Regional nodal variation.

Yep, we’re still debating nodal target volume delineation for breast cancer. And derivations from a combination of traditional field borders, anatomic considerations, and patterns of failure studies leaves significant room for variation. A useful expert summary considers key differences in the RTOG, ESTRO, and RADCOMP atlases and makes recommendations about which is most useful in different clinical situations. In very general terms, the ESTRO volumes were designed for early-stage breast cancer. They typically offer better coverage of the low axilla with less extensive supraclavicular coverage. As a result, ESTRO volumes are favored when treating low volume nodal disease (i.e. sentinel node positive). The RTOG and RADCOMP volumes have more generous coverage of the upper axilla and supraclavicular nodes. In particular, the RADCOMP volumes have more extensive IMN coverage and also include the posterior triangle of the neck. As a result, these volumes are preferred when treating higher volume nodal disease (i.e. N2 or N3). TBL: This review from the TransAtlantic Radiation Oncology Network is a great resource (including tables and pictures) for understanding differences in breast cancer target volumes. | Loganadane, Int J Radiat Oncol Biol Phys 2020