APBI - 26 Gy?

[SneakyBooger]

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I would love to get a good argument going as to whether 26 Gy in 5 fractions partial breast is valid for all 50+ yos with T1N0 favorable risk breast cancer.

Makes sense to me.

 

[RADONC4285]

It's probably fine. If 26/5 is good enough for whole breast, why wouldn't it be for partial breast? It's reasonable, especially if oncotype is low. Pretty sure there is an ongoing Canadian trial testing 27/5 partial breast. Having said that, why not stick to 30/5 since we have great long term data for it? The toxicity is so low, so I usually stick to it. If the cavity is very superficial or quite large and there is an issue meeting constraints, I skimp on coverage a little knowing that 26 Gy is probably all that's needed

 

[sirspamalot]

Does hormonal status play a role in your decision making whole vs partial?

Some women who refuse (or find out they can't tolerate) endocrine therapy may (?) benefit from whole breast..

 

[Palex80]

Does hormonal status play a role in your decision making whole vs partial?

Some women who refuse (or find out they can't tolerate) endocrine therapy may (?) benefit from whole breast..

I wouldn't do PBI in TNBC.

But if you are asking if I would change my mind on PBI vs. WBRT based on the decision of the patient to take or not take endocrine therapy, I do discuss that without WBRT and endocrine therapy, the risk of in-breast-recurrence will be higher.
I often quote the IBTR calculator.

https://www.tuftsmedicalcenter.org/ibtr/

 

[grenz]

I would probably expand the traditional Florence CTV out another 5mm since the 26Gy Isodose line in Florence could be treating microscopic disease

 

[RadOncDoc21]

Breast doses, volumes and fractionations… I’m sure we’ll find a consensus!

 

[sirspamalot]

 

[TheWallnerus]

Man that was an old statement by me above. I promise I did not urge the 'Boog to post it!

The 10y IMPORT-LOW results were a late-breaking abstract at ASTRO. About 3% in-breast failure rate at 10y... HR 0.99 vs whole breast. And the rate of late normal tissue effects (~5%) was about 6 times less than that of (40 Gy/15 fx) whole breast at 10y (~30%). That plus FAST-Forward results equals: almost all women who are older and have favorable risk breast cancer should just get partial breast radiotherapy, and the oncologic radiobiology of 5 fractions has been proven equal that of 15 fractions. Thus, 26 Gy in 5 fx should be the CLEAR standard for a 70yo with a T1bN0 ER+ tumor. While we can quibble over 5 vs 15 maybe, there is just no doubt now that more older women are harmed than helped who have T1N0ER+ breast cancer when receiving whole breast RT instead of partial breast RT.

What is a "dangerous" rad onc? To me, a dangerous rad onc is one who gives a treatment that is proven to have more side effects with proven zero increased survival or local control. I said it! (Below, "NTE" equals normal tissue effects.) Also, let's face it, the percentage of women who promise endocrine therapy non-compliance is low, and for now we all have to practice in harmony with our med onc sistren and brethren.

 

[sirspamalot]

is PBI billed as SBRT?

If not, say goodbye to radonc financial survival... 33 to 16 to 5 to 0.

#thisisthewayto0


ps. I chuckled at the one person who disliked this post. Hey, it ain't me fraction shaming and promoting nonsense. Spend that downvote on something where its deserved bro.

 

[Fpg1245]

is PBI billed as SBRT?

If not, say goodbye to radonc financial survival... 33 to 16 to 5 to 0.

#thisisthewayto0

Yeah so…won’t be doing that until that’s a thing. I remember asking about it with fellow colleagues and was immediately accused of being a fraudster so good luck with that.

 

[RickyScott]

I don’t treat breast, but if I did, I would offer partial breast 15 x 266 to these women solely for financial reasons.

