5-day breast radiation probably a new standard

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RAPID showed worse cosmesis w/ EBRT ABPI w/ 38.5/10 BID.

But focusing on just B-39:
Full results of B-39 was presented at SABCS showing inability to claim oncological non-inferiority: Result Content View

The above abstract also says that PBI had worse G3 toxicity than WBI.

I don't see anything that supports the assertion that APBI is non-inferior to WBI. The study results hyperlink leads to this, which is just the PRO outcomes showing mixed toxicity results with APBI compared to WBI: Patient-reported outcomes (PROs) in NRG oncology/NSABP B-39/RTOG 0413: A randomized phase III study of conventional whole breast irradiation (WBI) versus partial breast irradiation (PBI) in stage 0, I, or II breast cancer. | 2019 ASCO Annual Meeting Abstracts

Is APBI a reasonable option? Sure, but we knew that already.

Is it, based on current evidence, going to replace hypofractionated WBI as the 'preferred' option for early breast? No. Could that change in the future? Sure. I also imagine most people on the fence about this are referencing EBRT APBI, not brachytherapy-based (Mammosite/SAVI/full interstitial,etc.)
 
Anecdotally, I have seen better outcomes with 30/5 than with 38/10 BID.

I have enrolled patients on B-39 as a resident and saw inferior cosmesis (we actually quit enrolling due to one or two bad cosmetic outcomes).

Then as an attending over the past few years have selectively used the Italian randomized IMRT technique of 30/5 and had much better cosmesis.

For small cavities in patients with ASTRO "suitable" criteria, I often do offer APBI as 30/5 now...especially for older patients. If the cavity or clips are a pretty large area (on the Italian trial they had a constraint about how much total breast dose there is...if I can't meet it...) and I'm still wanting partial breast for whatever reason, then I've used the UK IMPORT LOW schedule of 40/15.

In my experience the brachytherapy patients do OK as well, but that is largely surgeon driven. Some of the slides from the B-39 presentation at San Antonio did suggest possible worse local control with brachy...but I haven't seen full text breakdown. I don't think the data or outcomes are so good that I'm pushing some of my breast surgeons to jump into that game unless they're already doing it and enjoy it. I stick pretty strictly to ASTRO guidelines for brachy if the surgeon wants it though.
 
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38/10 BID is an overkill in terms of dose delivered. I never understood the rationale behind that dose schedule.
 
Agree. Results in rock-hard breast. I think this prescription was conceived in 1990's by Dr. Vicini and his group to "replicate" interstitial brachytherapy schedule. It was flawed thinking of course, since one can never re-create brachy effect by EBRT.

Palex80 said:
38/10 BID is an overkill in terms of dose delivered. I never understood the rationale behind that dose schedule.
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Let's say B-39, in which 20% of patients had APBI with brachytherapy as opposed to external beam, showed that brachytherapy APBI had twice the failure rate of whole breast with worse cosmesis, i.e. the only reason the outcomes presented thus far were comparable was due to the majority of patients having external beam APBI. Would anyone continue to offer brachy based APBI? Or maybe ASTRO will question if this is good for patients too.
 
Is that the case? Or you just speculating.

BruiservonWillebrand said:
Let's say B-39, in which 20% of patients had APBI with brachytherapy as opposed to external beam, showed that brachytherapy APBI had twice the failure rate of whole breast with worse cosmesis, i.e. the only reason the outcomes presented thus far were comparable was due to the majority of patients having external beam APBI. Would anyone continue to offer brachy based APBI? Or maybe ASTRO will question if this is good for patients too.
Click to expand...
 
seper said:
Is that the case? Or you just speculating.
Click to expand...

It has been outright stated by those involved in the trial that there were more "events" in the brachytherapy arm. It was unclear to me if this was referring to recurrence or toxicity, however, neither is good. Much time has been spent lambasting external beam APBI when in actuality, in this particular trial, it may have been the more preferable of the two.
 
We had an interesting case in the clinic today.
65 yo lady, status post pneumonectomy on the left side for NSCLC quite a few years ago, she‘s in complete remission.
She has currenthly undergone bilateral BCS for breast cancer.
Left side: adenoid cystic carcinoma pT2 pN0 clear margins.
Right side: pT1a (m) pN0 clear margins, ER/PR+ IDC G2. The (m) refers to two focii of invasive tumor, but there was quite a bit DCIS in the surgical specimen too.
She seems to have quite big breasts.

So my colleague presented the case and wanted to do bilateral whole breast RT.

My boss wanted to send her back for bilateral mastectomy, since she only has one lung and the heart is stuck under the chest wall of the left side, making ghe argument that mastectomy would spare her heart and single lung from RT dose. DIBH probably wont help with the heart, it seems to be stuck on that chest wall.
Seems like a good plan to me, if it was discussed at the start before any surgery, but apparently noone asked us back then.

