they like, kind of like a menu with check boxes :p. Pretty sure the 95% CI's overlap between all the 39 and 40 metrics. Also, I know you've been tempted, but thanks for not going down the hypofx boost rabbit hole yet ;) .
Ha no rabbit holes. But the 39/13 vs 40/15 argument re: side effects seems dumb. The avg HR is 0.64 for 39/13 and 0.66 for 40/15. It's all navel gazing. 13 vs 15 vs 16 vs 45/25 plus boost (which I'm sure Jay Harris is was still doing time to time). It's all fine. It all works. It's all good medicine. The first real study here was Whelan's, and in the conclusions section it was all about: 16 is more convenient than 25. It was, ostensibly, all about convenience.

The doc that offers the most convenient, acceptable regimen to their patients "wins." As opposed to a gray e.g., convenience is subjective. However, maybe it's not. The fewest treatments equals the most convenient? If so, I will win with IORT.
 
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Ha no rabbit holes. But the 39/13 vs 40/15 argument re: side effects seems dumb. The avg HR is 0.64 for 39/13 and 0.66 for 40/15. It's all navel gazing. 13 vs 15 vs 16 vs 45/25 plus boost (which I'm sure Jay Harris is was still doing time to time). It's all fine. It all works. It's all good medicine. The first real study here was Whelan's, and in the conclusions section it was all about: 16 is more convenient than 25. It was, ostensibly, all about convenience.

The doc that offers the most convenient, acceptable regimen to their patients "wins." As opposed to a gray e.g., convenience is subjective. However, maybe it's not. The fewest treatments equals the most convenient? If so, I will win with IORT.

The 39 vs 40 comment I made was a joke btw, which I alluded to with the menu and overlapping CI comment, but whatever guess it was dumb. You are the one who brought up 39 and kept pushing it for the record. Agree that everyone in this thread is practicing good standard of care medicine from what I can gather. Was pretty sure my entire residency and career to date had been based on splitting hairs. Probably an indictment of the field but I didn't create that. I guess I picked the wrong hair to split based on the reaction.

I am honestly somewhat blown away by the vitriol generated by the simple comment of "do you think that perhaps going from 4005/15 to 4256/16 represents a meaningful jump on the NTCP curve based on the observed data in these large level 1 trials?".

Maybe I should just mention breadlines to keep the likes flowing.
 
Lolz, whoa guys. I promise I will no longer subscribe to fringe and blasphemous theories like "more dose equals more side effects" lest my character be questioned again.
Oh. The 15 vs 16 argument is one on side effects. I thought you were trying to say it’s more convenient or cheaper. But of course you’re right. 40/15 would have less side effects than 42.5/16. But If it’s just a side effects argument over dose, then you have to let boost back in the convo. One should never ever never ever do 15+5. 16 would always be better than 15+5. I have probably treated a thousand patients with 16. Not a single one ever got boost. In theory they could have less side effects than a cohort of patients getting a mix of 15 and 15+5. And also, again in theory, the practice, and added dose, of boost in hypofractionated WBI is the most common widespread practice amongst rad oncs for which there is zero randomized data to support the added “risk” of side effects.The risk/benefit ratio of boost in hypofx WBI is unknown. Earlier you said “I actually don't understand how anyone could give 16 over 15.” Can I say I don’t understand how anyone could give 15+5 over 16?
 
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Oh. The 15 vs 16 argument is one on side effects. I thought you were trying to say it’s more convenient or cheaper. But of course you’re right. 40/15 would have less side effects than 42.5/16. But If it’s just a side effects argument over dose, then you have to let boost back in the convo. One should never ever never ever do 15+5. 16 would always be better than 15+5. I have probably treated a thousand patients with 16. Not a single one ever got boost. In theory they could have less side effects than a cohort of patients getting a mix of 15 and 15+5. And also, again in theory, the practice, and added dose, of boost in hypofractionated WBI is the most common widespread practice amongst rad oncs for which there is zero randomized data to support the added “risk” of side effects.The risk/benefit ratio of boost in hypofx WBI is unknown. Earlier you said “I actually don't understand how anyone could give 16 over 15.” Can I say I don’t understand how anyone could give 15+5 over 16?
My feeling is 16 fx is a little boost in women for whom boost is not necessarily indicated, like a very healthy 70 yo. Otoh, if a boost is recommended,TN, young etc, I opt to lower dose to the whole breast and give more to the area most concerning for recurrence, which also makes my heart and lung dvh look 1/16 or so better.
 