 

[JustAdocInBox]

I don’t treat breast, but if I did, I would offer partial breast 15 x 266 to these women solely for financial

From a wRVU stand point 5 fx imrt is not all that different from 3 week 3D

 

[RickyScott]

From a wRVU stand point 5 fx imrt is not all that different from 3 week 3D

I thought 3D actually had more rvus? Anyway, I don’t need the rvus, if the clinic is routinely finishing by 1-2, hospital wont keep me as FTE and techs won’t get their 40 hrs.
I Don’t get too focused on rvus. I have a ton of rvus, but the hospital know they can replace me very quickly, probably with someone smarter and cheaper. Supply and demand is all that counts.

 

[yesmaster]

I do mostly 5 fx imrt apbi or occasionally 15 fx imrt apbi for low risk, stage 1A, luminal A patients.

It’s different than prostate where side effects similar or worse for hypofractionation, apbi is just better than whole breast.

My center’s large enough that it won’t close, but if we don’t hire anybody and stay at our current # of FTE’s for the next 10-20 years because we’re not doing 25-33 fx, all the better.

 

[sirspamalot]

but the hospital know they can replace me very quickly, probably with someone smarter and cheaper.

Then again, if you're in a rural 'nuff location and nobody wants to work here.. then you have job security. Not because you're good, or cheap. But because without you, its a big fat zero.

I can't even get vacation coverage properly for cryin' out loud.

 

[sirspamalot]

Yeah so…won’t be doing that until that’s a thing. I remember asking about it with fellow colleagues and was immediately accused of being a fraudster so good luck with that.

So we're clear, I don't recommend anyone do anything without understanding their own situation and speaking with appropriate professional advisors.

If you don't offer 5 fraction breast, you don't have to worry about it.

 

[sirspamalot]

SCENE

Group of angry finger pointing radoncs, mostly academics, clustered and shouting at each other.. fraction shaming galore..

"I'll give 15, instead of 16"

"I'll see your 15, and lower it to 6"

"I can beat your six, and counter with a FIVE!"

"I see your FIVE, and counter with ONE!" with chest thrusted forward spoketh the proud lone radonc.. glaring at the others...

BUT

Distinguished Medonc proudly steps forward and speaketh:

"Gentlemen, no need to outdo each other. We've arrived, now take your filthy photons and kindly exit the building. We won't be needing your services. Good day sirs."


And so, in the great book of Breast Radiation Oncology, it was written.

END SCENE

 

[evilbooyaa]

I prefer 30/5 rather than making up a fractionation scheme like 26/5 PBI. But others are welcome to do what they'd like. Just hope none of your 26/5 folks recurs locally. I prefer PBI for all patients who are candidates for PBI over WBI.

VMAT. Consider feasibility of billing as SBRT. The fact we're unwilling to consider it SBRT is our specialty's auto-schadenfreude

 

[Bequerel]

common sense says that if 26/5 ok for whole breast then it’s ok for apbi doesn’t it? But then again, I tried arguing the same type of common sense logic with my breast attendings in 2011 about hypofrac and dcis and they looked at me like I was crazy.

I personably do 30/5 when possible but have low threshold to lower to 26/5 with smaller breast volumes, close to nipple or skin or other scenarios where I want to reduce chances of toxicity.

 

[TheWallnerus]

I prefer 30/5 rather than making up a fractionation scheme like 26/5 PBI

Oh my. That's silly! You're not silly 🙂 26/5 is *not* a made up scheme.

Also, I'd just like to point out... about 10 or so more years ago, we considered 15-16 fractions "accelerated." Interesting how yesterday's "accelerated" is today's "standard."

NEVER FORGET.

 

[sirspamalot]

0 is the number.... And the number was zero....

 

[RickyScott]

SCENE

Group of angry finger pointing radoncs, mostly academics, clustered and shouting at each other.. fraction shaming galore..

"I'll give 15, instead of 16"

"I'll see your 15, and lower it to 6"

"I can beat your six, and counter with a FIVE!"

"I see your FIVE, and counter with ONE!" with chest thrusted forward spoketh the proud lone radonc.. glaring at the others...

BUT

Distinguished Medonc proudly steps forward and speaketh:

"Gentlemen, no need to outdo each other. We've arrived, now take your filthy photons and kindly exit the building. We won't be needing your services. Good day sirs."


And so, in the great book of Breast Radiation Oncology, it was written.

