Those two reasons I mentioned. Stationary and less RT, and because I can. There was an interesting retro study where IMN's were treated in right breast and not in left, and there was a high LR rate in the left breasts. I wonder if looking back, there's a different rate of recurrence in right breasts treated without breath hold vs left treated with. Maybe it's absurd, but the breast moves with respiration, and given the centrality of the PTV_eval to breast planning, I already feel like I'm looking in the other direction with every breast I plan and treat.
jamanetwork.com
www.medpagetoday.com
Please dont start this. I wish all breast people would go into a breast RO squid game and the “winners” decide breast policy in our field rather than having breast be the absolute worst, and most commonly failed section on orals.Does this year's ASTRO make anyone want to demur over IMNing as much
Effect of Elective IMNI on DFS in Women With Node-Positive Breast Cancer
This randomized clinical trial evaluates the effect of internal mammary node irradiation in regional nodal irradiation on disease-free survival among women with node-positive breast cancer in South Korea.
No Survival Benefit for Internal Mammary Node Irradiation in Breast Cancer
Women with medially or centrally located tumors may be candidates, however, says researcher
Standard for right sided tangents?
Not unless it is a dextrocardia pt which i hAve seen in chart rounds or some other unusual anatomy. For tangents only unless some other issue you likely do not need it. For RNI i would consider slam dunk
Main reasons would be that if its really only marginal you just increase the time on the machine and possibly discomfort to the patient if they have trouble holding their breath.
The answer to the question "who's mad at me today" is, >90% of the time, "the therapists", often because I asked them for a setup more complicated than "supine on the table, arms down".
Came here to say this - for tangents only, why not just treat prone? Gets rid of the skin fold too.
/tangent
Well... One can argue that there are cases where you wouldn't treat with RNI (cN0/pN0) but you wouldn't be comfortable doing IMPORT-LOW either. I am thinking about young, premenopausal patients with TNBC post-BCS and not ypT0, for instance. Would you treat them with PBI?
Yes I should not have said "literally." I should have said "almost literally."
The patient wouldn't really fit in IMPORT-LOW. But I think I literally have not seen a T1N0 44yo TNBC female get NAC and come see me since I recall switching to IMPORT-LOW routinely, which was probably around 2019. (Although wouldn't it be nice to have comfort/confidence to know we could eliminate hundreds of ostensibly normal tissue cc's of irradiated volume in a young patient.) I don't have to tell you it can cause steam to shoot out of your ears if you try to think hard about "Will a tumor coming back 3 inches from the tumor cavity in the breast be an important event in non-ypT0 TNBC or will the tumor coming back 30 inches away in another part of the body be the important event?"
Red journal podcast recently had an MDACC breast faculty on talking about PBI. I think they said that they do a fair amount of IMPORT-LOW there. Do you do it with mini-tangents?
I don't. I know that's what the trial did, but I will usually add an extra beam angle or two to make it more conformal. I do follow their margins and planning constraints.
This is probably fine. I always just do two-beam tangents. In America we have a problem with insurance companies that when they see "breast" and "15 fractions" they immediately disallow any IMRT approach. In their guidelines, the insurance companies specifically call Intensity Modulated Partial Organ RT not IMRT.We do VMAT for all APBI.
My thinking about DIBH for tangents has alot to do with what the plan looks like vs what happens in reality. We 4D most everything these days that might move a litte, yet I'm not aware of anyone doing this for breast and creating an ITV. We have a moving target that we pretend doesn't move. There's kinda been a look the other way approach to breast historically, which is probably just a product of realizing how little we're actually needed, but how important it is to staying employed. I'm wondering about right sided tangent DIBH mostly because, if I'm going to plan as if the target isn't moving, perhaps it'd be best if it doesn't.
Doubtful. George Chen and his guys at MGH studied this a ton back in the early days of IMRT when everyone was stupid frightened of IMRT for lung and moving targets. He showed how the IRL target dose gets to the TPS Rx dose, with good margins, after only a few fractions. Five fractions would push this assumption a little far but for 15 or more fractions... the dose to the moving target is reliable w/ dMLCs. In summary, motion is no more a big deal in fractionated IMRT than in fractionated 3DCRT.
I assume you're using some sort of surface optical guidance for DIBH, and your billers are probably able to get IGRT reimbursement out of it.