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More dose = more side effects
More dose = better tumor control

Maybe YOU just don't care about curing cancer.
 
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Oh. The 15 vs 16 argument is one on side effects. I thought you were trying to say it’s more convenient or cheaper. But of course you’re right. 40/15 would have less side effects than 42.5/16. But If it’s just a side effects argument over dose, then you have to let boost back in the convo. One should never ever never ever do 15+5. 16 would always be better than 15+5. I have probably treated a thousand patients with 16. Not a single one ever got boost. In theory they could have less side effects than a cohort of patients getting a mix of 15 and 15+5. And also, again in theory, the practice, and added dose, of boost in hypofractionated WBI is the most common widespread practice amongst rad oncs for which there is zero randomized data to support the added “risk” of side effects.The risk/benefit ratio of boost in hypofx WBI is unknown. Earlier you said “I actually don't understand how anyone could give 16 over 15.” Can I say I don’t understand how anyone could give 15+5 over 16?

This is logically sound and I respect your take. I was a bit curious about your actual practice patterns given prior conversations and it appears you put your money where your mouth is. If you are not boosting, Whelan in 16 is the purest data in the land.
 
Appreciate the thoughtful discourse everyone. The thread got a little derailed at first and to be honest I contributed to that. Here is a quick summary on where I'm at on this matter, and briefly why it might be worth considering further. This is our bread and butter, probably highest % caseload of many practices. When you see a woman with a painful or disfigured breast, they are not happy. Any room for improvement should be considered, given the scale of treatment nationally and internationally.

Why 15 MIGHT be better than 16...

WHELAN: 612 women, 4256/16 vs 50/25, no boost, 10 year follow up

Local control: dead even

1605929627547.png


Cosmesis: dead even

1605929715295.png


Great study, practice changing, widely adopted with time.


START B: 2215 women, STRAIGHT 1:1 randomization (no 2:2 or whatever everyone else is claiming, yes they lumped 2 studies in the 10 year pub but START B was its own thing) 50/25 vs 40/15, **boost allowed at treating MD discretion, even boost #s between arms, confounder.

Local control: Statistically dead even (crudely favored 40/15, not SS)

1605929969163.png


Cosmesis: SS favored hypofractionation significantly

1605930018225.png


Many more patients that Whelan, at least equal tumor control, impressive improvement in cosmesis, boost allowed. New standard? Improvement on Whelan?


FAST FORWARD: 4096 women, 1:1:1 rando to 40/15, 27/5, or 26/5. 5 year follow up.

Local control: dead even

1605930476740.png


Cosmesis: Clearly worse for 27/5, somewhat comparable for 26/5 vs 40/15, but some factors superior for 40/15

1605930578447.png


As @scarbrtj has said, the therapeutic window for radiotherapy can be annoyingly small. Seriously, 1Gy makes the difference?? Also, to @evilbooyaa credit, the brits were way too willing to gloss over some of the differences between 40/15 and 26/5 in issues such as breast induration, telangiectasia, and breast/chest wall (o)edema to further their agenda of decreased utilization.


SUMMARY

Whelan: was a practice changing study and remains a go to standard in US and Canada. Same outcome, less treatments.

START B: essentially one less fraction than Whelan, replicated Whelan otherwise and proved no detriment in tumor control with improved cosmesis. Allowed boost which is a bit of a confounder. We know boost is detrimental to cosmesis.

FAST FORWARD: 40/15 still looked like the winner to me. And shocking difference between 27/5 and 26/5. If one gray can make all the difference is this large phase 3 study, couldn't an additional 2.6 Gy fraction of whole breast radiation be the difference maker in cosmesis between 40/15 and 42.56/16?