END SCENE

0 is the new 5.

Med’s Corey Speers notes that oncologists are trying to use less radiation when treating cancer | CWRU Newsroom | Case Western Reserve University

Radiation, a mainstay of cancer treatment, begins a fade-outRadiation, a mainstay of cancer treatment, begins a fade-outSTAT News: Corey Speers, a me...

thedaily.case.edu

 

[Fpg1245]

is PBI billed as SBRT?

If not, say goodbye to radonc financial survival... 33 to 16 to 5 to 0.

#thisisthewayto0


ps. I chuckled at the one person who disliked this post. Hey, it ain't me fraction shaming and promoting nonsense. Spend that downvote on something where its deserved bro.

The shame factory never shuts down.

 

[evilbooyaa]

Oh my. That's silly! You're not silly 🙂 26/5 is *not* a made up scheme.

Also, I'd just like to point out... about 10 or so more years ago, we considered 15-16 fractions "accelerated." Interesting how yesterday's "accelerated" is today's "standard."

NEVER FORGET.

View attachment 377500

26/5 is not made-up but 26/5 PBI is made-up and unstudied. When we have so much randomized data in early stage breast, I don't feel a need to go off the beaten path in terms of dosing.

common sense says that if 26/5 ok for whole breast then it’s ok for apbi doesn’t it? But then again, I tried arguing the same type of common sense logic with my breast attendings in 2011 about hypofrac and dcis and they looked at me like I was crazy.

I personably do 30/5 when possible but have low threshold to lower to 26/5 with smaller breast volumes, close to nipple or skin or other scenarios where I want to reduce chances of toxicity.

We have no confirmatory data that confirms that 26/5 to PBI volumes is oncologically equivalent to 26/5 WBI. It's overwhelmingly likely to be fine and I wouldn't hold up a case in chart rounds for doing it. But, unless someone has data that 26/5 PBI is less toxic and just as effective as 30/5 PBI I see no reason to go less than 30/5. Extrapolating IMPORT-low (which had bigger expansions than Florence regimen) across different fractionation schemes is, again, not unreasonable, but not necessary given we have such good data (IMO) from 30/5.
I think looking at cases individually and turning edges down to 26/5 if struggling with constraints is not unreasonable.

I don't like 26/5 WBI because it IS more toxic in certain domains, buried in the supplement, and glossed over by the UK authors as their goal is simply to reduce fractions because of the limitations of their own health system in regards to throughput of patients. It's not a huge difference, but it is LATE toxicity which is increased with 26/5 which I'm not OK with for my patients. Which is probably why UK ROs want to 26/5 PBI, knowing that 26/5 WBI is more toxic despite the conclusions of the UK study.

 

[deleted1111261]

Same logic as Evil
30/26 in 5, SIB
Can think of it as a very hot 26 Gy plan I suppose

 

[grenz]

26/5 is not made-up but 26/5 PBI is made-up and unstudied. When we have so much randomized data in early stage breast, I don't feel a need to go off the beaten path in terms of dosing.



We have no confirmatory data that confirms that 26/5 to PBI volumes is oncologically equivalent to 26/5 WBI. It's overwhelmingly likely to be fine and I wouldn't hold up a case in chart rounds for doing it. But, unless someone has data that 26/5 PBI is less toxic and just as effective as 30/5 PBI I see no reason to go less than 30/5. Extrapolating IMPORT-low (which had bigger expansions than Florence regimen) across different fractionation schemes is, again, not unreasonable, but not necessary given we have such good data (IMO) from 30/5.
I think looking at cases individually and turning edges down to 26/5 if struggling with constraints is not unreasonable.

I don't like 26/5 WBI because it IS more toxic in certain domains, buried in the supplement, and glossed over by the UK authors as their goal is simply to reduce fractions because of the limitations of their own health system in regards to throughput of patients. It's not a huge difference, but it is LATE toxicity which is increased with 26/5 which I'm not OK with for my patients. Which is probably why UK ROs want to 26/5 PBI, knowing that 26/5 WBI is more toxic despite the conclusions of the UK study.

