Sequential Sentinel Node Scintigraphy With Planar and SPECT/CT Images Revealed Contralateral Drainage From Ipsilateral Breast Tumor Relapse in a Patient With Bilateral Breast Cancer.

Radio-guided sentinel node (SN) biopsy is routinely performed in patients with early breast cancer. However, repeated SN scintigraphy in ipsilateral breast tumor relapse (IBTR) often shows extra-axillary drainage, including contralateral axilla. A patient diagnosed with bilateral breast cancer, of which one was IBTR, was studied by sequential radio-guided SN mapping, radiocolloid injection to an IBTR breast and scanning, and then radiocolloid injection to the other breast and scanning. This revealed the lymphatic flow from the IBTR breast to the contralateral axilla. Sequential method may help to depict contralateral axillary lymphatic flow from an IBTR breast in patients with bilateral breast cancer.