FINAL TAKEAWAYS:

- I like to ponder pathetic questions like whole breast in 15 vs 16
- There might be a small toxicity difference between the two and given the scale of the diagnosis and treatment, its worth considering further even if it seems too basic
- If you are looking for the cleanest data without a boost, its Whelan
- If you want to boost, consider 40/15 as the whole breast portion
 
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Appreciate the thoughtful discourse everyone. The thread got a little derailed at first and to be honest I contributed to that. Here is a quick summary on where I'm at on this matter, and briefly why it might be worth considering further. This is our bread and butter, probably highest % caseload of many practices. When you see a woman with a painful or disfigured breast, they are not happy. Any room for improvement should be considered, given the scale of treatment nationally and internationally.

Why 15 MIGHT be better than 16...

WHELAN: 612 women, 4256/16 vs 50/25, no boost, 10 year follow up

Local control: dead even

View attachment 323596

Cosmesis: dead even

View attachment 323597

Great study, practice changing, widely adopted with time.


START B: 2215 women, STRAIGHT 1:1 randomization (no 2:2 or whatever everyone else is claiming, yes they lumped 2 studies in the 10 year pub but START B was its own thing) 50/25 vs 40/15, **boost allowed at treating MD discretion, even boost #s between arms, confounder.

Local control: Statistically dead even (crudely favored 40/15, not SS)

View attachment 323598

Cosmesis: SS favored hypofractionation significantly

View attachment 323599

Many more patients that Whelan, at least equal tumor control, impressive improvement in cosmesis, boost allowed. New standard? Improvement on Whelan?


FAST FORWARD: 4096 women, 1:1:1 rando to 40/15, 27/5, or 26/5. 5 year follow up.

Local control: dead even

View attachment 323600

Cosmesis: Clearly worse for 27/5, somewhat comparable for 26/5 vs 40/15, but some factors superior for 40/15

View attachment 323601

As @scarbrtj has said, the therapeutic window for radiotherapy can be annoyingly small. Seriously, 1Gy makes the difference?? Also, to @evilbooyaa credit, the brits were way too willing to gloss over some of the differences between 40/15 and 26/5 in issues such as breast induration, telangiectasia, and breast/chest wall (o)edema to further their agenda of decreased utilization.


SUMMARY

Whelan: was a practice changing study and remains a go to standard in US and Canada. Same outcome, less treatments.

START B: essentially one less fraction than Whelan, replicated Whelan otherwise and proved no detriment in tumor control with improved cosmesis. Allowed boost which is a bit of a confounder. We know boost is detrimental to cosmesis.

FAST FORWARD: 40/15 still looked like the winner to me. And shocking difference between 27/5 and 26/5. If one gray can make all the difference is this large phase 3 study, couldn't an additional 2.6 Gy fraction of whole breast radiation be the difference maker in cosmesis between 40/15 and 42.56/16?

FINAL TAKEAWAYS:

- I have no life and like to ponder pathetic questions like whole breast in 15 vs 16
- There might be a small toxicity difference between the two and given the scale of the diagnosis and treatment, its worth considering further even if it seems too basic
- If you are looking for the cleanest data without a boost, its Whelan
- If you want to boost, consider 40/15 as the whole breast portion
A 15 vs 16 discussion over side effects is not pathetic. It’s just too hard to get a handle on because it really is impossible to do between-trial comparisons when they’re conceived and carried out so differently. So it just becomes a The Dude “that’s like your opinion man” thing. On paper, 40/15 will be less BED3 than 42.5/16 (TBH I always use 42.4/16!). But when I do 42.4/16 I am anal retentive and do 3D wedging (aka IMRT) and just have random very small pockets >105% Rx throughout the breast. Compare that where you might just use wedges and a non modulated beam and have half the breast getting >105% or more using somewhat older school approaches. A 40/15 plan with “traditional” inhomogeneity vs a 42.4/16 plan with optimized and hand tweaked fluences... to the eye, just looking at absolute Gy doses and isovolumes, a 42.4 plan could look equivalent or better than 40, depending on the planner. As such it’s hard to be strident about 15 vs 16 as they are quite close in dose at the end of the day. However in general yes there’s mounting data that the therapeutic window in breast is “annoyingly small.” Hence why I am not rah rah booster. And why there’s no way in hell I’d treat this lady’s IMNs e.g.

