how will APM affect DIBH?

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How will APM affect DIBH and centers still looking to install DIBH hardware? Some of our centers don't yet have AlignRT purchased/installed. Would it make more sense for all centers to be equipped with AlignRT for DIBH, or just re-route left breast patients to the the existing AlignRT linac ...sort of like a "regional centre for left breast radiotherapy?" Thanks

 

[medgator]

How will APM affect DIBH and centers still looking to install DIBH hardware? Some of our centers don't yet have AlignRT purchased/installed. Would it make more sense for all centers to be equipped with AlignRT for DIBH, or just re-route left breast patients to the the existing AlignRT linac ...sort of like a "regional centre for left breast radiotherapy?" Thanks

For now, many payors who use evilcore require dibh to be used to pay for igrt. Plus you'll need for srs SBRT i would think

 

[Chartreuse Wombat]

If you are one of the "lucky" 30% that are "in" an APM zipcode the amount you are paid for breast cancer treatment is the same whether or not you use DIBH.

 

[evilbooyaa]

In OP's situation, I would not make extra expenses if patient care not going to suffer, and simply shuffle patient to 'DIBH center of excellence', all things else being equal. This is a delicate balance between patient convenience (closer to home vs not) vs financial considerations of the practice/hospital vs patient benefit (DIBH helps in *most* L-sided breast - although may not be considered mandatory in all of them however dependent on exactly what you're treating)

 

[medgator]

(DIBH helps in all L-sided breast)

Really?

 

[evilbooyaa]

Really?

I will change it to *most*. We can quibble over clinical benefit vs simply dosimetric benefit, but I've never seen a mean heart dose (on an individual patient) higher with DIBH than without.

 

[GI_RadOnc]

This question can be more generalized: "How does APM change capital expenses?" The answer is complicated: one has to measure direct and indirect referrals/new patients seen with purchase of the technology; along with philanthropy etc. There have been measurements of this with acaedemic proton centers: (Downstream Effect of a Proton Treatment Center on an Academic Medical Center - PubMed) but is very challenging to measure.

Anecdotally: we are in a well-served metro area and many women were asking about breath hold options; and when told that we didn't have them, went a few miles down the road to pursue it. DIBH was considered at the main site versus all sites; decision was made to all sites as post-mastectomy breast cancer patients still have long treatment courses and technical standardization is always nice; as well as that DIBH isn't that expensive.

I don't see anyone putting more expensive technology at all sites; especially for those with rapid radiation regimens (SRS/SBRT - anything that can be done in a week!). As many on this forum have commented; larger centers are incentivized to implement advanced technology to treat patients who are geographically further away from them.

IMHO: APM increases this incentivization.

 

[scarbrtj]

I will change it to *most*. We can quibble over clinical benefit vs simply dosimetric benefit, but I've never seen a mean heart dose (on an individual patient) higher with DIBH than without.

If all we are after is benefit-on-paper vs demonstrated benefit-in-real-life, DIBH beats non-DIBH. And protons beats DIBH. In regards to using some things in rad onc, re: IMRT e.g., people tripped over themselves saying IMRT shouldn't be used without demonstrated clinical evidence it was superior. You can make almost any plan, anywhere in the body, look better in silico with IMRT than without; if that's all that were necessary to justify its use, I'd use IMRT 100% of the time, even 8 Gy/1 fx bone mets. Guess this stringency doesn't apply to DIBH? As far as breast cancer patients going "DIBH shopping," were it described as "I'd like a treatment that is more expensive with no proven clinical benefit," I wonder if they'd still shop for it.

 

[fiji128]

In stage I type of patients prone can give excellent plans (mean heart <1 Gy) and require much less "tech". Of course you also have to buy that prone board separately but at least there is no costly software.

 

[scarbrtj]

In light of all the recent partial breast data, I've always been interested in an approach where the tangents excluded heart (and excluded more lung too) completely. That should be tested vs traditional tangents. The only reason tangents were so "deep" to start with is our obsession over CW coverage in early stage breast... a concept that has been wholly rendered moot IMHO.

