Lung Treatment after Left Breast Irridation

[MedPhys2MD]

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We have a patient that we treated her left breast about a year ago and how she has left lung and mediastinum cancer we need to treat. Any suggestions on what to be most cautious of when planning her lung treatment?

Don’t want to give much dose to the left breast that was already treated but also don’t want to give much dose to the right lung...

 

[medgator]

Wouldn't worry too much about the breast tissue, personally. Maybe a little more cautious based on the time interval, but there are reports of patients getting repeat whole breast radiation years later for isolated recurrences so I am not really sure what your dose-limiting toxicity in the breast would be.

 

[evilbooyaa]

Not entirely sure what the issue is here. Unless this is directly in the SCV field or immediately posterior to the breast (meaning it got clipped through) I wouldn't worry about it. Basic entry/exit dose through the left breast is not an issue whatsoever. Follow normal lung constraints and beam on. If it makes you feel better, do an avoidance.

 

[Mandelin Rain]

I wouldn't worry at all, unless (as said) the plexus is an issue. If it is directly adherent to the chest wall in the previous tangents, I'd probably counsel her on a low risk of soft tissue injury of the chest wall, but breast tissue/skin? Nah.

 

[Palex80]

You are concerned mostly about late effects when it comes to the breast in this case, I presume. I cannot imagine that dose to the skin would be an issue.
Yet this is a patient, where you need to treat the mediastinum too, thus she's at least stage IIIA. There is a great chance that any late effects to the breast are irrelevant, since the NSCLC is going to determine the patients fate. And with a stage IIIA chances are less than 50%, that's she's going to make it down the road.

Spare the lungs as much as possible and accept more or less any dose to the breast, unless you have problems with the plexus.

 

[seper]

I've had 3 or 4 patients just like that, and the biggest risk here is radiation pneumonitis after the second course of irradiation. Be very tight with margins and lung DVH.

 

[evilbooyaa]

I'll agree with above that do a plan sum with the breast treatment and use that as your V20 estimate to minimize the V20. Based off 0617, I don't think controlling V5 is of strong importance in lung cancer treatment (and not worth sacrificing V20 for). Similar to 0617, minimize heart dose as well.