TL;DR the devil’s in the dosimetric details
 
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We give 15 x 2.66 Gy and then add a boost (when indicated) of 4 x 2.66 Gy.
If there are quite alot of "negative" factors (G3, L1, margins rather close) we give an extra boost-fraction --> 5 x 2.66 Gy.
So I guess we compensate for a bit less dose of WBRT by giving a bit more dose of boost (4 x 2.66 Gy > 5 x 2 Gy).
 
I still can't stand this 26/5 and 27/5 trial design approach, or 28.5/5 and 30/5. It's intellectually dishonest. We're designing trials with two hypofrac arms, which in turn allows us to increase the odds of a statistical error, naturally favoring hypofractionation as a concept, which is the goal. Obviously, there was a statistically different result in the highest dose, and not lowest, arms in both FAST and FAST-FORWARD. OTOH, the more fractionated courses were numerically superior in both, suggesting that a larger trial will show inferiority, or not non-inferiority, of the 5 fraction course wrt toxicity. Problem is, now that the trial designers, and funders (National Institute for Health Research Health Technology Assessment Programme) got the answers they wanted, there's really no interest in the truth.
 
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I still can't stand this 26/5 and 27/5 trial design approach, or 28.5/5 and 30/5. It's intellectually dishonest. We're designing trials with two hypofrac arms, which in turn allows us to increase the odds of a statistical error, naturally favoring hypofractionation as a concept, which is the goal. Obviously, there was a statistically different result in the highest dose, and not lowest, arms in both FAST and FAST-FORWARD. OTOH, the more fractionated courses were numerically superior in both, suggesting that a larger trial will show inferiority, or not non-inferiority, of the 5 fraction course wrt toxicity. Problem is, now that the trial designers, and funders (National Institute for Health Research Health Technology Assessment Programme) got the answers they wanted, there's really no interest in the truth.
One thing I somewhat wistfully lament as we ponder the big clinical differences (in theory) that tiny differences in breast Rx dose can have is that the Harris-y (not heresy) of something like 45/25 WBI was never tested against 42.5 or 40 hypofx.
 
I get this is important, I truly do, but again there is a war going on and we are arguing about which boots to put on.
 
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TL;DR the devil’s in the dosimetric details
Want to delve into this a bit further. There is a huge variability between two potential breast plans. I push for max hot spot < 107%, keep 105% out of the inframammary fold, and push for a V105 < 5%, definitely less than 10%, on all breast plans. This includes the breast/chest wall aspect of a 3-field plan.

While I think Rx dose is a consideration as documented by @radmonckey (and I may be considering a switch to 40.05/15 for my WBI patients that need a boost) , I do think old school planning where like 33-50% of the breast was getting> 105% and max hot spots in the 115-120s being common may be a factor in some of these toxicity rates.

Thanks for the deep dive on FAST-FORWARD. I had not broken down each individual toxicity like that but will be mentioning it as a footnote in future discussions (I currently only offer it to those who I think don't have the best 5-year
 
Want to delve into this a bit further. There is a huge variability between two potential breast plans. I push for max hot spot < 107%, keep 105% out of the inframammary fold, and push for a V105 < 5%, definitely less than 10%, on all breast plans. This includes the breast/chest wall aspect of a 3-field plan.

While I think Rx dose is a consideration as documented by @radmonckey (and I may be considering a switch to 40.05/15 for my WBI patients that need a boost) , I do think old school planning where like 33-50% of the breast was getting> 105% and max hot spots in the 115-120s being common may be a factor in some of these toxicity rates.