 

[RadOncDoc21]

In light of all the recent partial breast data, I've always been interested in an approach where the tangents excluded heart (and excluded more lung too) completely. That should be tested vs traditional tangents. The only reason tangents were so "deep" to start with is our obsession over CW coverage in early stage breast... a concept that has been wholly rendered moot IMHO.

This is true, hence why breast is the only organ site (I know of) where we are allowed to “cheat” on our PTV coverage so much. I do “cheat” all the time in other sites in order to keep my dosimitrist happy!

 

[RickyScott]

This is true, hence why breast is the only organ site (I know of) where we are allowed to “cheat” on our PTV coverage so much. I do “cheat” all the time in other sites in order to keep my dosimitrist happy!

Ebrt Partial breast is legit phase 3 validated.
So no one should have an issue with blocking the heart unless cavity nearby.

 

[scarbrtj]

Ebrt Partial breast is legit phase 3 validated.
So no one should have an issue with blocking the heart unless cavity nearby.

That said, in the trial I tongue-in-cheek alluded to, they expressly attempted ~zero heart dose with their "mini-tangents" (vs traditional tangents). In the ~600 patients with traditional tangents, I think there was one "confirmed" case of RT-related heart problems in the traditional tangent group vs 0 in the mini-tangent group. (It's in the appendix; a recommended read.) Assuming these incidences from IMPORT LOW might match what we'd see with DIBH, i.e. ~0.1% heart disease risk in early stage breast without DIBH and ~0% risk with DIBH, you would need a study of approximately 7500 patients in each arm (N=15,000) to test DIBH's "worth" in early stage breast cancer re: heart disease.

In other words, the clinical benefit of DIBH in early stage breast is unprovable.

 

[drewdog1973]

I think most useful when treating IMNs. Not really useful for intact/N0 breast. When you go from MHD of 6 to 1, it probably matters. Study will never happen. Just use it!

 

[scarbrtj]

Just use it!

Of course this is a much more heard rallying cry on the "its" that reimburse vs those that don't 😉

 

[RadOncMegatron]

This is true, hence why breast is the only organ site (I know of) where we are allowed to “cheat” on our PTV coverage so much. I do “cheat” all the time in other sites in order to keep my dosimitrist happy!

During residency the average time it takes for this rule to be broken once learned by the resident is ~1 day

 

[scarbrtj]

During residency the average time it takes for this rule to be broken once learned by the resident is ~1 day

 

[evilbooyaa]

That said, in the trial I tongue-in-cheek alluded to, they expressly attempted ~zero heart dose with their "mini-tangents" (vs traditional tangents). In the ~600 patients with traditional tangents, I think there was one "confirmed" case of RT-related heart problems in the traditional tangent group vs 0 in the mini-tangent group. (It's in the appendix; a recommended read.) Assuming these incidences from IMPORT LOW might match what we'd see with DIBH, i.e. ~0.1% heart disease risk in early stage breast without DIBH and ~0% risk with DIBH, you would need a study of approximately 7500 patients in each arm (N=15,000) to test DIBH's "worth" in early stage breast cancer re: heart disease.

In other words, the clinical benefit of DIBH in early stage breast is unprovable.

On all patients, I agree with you, re: clinical benefit. I do think there is a subset (medial cavity, treating IMNs, barrel chested with heart too much in the way) that have sufficient dosimetric advantage to warrant considering it clinically useful (like getting MHD down from > 4 to < 2).

I will admit that I was a bit of a snob during residency, especially during PGY-2/3 years, and was wary about referring out L breast cancers to facilities that didn't have DIBH.

I have learned and progressed from that as results of IMPORT-LOW showed that WBI can skimp along the medial aspect (as long as cavity not in that location) without issue. I do agree that it is mostly a marketing gimmick.

That being said, I've seen people accept MHD higher than I would accept (MHD of 4-5 on a L breast alone plan, cavity not medial with beam going through heart), but I realize that is more a disagreement with a person (the Rad Onc) than the technology (DIBH vs no DIBH).