You say the outcomes are good with 30/5, but has it been compared to 40/15 whole breast the way that IMPORT-LOW was (twice including DBCG)?

 

[deleted1111261]

You say the outcomes are good with 30/5, but has it been compared to 40/15 whole breast the way that IMPORT-LOW was (twice including DBCG)?

Hmm.
The outcomes are just so good with 30/5
Maybe some things just don’t have to be studied in breast cancer ??
Hahahaha. Kidding. Have to study the most tedious things and then still have no consensus

THIS IS THE WAY

 

[communitydoc13]

Do we expect 30/5 APBI to be worse than 26/5 APBI for local control?

Of course not.

It is a little bit better. Whether this is demonstrated in individual trials or not, I am sure that if we could run a trial on an infinite number of patients, there would be a few less recurrences in the 30 Gy arm.

Is the cosmetic outcome good? Yes, it is very good. Hard to improve on actually.

Is the lumpectomy bed hard? Yes, the lumpectomy bed gets hard after Livi.

So why are we dose de-escalating here? To reduce fibrosis at the lumpectomy bed? Not sure that is a good enough reason. Are we saving resources? Not really.

We are saving photons.

 

[TheWallnerus]

26/5 is not made-up but 26/5 PBI is made-up and unstudied

You should write a disapproving letter to the Royal College of Radiologists and/or His Majesty.

But think of the logic here. PBI is completely proven to be oncologically equivalent to whole breast for early stage low risk breast cancer; and also it is proven to be less toxic than whole breast. (And every time whole breast is treated, the part of the breast that would have been treated with partial breast has been treated.) And 26 Gy in 5 fractions whole breast is proven to be equivalent to a 3-week schedule of whole breast without increased toxicity.

To call 26/5 made-up and unstudied is obtusity. We don't have these kind of well-designed, well-sequenced, stepwise-logical trials, and data, anywhere else in radiation oncology. The START, IMPORT, and FAST studies, when viewed as cohesive whole, are the crown jewels (pun intended) of our breast radiotherapy EBM.

But, unless someone has data that 26/5 PBI is less toxic and just as effective as 30/5 PBI

You need data... you need to RUN A LARGE MULTI-INSTITUTIONAL TRIAL OF A THOUSAND WOMEN FOLLOWED FOR 10+ YEARS?... that 26 Gy is less toxic than 30 Gy?

 

[TheWallnerus]

Do we expect 30/5 APBI to be worse than 26/5 APBI for local control?

Of course not.

It is a little bit better. Whether this is demonstrated in individual trials or not, I am sure that if we could run a trial on an infinite number of patients, there would be a few less recurrences in the 30 Gy arm.

Is the cosmetic outcome good? Yes, it is very good. Hard to improve on actually.

Is the lumpectomy bed hard? Yes, the lumpectomy bed gets hard after Livi.

So why are we dose de-escalating here? To reduce fibrosis at the lumpectomy bed? Not sure that is a good enough reason. Are we saving resources? Not really.

We are saving photons.

ALARA 🙂

 

[sirspamalot]

#fractionshame #volumeshame

Sorry, hard pass for me.. literally.

 

[communitydoc13]

ALARA 🙂

I get that. But among the rationale for smaller treatment volumes in other disease sites is the corresponding ability to dose escalate for improved local control.

We have all this boost data that impacts local control. I'm not a big booster fwiw.

Is a (potentially) softer lumpectomy bed worth a 0.5% to 2% difference in recurrence?

I don't know.

 

[sirspamalot]

#soMANYjokes

 

[TheWallnerus]

#fractionshame #volumeshame

Sorry, hard pass for me.. literally.

I think it's important to remember in discussions like this: it's OK to shame an idea, but never a person. I love everyone!

Ideas:
1) There is zero data supporting the use of breast boost for breast hypofrac in general.
2) PBI is proven less toxic than whole breast.
3) "Shaming" the UK breast data because they have socialized medicine doesn't make a good argument against the data.

