What is the maximum V20 on ipsilateral lung that can be safely accepted for 3 or 4-field breast plans?

We routinely treat the IM nodes so my comments reflect this practice:

1. I shoot for a mean ipsilateral lung V20 below 35%. This is achievable in most, though not all, plans.

2. The biggest driver of ipsilateral lung V20 is the amount of lung in the SCV field.

3. While it is tempting to raise the ma...

I believe that the we sometimes forget about the other risk of lung radiation - secondary lung cancers. An older NSABP study and the following (Risk of second primary lung cancer in women after radiotherapy for breast cancer. Grantzau T; Thomsen MS; Vaeth M; Overgaard J. Radiotherapy & Oncology. 111...

We try to keep the V20 below 30 percent for the ipsilateral lung and use different techniques to achieve that goal including matching electrons, an electron and photon combination, or photons alone.