 

[scarbrtj]

I will admit that I was a bit of a snob during residency, especially during PGY-2/3 years, and was wary about referring out L breast cancers to facilities that didn't have DIBH.

I may not come off like it now, but I was Lord Snob of Snoboslovia when I got out of residency. Your brief observation is one from which a lot of people could learn and grow.

 

[drewdog1973]

On all patients, I agree with you, re: clinical benefit. I do think there is a subset (medial cavity, treating IMNs, barrel chested with heart too much in the way) that have sufficient dosimetric advantage to warrant considering it clinically useful (like getting MHD down from > 4 to < 2).

I will admit that I was a bit of a snob during residency, especially during PGY-2/3 years, and was wary about referring out L breast cancers to facilities that didn't have DIBH.

I have learned and progressed from that as results of IMPORT-LOW showed that WBI can skimp along the medial aspect (as long as cavity not in that location) without issue. I do agree that it is mostly a marketing gimmick.

That being said, I've seen people accept MHD higher than I would accept (MHD of 4-5 on a L breast alone plan, cavity not medial with beam going through heart), but I realize that is more a disagreement with a person (the Rad Onc) than the technology (DIBH vs no DIBH).

Over a decade of PBI studies have had such good local control that many people stopped worrying, and began blocking out the heart years ago. If 90% of recurrences are within 2 cm, no reason to chase every bit of the parenchyma.

MHD of 4-5 Gy on intact breast/N0 is insane. How does that even happen? Don't people have scorecards? 5 Gy really shouldn't even happen when treating nodes.

 

[scarbrtj]

See. We are just skipping right over the DIBH. Proton guys & gals bringing back the 10-fx APBI. APM guys licking their chops over stuff like this. We will need a 15,000 patient trial to show heart benefits from protons vs 5 fx IMRT. We may need a million patient trial to show a benefit vs single dose IORT.

"We really don't recommend left sided breast RT unless it's protons" - Future rad onc, somewhere, right after he gets a proton machine

https://www.redjournal.org/article/S0360-3016(20)34277-2/pdf

 

[medgator]

"We really don't recommend left sided breast RT unless it's protons" - Future rad onc, somewhere, right after he gets a proton machine

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Isn't that pretty much what Nancy Lee said?

 

[thecarbonionangle]

See. We are just skipping right over the DIBH. Proton guys & gals bringing back the 10-fx APBI. APM guys licking their chops over stuff like this. We will need a 15,000 patient trial to show heart benefits from protons vs 5 fx IMRT. We may need a million patient trial to show a benefit vs single dose IORT.

"We really don't recommend left sided breast RT unless it's protons" - Future rad onc, somewhere, right after he gets a proton machine

https://www.redjournal.org/article/S0360-3016(20)34277-2/pdf

Besides left sided early stage breast, you can get beautiful plans on postmastectomy inflammatory breast. Great skin dose without bolus, they saying.

 

[kimplera]

you would need a study of approximately 7500 patients in each arm (N=15,000) to test DIBH's "worth" in early stage breast cancer re: heart disease.

In other words, the clinical benefit of DIBH in early stage breast is unprovable.

Not unprovable - just that there are a bunch of other studies you would have to forgo in order to get your answer to this question...

 

[RickyScott]

Not inconceivable that protons are worse. Only 2 rib fractures in breast I have ever seen were protons.

 

[Palex80]

Not inconceivable that protons are worse. Only 2 rib fractures in breast I have ever seen were protons.

Which fits well into the "higher RBE issue" at the far end of the Bragg-Peak!

 

[evilbooyaa]

Over a decade of PBI studies have had such good local control that many people stopped worrying, and began blocking out the heart years ago. If 90% of recurrences are within 2 cm, no reason to chase every bit of the parenchyma.

MHD of 4-5 Gy on intact breast/N0 is insane. How does that even happen? Don't people have scorecards? 5 Gy really shouldn't even happen when treating nodes.

I don't disagree, but I've seen it and it's usually a combination of a sleepy attending and a sleepy dosimetrist when it happens. And there are sometimes when the anatomy dictates that situation, along with tumor location.