Thanks for the deep dive on FAST-FORWARD. I had not broken down each individual toxicity like that but will be mentioning it as a footnote in future discussions (I currently only offer it to those who I think don't have the best 5-year
In my experience, being really picky... I offer “artisanal” breast planning (in my own mind!)... pays off in clinic (therapists notice), less hassle in life (patients bother you less), and more referrals and complements from the surgeons. The IMRT randomized breast experiences showed homogeneity counts.
 
I am really struggling to think about something I care less about than 16 fx + 4 versus 15 fx + 5 in breast cancer. Spending any energy on this is really the worst.
 
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I am really struggling to think about something I care less about than 16 fx + 4 versus 15 fx + 5 in breast cancer. Spending any energy on this is really the worst.
The big news this year, bolstered by covid and the need to expedite treatment, were the results of a trial comparing 26 Gy to 27 F#cking Gy, which came shortly after a trial comparing 28.5 G*ddam Gy to 30 motherf%cking Gy.. This is what we do.
 
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The big news this year, bolstered by covid and the need to expedite treatment, were the results of a trial comparing 26 Gy to 27 F#cking Gy, which came shortly after a trial comparing 28.5 G*ddam Gy to 30 motherf%cking Gy.. This is what we do.
Were more than a few rad oncs back in the day who would ask “How do you give 42.5 in 16? Is that 2.66 or 2.67 a day?” And I would say “it doesn’t matter.” And they’d say “Well I just want to do it exactly as in the trial.”

Rad oncs are such angels. Angels dancing on the head of a pin.
 
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I am really struggling to think about something I care less about than 16 fx + 4 versus 15 fx + 5 in breast cancer. Spending any energy on this is really the worst.

Then feel free to ignore this thread and post in the other threads that tickle your fancy.
 
Want to delve into this a bit further. There is a huge variability between two potential breast plans. I push for max hot spot < 107%, keep 105% out of the inframammary fold, and push for a V105 < 5%, definitely less than 10%, on all breast plans. This includes the breast/chest wall aspect of a 3-field plan.

While I think Rx dose is a consideration as documented by @radmonckey (and I may be considering a switch to 40.05/15 for my WBI patients that need a boost) , I do think old school planning where like 33-50% of the breast was getting> 105% and max hot spots in the 115-120s being common may be a factor in some of these toxicity rates.

Thanks for the deep dive on FAST-FORWARD. I had not broken down each individual toxicity like that but will be mentioning it as a footnote in future discussions (I currently only offer it to those who I think don't have the best 5-year
Are there any data on V105 correlating with toxicity in chest wall RT? The UPMC study was in intact breast.
 
Are there any data on V105 correlating with toxicity in chest wall RT? The UPMC study was in intact breast.

Good question. Not that I am aware of.

The UPMC study was in women with a larger breast, but I extrapolate it to all intact breasts and chest wall patients. It's at times tougher to achieve in CW patients depending on anatomy so I do relax a bit compared to simple WBI, but those are at least the goals I give to dosimetry.
 
Are there any data on V105 correlating with toxicity in chest wall RT?
One way to rephrase this, which tangentially goes back to what radmonkey was trying to say (that 42.5, which is 6% more dose than 40, has more risk of side effects), is "Are there any data that higher absolute doses to larger volumes increase toxicity?" All cells residing in isovolumes that are at 105% Rx dose have ~5-6% 5.4-6.3% more chance of acute and late XRT effects than cells residing in isovolumes at 100% Rx dose. Or so we have been taught.
 
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Good question. Not that I am aware of.

The UPMC study was in women with a larger breast, but I extrapolate it to all intact breasts and chest wall patients. It's at times tougher to achieve in CW patients depending on anatomy so I do relax a bit compared to simple WBI, but those are at least the goals I give to dosimetry.
I understand the extrapolation to smaller breasts, but do you think it's possible to extrapolate it to the chest wall? I'm not so sure but am open to being convinced. For one, using a bolus or lack thereof, or hypofractionation vs conventional, will impact toxicities much more than an extrapolated dosimetric goal that's unvalidated in the CW setting.
 