I was thinking of doing whole breast for left (with tighter than usual constraints for heart) and no RT for right or perhaps PBI on the Linac for right, if the cavity wasn‘t huge. Mastectomy sounded to me like an overkill and would mean another surgery (for a patient with one lung), plus a quite big scar (big breasts) ––> potentially longer / second surgery for problems with wound healing?
Deferring or deescalating RT for right may put her in greater risk of local recurrence (she doesn‘t quite fit all the strict criteria for PBI with (m) and extensive DCIS), but probably will not change OS.

She seems to have been a heavy smoker.

Your thoughts?
 
Palex80 said:
Deferring or deescalating RT for right would put her in greater risk of local recurrence, but probably not change OS.
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***Definitely*** would not change survival one whit.
Palex80 said:
Left side: adenoid cystic carcinoma pT2 pN0 clear margins.
Click to expand...
Like for real adenoid cystic? That's gotta be rare. The ACC is on the left, as was the NSCLC? Did she get RT for that NSCLC? ACC in breast, radiation-induced malignancy my first thought. Is there a lot of data for post-lumpectomy RT for ACC of breast that;s low stage? I don't think so.

My gut thought is, no RT for this lady. Anti-E only, and wish her a nice life.
 
BruiservonWillebrand said:
Let's say B-39, in which 20% of patients had APBI with brachytherapy as opposed to external beam, showed that brachytherapy APBI had twice the failure rate of whole breast with worse cosmesis, i.e. the only reason the outcomes presented thus far were comparable was due to the majority of patients having external beam APBI. Would anyone continue to offer brachy based APBI? Or maybe ASTRO will question if this is good for patients too.
Click to expand...

If that is true I would analyze the data and likely immediately stop doing brachy based APBI in favor of EBRT APBI. My statements are extrapolations of previously published data that have shown that statement (such as the RAPID trial). If you have slides from Julia White's talk, I'd love to see them.

radmonckey said:
It has been outright stated by those involved in the trial that there were more "events" in the brachytherapy arm. It was unclear to me if this was referring to recurrence or toxicity, however, neither is good. Much time has been spent lambasting external beam APBI when in actuality, in this particular trial, it may have been the more preferable of the two.
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Is there a source for this? Or are we saying anecdotes of people involved in the trial? If that statement is truly the case, this is very valuable information that should be presented within the medical literature, ASAP.

I never understand what takes these things so long to go from abstract to paper. Is there no resident at one of the participating institutions that has the whole database and could crank out all these obviously relevant analyses and subset analyses in a time frame that isn't years??
 
@Palex80 would favor bilateral breast WBI, hypofractionated. Block the heart on the left completely with tangential beams. Shoot for mean heart dose < 4Gy. Not exactly sure how ACC histology changes things for the right breast; personally, would treat just like regular (without having done a lit search of breast ACC). For the left breast, IMPORT-LOW tells us doing PBI with hypofractionated regimen is likely fine, so doing slightly less than WBI should be fine too.

I'm assuming L Breast doesn't meet PRIME-II or RTOG 9804 criteria?

Agree that survival will be unaffected even if you omit RT, just differences in LR.
 
evilbooyaa said:
@Palex80 would favor bilateral breast WBI, hypofractionated. Block the heart on the left completely with tangential beams. Shoot for mean heart dose < 4Gy. Not exactly sure how ACC histology changes things for the right breast; personally, would treat just like regular (without having done a lit search of breast ACC). For the left breast, IMPORT-LOW tells us doing PBI with hypofractionated regimen is likely fine, so doing slightly less than WBI should be fine too.

I'm assuming L Breast doesn't meet PRIME-II or RTOG 9804 criteria?

Agree that survival will be unaffected even if you omit RT, just differences in LR.
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Hypofx RT for ACC of breast is a WAG. Potentially a bad WAG because there's data in other subsites that postop RT for ACC has definite dose response; ie, more dose, more LC. And, the histology of ACC gives us no indicator of its biology usually. Grading it really gives no indicator of its local recurrence risk (ie can look benign and then come back in a year after 60-66 Gy postop), and this makes me think the alpha/betas are VERY variable for ACC. Hypofx is dose-deescalation for higher alpha/beta tumors. I say all that to say, I would give 60 Gy conv fx postop for all ACCs regardless of subsites. All the hypofx breast data is for adeno's (or CISs maybe)... and you can't/shant apply that here IMHO. EDIT: And no WBI (why would you?) for ACC of breast; it's not the same regular 'ol bailiwick as breast adenoCA
 
If all ACC in all subsites is truly all the same (note that we don't say this about adenoCA, SCC, neuroendocrine tumors from various subsites), then I can get on board that the R Breast doesn't need RT. If this was my patient I'd probably do a lit search on breast ACC to see if it's really the same as all other ACC.
 
BruiservonWillebrand said:
Julia White gave a talk to the MD Breast Cancer Consortium two weeks ago. This was the data she presented.
Click to expand...