Eventually, I do foresee 5 fraction being the upper limit fractions allowed by insurance companies for early stage low risk breast cancer (almost all payors have a 21 fraction limit now... in the UK, about 80-90% of all breast cases are treated w/ 5 fx now). I could even see 5 fraction being the upper limit for all stages once the UK 5 fraction nodal data comes out, long-term. Insurance companies setting fraction limits will settle a lot of these arguments. I was upbraided by telephone by my residency PD around 2005 when she heard I had been doing a lot of 16 fraction breast treatments in practice... I felt the shame!

 

[deleted1111261]

Well

I was CERTAIN that 74 was better than 60 for lung cancer. Absolutely certain.

 

[OTN]

I think it's important to remember in discussions like this: it's OK to shame an idea, but never a person. I love everyone!

Ideas:
1) There is zero data supporting the use of breast boost for breast hypofrac in general.
2) PBI is proven less toxic than whole breast.
3) "Shaming" the UK breast data because they have socialized medicine doesn't make a good argument against the data.

Eventually, I do foresee 5 fraction being the upper limit fractions allowed by insurance companies for early stage low risk breast cancer (almost all payors have a 21 fraction limit now... in the UK, about 80-90% of all breast cases are treated w/ 5 fx now). I could even see 5 fraction being the upper limit for all stages once the UK 5 fraction nodal data comes out, long-term. Insurance companies setting fraction limits will settle a lot of these arguments. I was upbraided by telephone by my residency PD around 2005 when she heard I had been doing a lot of 16 fraction breast treatments in practice... I felt the shame!

Hold the phone...your residency program director called you to fraction-shame you after you graduated? HahahahahahahahaHAHAHAHAHA what a field we are in.

 

[medgator]

Hold the phone...your residency program director called you to fraction-shame you after you graduated? HahahahahahahahaHAHAHAHAHA what a field we are in.

In the wrong direction it sounded like.... 16 instead of 25-28

 

[HolySmokes]

1) There is zero data supporting the use of breast boost for breast hypofrac in general.

...there's zero data for 26/5 PBI but you're arguing it's reasonable based on oncologic principles. Which I agree with! But why would the same not be true for extrapolating a local control benefit for boost with hypofx?

 

[Ray D. Ayshun]

We're looking for a right answer when there isn't a wrong one. Unless you're doing 5 fx whole breast. Then you're wrong

 

[sirspamalot]

The only answer that will be accepted by the ever escalating need to one-up each other is zero.

 

[radiation123]

26/5 is not made-up but 26/5 PBI is made-up and unstudied. When we have so much randomized data in early stage breast, I don't feel a need to go off the beaten path in terms of dosing.



We have no confirmatory data that confirms that 26/5 to PBI volumes is oncologically equivalent to 26/5 WBI. It's overwhelmingly likely to be fine and I wouldn't hold up a case in chart rounds for doing it. But, unless someone has data that 26/5 PBI is less toxic and just as effective as 30/5 PBI I see no reason to go less than 30/5. Extrapolating IMPORT-low (which had bigger expansions than Florence regimen) across different fractionation schemes is, again, not unreasonable, but not necessary given we have such good data (IMO) from 30/5.
I think looking at cases individually and turning edges down to 26/5 if struggling with constraints is not unreasonable.

I don't like 26/5 WBI because it IS more toxic in certain domains, buried in the supplement, and glossed over by the UK authors as their goal is simply to reduce fractions because of the limitations of their own health system in regards to throughput of patients. It's not a huge difference, but it is LATE toxicity which is increased with 26/5 which I'm not OK with for my patients. Which is probably why UK ROs want to 26/5 PBI, knowing that 26/5 WBI is more toxic despite the conclusions of the UK study.

I would argue there is some randomized partial breast irradiation data that indicate doses lower than 30 gy in 5 fractions may decrease toxicity while maintaining high tumor control.

There is a phase II randomized controlled trial with 281 patietns that compared 27.5 Gy in 5 fractions to 30 Gy in 5 fractions. There was a trend to better cosmetic outcomes with 27.5 Gy. There were no local failures in either arm. Abstract attached below

 

[TheWallnerus]

In the wrong direction it sounded like.... 16 instead of 25-28

"In the old days" we were fraction shamed for doing too few fractions. Believe it or not.