I understand the extrapolation to smaller breasts, but do you think it's possible to extrapolate it to the chest wall? I'm not so sure but am open to being convinced. For one, using a bolus or lack thereof, or hypofractionation vs conventional, will impact toxicities much more than an extrapolated dosimetric goal that's unvalidated in the CW setting.

True, and in fairness, I am not hypofractionating vast majority of my CW's (because 99% of the time are 3-fields) so perhaps for me it is mostly a moot point.

But I still shoot for those V105 and V110 goals even with standard frac. It's my own version of ALARA. No downside to asking for it. Won't push me to sliding window IMRT if I can't achieve it, FWIW.
 
True, and in fairness, I am not hypofractionating vast majority of my CW's (because 99% of the time are 3-fields) so perhaps for me it is mostly a moot point.

But I still shoot for those V105 and V110 goals even with standard frac. It's my own version of ALARA. No downside to asking for it. Won't push me to sliding window IMRT if I can't achieve it, FWIW.
I hear you. And just an FYI during the pandemic it might be worth offering hypofractionation to motivated patients based on the Chinese randomized trial - all of which were also 3 fields
 
I hear you. And just an FYI during the pandemic it might be worth offering hypofractionation to motivated patients based on the Chinese randomized trial - all of which were also 3 fields

Yes, we were offering it at start of COVID-19, but PMRT in Chinese trial was done using electrons for CW, 2D planning, and didn't cover IMNs, none of which is part of my practice, and thus I have concerns about ability to extrapolate to a US popoulation for all comers. I do still offer it to patients, mentioning those caveats, and that I would not consider SOC (yet, likely to change in next 5 years I imagine)
 
Yes, we were offering it at start of COVID-19, but PMRT in Chinese trial was done using electrons for CW, 2D planning, and didn't cover IMNs, none of which is part of my practice, and thus I have concerns about ability to extrapolate to a US popoulation for all comers. I do still offer it to patients, mentioning those caveats, and that I would not consider SOC (yet, likely to change in next 5 years I imagine)
Lots of patients getting 40/15 PMRT (and std fx too) in SUPREMO. To date, haven't heard there are problems. Although to be fair not sure there's been analysis in terms of fractionation/toxicity yet?
 
I've been freely irradiating nodes(Against scar's advise) in 16(!) fractions in WBI, and enrolling on Alliance for chestwalls (assuming plan for reconstruction).

Pandemic, mayne.
 
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Just going to throw this here. The trial used to be 40/15 vs standard frac, but you know how it goes...

 
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I've been freely irradiating nodes(Against scar's advise) in 16(!) fractions in WBI, and enrolling on Alliance for chestwalls (assuming plan for reconstruction).

Pandemic, mayne.

Wang from China has two separate trials in this space - the PMRT trial in Lancet Oncology, and this one (which I discovred more recently) for WBI + lymph nodes:


Can't see full paper now, but I assume fair number of those patients (given they enrolled N0-3) are N+ getting 3-field RT in 16 fractions, in a randomized trial.
 
Routinely doing 4 weeks for chest wall + regional nodes (including IMN). Extremely unlikely to go back to 6 weeks. They are tolerating it much better than conventional. I think when study is complete, the acute toxicity won't be the same - it will be reduced compared to traditional 1.8-2.0 Gy/Fx.

Another boon for patients and tragedy for our field.
 
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One overlooked nuance (not really a nuance; more an elephant in the room)...

Isn't it time to abandon whole breast irradiation for most patients? For (essentially) all my low risk patients, I do 42.4/16 whole breast, vs 40/15 whole breast, vs 15+5, blah blah blah. But this data's getting a little long in the tooth. Decreasing fractions is a flashy thing we can do on paper, and if you don't want booted out of the rad onc tribe you'd better be doing it. It can reduce a complex medical decision down to a couple of numbers: total dose and fractions. But volume is just as important, or more important, in determining XRT side effects and "QOL convenience" for patients. Right? So maybe it is time. The WBI discussion (and "boost" especially) is moot and old school. Any low-risk patient (which, again, most are) that I was confident about re: using hypofx WBI, I think it's time to use @radmonckey's "dose," but IMPORT LOW's volumes. (In a more perfect world I'd go to 5 fraction partial breast, but the world is not perfect yet.)