I've seen one screen shot of a slide at San Antonio from an exploratory analysis showing brachy failure ~7-8% versus APBD 3-D EBRT ~3-4%.

I haven't seen anything about a multivariate analysis or if there was any particular imbalance in the brachy population, etc. Haven't seen the full text/data, etc.

It's definitely got my antennae up though. I'm probably going to be doing more 30/5 or 40/15 partial breast for patients that I think may be good candidates.
 
As mentioned above, Julia White has alluded to this several times.

www.medscape.com

Randomized Data (Finally) on Partial Breast Irradiation

Drs Julia White and Kathy Miller discuss the informative and long-awaited results of the NSABP B-39/RTOG 0413 trial comparing whole vs partial breast irradiation.
www.medscape.com www.medscape.com

Requires Medscape login

"
Miller: Most of this was external beam. The set-up was similar to whole breast radiation but with different treatment planning.

White: Exactly. What is important—and it was not a planned analysis so I don't want to make too much of this, but—we have been asked so much in this trial [whether there] is a better method for partial breast irradiation. Quite honestly, we do see more event rates in the groups that got brachytherapy. Again, a minority of our patients [received brachytherapy]. But we feel more comfortable saying that the external beam is where we see fewer events. And it's what people have at access.
"
 
3D vs. MammoSite is surely the first subgroup analysis they're doing.

radmonckey said:
It has been outright stated by those involved in the trial that there were more "events" in the brachytherapy arm. It was unclear to me if this was referring to recurrence or toxicity, however, neither is good. Much time has been spent lambasting external beam APBI when in actuality, in this particular trial, it may have been the more preferable of the two.
Click to expand...
 
seper said:
3D vs. MammoSite is surely the first subgroup analysis they're doing.
Click to expand...

I hope so.

I have one breast surgeon that loves brachy. The others are ambivalent so I don't really push for it. I stick very strickly to ASTRO guidelines but I may have to pump the brakes if the data is compelling enough.
 
probiotic said:
Probably most patients in B-39 received ballon based brachytherapy. But multi-catheter interstitial brachytherapy is a totally different modality. Much larger target volume and relatively homogenous dose distriburation plus advantages of optimization. And we have strong evidence for that.

Click to expand...

Does anyone in the US actually do this? We use Savi for the few cases that come our way, but I am not that impressed with the ability to get a better looking plan. The only thing it is good for is getting dose off the chest wall or skin. The multichannel plans themselves actually tend to run hotter with more V150 V200 etc which one would think would negatively impact cosmesis. I typically run a single channel plan unless up against the skin or chest wall.
 
I think somebody at Harvard is still a big believer in multicatheter interstitial plans, in terms of US support.

But yeah, I would rather just 15-20 frac somebody rather than shish kebab their entire breast for a week.

In regards to MammoSite vs SAVI, V150/200 only matters if it's in the tissue, not if it's within the catheter or the balloon. I agree that for most cases it probably doesn't make a huge difference between the two.
 
evilbooyaa said:
If all ACC in all subsites is truly all the same (note that we don't say this about adenoCA, SCC, neuroendocrine tumors from various subsites), then I can get on board that the R Breast doesn't need RT. If this was my patient I'd probably do a lit search on breast ACC to see if it's really the same as all other ACC.
Click to expand...
The biggest 'N' I could find was this...
Trends of Radiation Therapy in Adenoid Cystic Carcinoma of the Breast—A National Cancer Database Study
Perhaps 40-50 cases of ACC breast per year in US. Seems to never recur in-breast away from tumor cavity. E.g. like other ACC's *very* local recurrences are de rigeur. Although when RT has been used it's 1) always been some form of whole breast+boost it seems, and 2) never been hypofx. LN mets are very rare at presentation. Lots more could be said... suffice to say, it's a weird beast/bit unpredictable. Certainly regarding ACC outside the breast, there is zero literature for the effectiveness of ~40-45Gy at ~2.5-2.7Gy a day. Again I think this is also true for inside the breast. If I crossed the Rubicon of RT in her, I would apply wide-margin RT only to left-sided tumor cavity to ~66Gy/33fx (a very good postop dose for ACC historically, also an acceptable breast boost dose) using non-coplanar IMRT holding whole breast in abeyance to weigh the benefit of RT against the risk of heart exposure vs a whole-breast-containing approach. *If* I irradiated. Especially if margins were clean,, and no perineural invasion were seen (which is seen in some cylindromas and perhaps a marker for LC), I would not. Palex... don't irradiate 🙂
 
scarbrtj said:
Like for real adenoid cystic? That's gotta be rare. The ACC is on the left, as was the NSCLC? Did she get RT for that NSCLC? ACC in breast, radiation-induced malignancy my first thought. Is there a lot of data for post-lumpectomy RT for ACC of breast that;s low stage? I don't think so.
Click to expand...
ACC left and NSCLC left. Status post pneumonectomy left side, no RT for NSCLC.
Not a lot of data for ACC of the breast. They do seem to metastasize less often.
 
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