How do you deliver whole breast radiation to a woman with pectus excavatum?

Agree that these can be challenging cases. The technique used depends on the severity of the pectus deformity, need to treat regional nodes (particularly IMNs), and need to treat the whole breast.

@Dr. First Last's advice is sound regarding multiple different plans may be needed and then the optimal selected.

For breast only with mild deformities, generally breath hold or prone breast works if there is minimal breast tissue medially (or physician chooses to undercover medially). For cases where whole breast treatment is not absolutely necessary, we have offered partial breast radiation for suitable candidates (3D or brachytherapy APBI, mini-tangent PBI in the style of UK IMPORT LOW for lateral lesions, or IMRT PBI).

For patients with significa...

I agree with @Dr. First Last's comments; these can be very challenging cases even when internal mammary lymph nodes don't need to be covered. With significant posterior depression of the sternum in pectus excavatum, the resultant anatomy can make it difficult to limit dose to the contralateral breast, heart and lungs while getting sufficient coverage of the affected breast.

We published a case of a patient with pectus excavatum treated with whole breast radiation after lumpectomy for early-stage right breast cancer, comparing treatment plans for 3D, IMRT and VMAT in the prone and supine positions. VMAT provided superior target coverage, while achieving the best sparing of OARs.

The nature and severity of the anatomic abnormality arising i...

These are extremely challenging cases particularly if internal mammary nodes need to be covered.

Prone and breath hold may help but with left sided cases the heart may actually stay relatively close to chest wall. In terms of fields, tangents don’t work well usually but can try electron photon match or imrt.

i have used standard fractionation when treating nodes in these cases.