Accelerated Partial Breast Radiation: Information on Dose, Volume, Fractionation, and Efficacy from Randomized Trials

 
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5 fx APBI is beautiful. Patients very happy. Side effects maddeningly low, both acute and late. With regards to oncoplastic surgery, this makes it tricky. Since many people won't even boost in this scenario, then PBI would make very little sense. However, if people feel comfortable boosting a specific patient after oncoplastic surgery, then they should have been comfortable doing external beam APBI on that same patient. I wouldn't be confident delineating a cavity and Biozorb appears to annoy many surgeons, so conventional most likely for them (42/16 or 40/15, +/- boost .. the discussion above is so esoteric and so rad onc, essentially meaningless to patients and referrings alike, God bless us).

SDN hero, the LeBron James of Rad Onc job market predictions, utilizes 5 fraction whole or partial for a vast majority of his early stage patients. His PBI volume is substantially different than Livi (significantly smaller), so I would think his cosmetic outcome would be even better (but curious to note what recurrence rate will be in 10 years).

I was initially surprised how much more quickly Livi was adopted vs IMPORT Low. Actually, maybe not, since VMAT+DIBH+IGRT may mitigate the loss of charge due to reduced fractions.
 
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I have been hearing the argument about how "difficult" it is to delineate post oncoplastic surgery, however:

a) from my understanding oncoplastic surgery does not shift the surgical bed per se, but rather shifts other portions of the breast into the surgical bed
b) biozorb may not be availanle everywhere, but clipping the surgical bed should not be an issue for any surgeon, I think Livi utilized 4 clips
c) if oncoloplastic surgery is so much of an issue in terms of not being able to locate the tumor bed for EBRT, shouldn't we be seeing higher recurrence rates post oncoplastic surgery than post "standard" BCS, bearing in mind that all those boosts we have been delivering would then be off-target?
 
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I have been hearing the argument about how "difficult" it is to delineate post oncoplastic surgery, however:

a) from my understanding oncoplastic surgery does not shift the surgical bed per se, but rather shifts other portions of the breast into the surgical bed
b) biozorb may not be availanle everywhere, but clipping the surgical bed should not be an issue for any surgeon, I think Livi utilized 4 clips
c) if oncoloplastic surgery is so much of an issue in terms of not being able to locate the tumor bed for EBRT, shouldn't we be seeing higher recurrence rates post oncoplastic surgery than post "standard" BCS, bearing in mind that all those boosts we have been delivering would then be off-target?
Could just be like me and overcontouring seromas to account for ‘uncertainty’. Starting to see more women getting those types of operations, and it’s been tricky! Not sure what the solution is, but still getting experience on my end with what their ’appearances’ are.
 
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I have been hearing the argument about how "difficult" it is to delineate post oncoplastic surgery, however:

a) from my understanding oncoplastic surgery does not shift the surgical bed per se, but rather shifts other portions of the breast into the surgical bed
b) biozorb may not be availanle everywhere, but clipping the surgical bed should not be an issue for any surgeon, I think Livi utilized 4 clips
c) if oncoloplastic surgery is so much of an issue in terms of not being able to locate the tumor bed for EBRT, shouldn't we be seeing higher recurrence rates post oncoplastic surgery than post "standard" BCS, bearing in mind that all those boosts we have been delivering would then be off-target?

The always reasonable and logical European. I LIIIKE, VERY NIIIIIICE!
 
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Oncoplastic surgery w/ clips and/or biozorb = can do boost or APBI. Fortunately (for me) this is still a rare situation, but the ones I have seen do not have any markers of the cavity location. If I saw a lot of breast wiht a lot of oncoplastic surgery then I'd push harder to get surgeons to change practice for me.

