This is a great discussion. I didn't know I'd be having it but I would have thought the PBI question was settled (way more so than which fraction regimen to use... 5 vs 15 vs 16 vs plus/minus boosts). It's good to push at the edges sometimes by contrapositive reasoning. That is, if partial breast is
not indicated in a given case, then whole breast RT is
not a misadmin. But if the opposite is true... that is to say partial breast
is indicated... then whole breast
would be a misadmin. One could use this form of logic speciously in a great many ways, but in this instance based on that tweet, it is hard to refute that when PBI is indicated whole breast would be a misadmin because the wrong site is being treated.
But they do benefit. When PBI is indicated, there is no benefit for any measure for whole breast.
The word "typically" is doing the work in this sentence. Partial breast can be just as simple as a whole breast arrangement and if so would always have equal or less heart dose.
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In IMPORT LOW the ~5y LC was twice as a better with PBI. Depending on the lens, there is even a trend w/ better LC with PBI. I'm not saying that there's better LC w/ PBI... but I can't say that whole breast has even a "marginal positive impact."
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"That's it"... not really. Also toxicities.
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Well now that you mention it I do. You probably do too. NCCN breast guidelines don't endorse IGRT except if DIBH is being used. They don't want us to "alwaysbeIMRTing" unless 30 Gy/5 fx is being used where 26 Gy/5 fx is probably the ideal 5 fraction PBI dose and whole breast IMRT vs 3D is the most studied IMRT question in our field and made IMRT proven to be best; but, again, IMRT is barely mentioned in the guidelines. Now throw in outdated rec's regarding axillary staging...
... and endorsing ENI for say a cT1N1/ypN0 patient...
the NCCN guidelines are very problematic. They do "endorse" PBI. Does that mean if a treatment is endorsed and you do the thing that's not quote-unquote endorsed it's a misadmin? IDK.
But ASTRO guidelines do say PBI is preferred over whole breast.
When PBI is indicated (e.g. a 70yo T1N0 ER+ patient), shouldn't PBI "meant" to be given? I suppose that's the core question.
Absolutely
🙂 Can you imagine being in a tumor board 15y ago and someone doing dog leg fields on a stage one seminoma? Much shaming.
Or partial breast external beam RT on a 70yo lady with stage one ER+ breast in the same tumor board 15y ago?!
Extreme volume shaming.