 

[TheWallnerus]

...there's zero data for 26/5 PBI but you're arguing it's reasonable based on oncologic principles. Which I agree with! But why would the same not be true for extrapolating a local control benefit for boost with hypofx?

This is exactly true re: boost for hypofrac. Which is why I never boost 40 Gy in 15 fx whole breast, or partial breast. And here we have data, e.g., no extrapolation needed. The benefit of boost in START was a stone cold zero, something rather striking like an HR of 1.000 in "thousands" of women iirc.

 

[evilbooyaa]

I would argue there is some randomized partial breast irradiation data that indicate doses lower than 30 gy in 5 fractions may decrease toxicity while maintaining high tumor control.

There is a phase II randomized controlled trial with 281 patietns that compared 27.5 Gy in 5 fractions to 30 Gy in 5 fractions. There was a trend to better cosmetic outcomes with 27.5 Gy. There were no local failures in either arm. Abstract attached below

Great to see, I was not aware of this. Relevant data in this space.

A full publication would be nice.
Do we think 3-5 non-coplanar 3D (or IMRT) equal in toxicity risk to VMAT PBI as per Florence?

 

[sirspamalot]

Yup. No boost for whole breast 16 fx course.

AFAIK I don't recall a same quadrant failure.. ever...

 

[radiation123]

Great to see, I was not aware of this. Relevant data in this space.

A full publication would be nice.
Do we think 3-5 non-coplanar 3D (or IMRT) equal in toxicity risk to VMAT PBI as per Florence?

I agree a full publication would be nice. I believe that the abstact is almost two years old, so hopefully they will get a full publication out in the near future.

Thats a good point. I am curious how many patients where treated with 3D vs IMRT. I would likely guess that 3-5 non-coplanar IMRT would have very similar toxicity to VMAT. I am not sure about 3-5 non-coplanar 3D, my gut instinct is that the toxicity would likely be a little worse than VMAT.

 

[TheWallnerus]

Great to see, I was not aware of this. Relevant data in this space.

A full publication would be nice.
Do we think 3-5 non-coplanar 3D (or IMRT) equal in toxicity risk to VMAT PBI as per Florence?

I agree a full publication would be nice. I believe that the abstact is almost two years old, so hopefully they will get a full publication out in the near future.

Thats a good point. I am curious how many patients where treated with 3D vs IMRT. I would likely guess that 3-5 non-coplanar IMRT would have very similar toxicity to VMAT. I am not sure about 3-5 non-coplanar 3D, my gut instinct is that the toxicity would likely be a little worse than VMAT.

The heart (mean and max <1 Gy for most) and lung DVH generally can't be beat with a two-field partial breast IMRT tangent vs VMAT. Just sayin'.

 

[JustAdocInBox]

For post-op melanoma 27 in 5 (30 Gy in 5 but only evaluating coverage of the 90% IDL) has excellent local control. 30/5 is probably overkill for breast. I’m personally fine with 26 Gy in 5 APBI, most of these patients fall into the ever expanding pool of patients that are eligible for omission anyways.

 

[radiation123]

The heart (mean and max <1 Gy for most) and lung DVH generally can't be beat with a two-field partial breast IMRT tangent vs VMAT. Just sayin'.

View attachment 377511

Good point. I was thinking of skin toxicity when I replied. I am sure that two-filed partial breast IMRT tangent lowers heart dose and lung dose compared to VMAT, but I bet it is only slightly lower. I looked through a few of my 27.5 Gy partial breast patietns and as long as the tumor was not left sided and medial the mean heart dose was less than 1 Gy.

 

[TheWallnerus]

Good point. I was thinking of skin toxicity when I replied. I am sure that two-filed partial breast IMRT tangent lowers heart dose and lung dose compared to VMAT, but I bet it is only slightly lower. I looked through a few of my 27.5 Gy partial breast patietns and as long as the tumor was not left sided and medial the mean heart dose was less than 1 Gy.

Multi field or VMAT (acute, maybe even late) skin tox would be better vs two field tangent IMRT. Agree.