When combined with a lack of 3-Dimension imaging for many of these patients (Breast MRIs not 100%, CT-staging not 100% given lack of necessity in early stage disease), it makes delineation difficult.

I don't boost if I don't see a seroma cavity or clips. Same for APBI.

APBI is certainly great for patients, both for convenience and seemingly less toxicity (all I can comment on personally is acute) but I've also seen some very large seroma cavities in comparison to breast size that have made me lean towards WBI or IMPORT-LOW PBI rather than my preferred regimen, of Livi.
 
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Oncoplastic surgery w/ clips and/or biozorb = can do boost or APBI. Fortunately (for me) this is still a rare situation, but the ones I have seen do not have any markers of the cavity location. If I saw a lot of breast wiht a lot of oncoplastic surgery then I'd push harder to get surgeons to change practice for me.

When combined with a lack of 3-Dimension imaging for many of these patients (Breast MRIs not 100%, CT-staging not 100% given lack of necessity in early stage disease), it makes delineation difficult.

I don't boost if I don't see a seroma cavity or clips. Same for APBI.

APBI is certainly great for patients, both for convenience and seemingly less toxicity (all I can comment on personally is acute) but I've also seen some very large seroma cavities in comparison to breast size that have made me lean towards WBI or IMPORT-LOW PBI rather than my preferred regimen, of Livi.

Nearly all the lumpectomies in our city done by fellowship-trained breast surgeons are now oncoplastic, and patients have been seeking out these breast surgeons. Getting the breast surgeons to stop doing oncoplastic surgeries is an absolute non-starter- they love doing them. Trying to change their practice there would result only in the patients getting routed to another radonc. There's almost never any seroma, and while the cavity can be clipped for a boost somewhat, I would never be comfortable enough to do 5-fx APBI.
 
Nearly all the lumpectomies in our city done by fellowship-trained breast surgeons are now oncoplastic, and patients have been seeking out these breast surgeons. Getting the breast surgeons to stop doing oncoplastic surgeries is an absolute non-starter- they love doing them. Trying to change their practice there would result only in the patients getting routed to another radonc. There's almost never any seroma, and while the cavity can be clipped for a boost somewhat, I would never be comfortable enough to do 5-fx APBI.
Is the concern the fractionation or the volume. The volume, right? Should we be comfortable enough to do 15 fx PBI? We can have a good idea where the “cavity” and previous tumor is/was. Put a good inf/sup margin on that and do mini tangents. Less than WBI (less scatter and direct dose to heart and lung and contralateral breast tissue eg) and will have less side effects.
 
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Mini tangents is exactly what IMPORT LOW did anyway, right?
 
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Nearly all the lumpectomies in our city done by fellowship-trained breast surgeons are now oncoplastic, and patients have been seeking out these breast surgeons. Getting the breast surgeons to stop doing oncoplastic surgeries is an absolute non-starter- they love doing them. Trying to change their practice there would result only in the patients getting routed to another radonc. There's almost never any seroma, and while the cavity can be clipped for a boost somewhat, I would never be comfortable enough to do 5-fx APBI.

They must bill a good bit more for these oncoplastic surgeries. Have seen my fair share of ladies with T1a-b tumors that are pushed into getting them for seemingly no reason.
 
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Nearly all the lumpectomies in our city done by fellowship-trained breast surgeons are now oncoplastic, and patients have been seeking out these breast surgeons. Getting the breast surgeons to stop doing oncoplastic surgeries is an absolute non-starter- they love doing them. Trying to change their practice there would result only in the patients getting routed to another radonc. There's almost never any seroma, and while the cavity can be clipped for a boost somewhat, I would never be comfortable enough to do 5-fx APBI.
Agree with this
Who would have thought that radonc may be partially saved by pelvic node radiation for prostate cancer and oncoplastic breast surgery

from livi 5 fraction trial median ptv was 111cc and max was 277cc. I’ve not seen any patient with oncoplastic surgery where a 1.5-2cm expansion around clips would yield a volume less than 277cc.
 
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