Seroma is an expected consequence and not a complication of MammoSite brachytherapy.

Seroma has long been listed as a complication of MammoSite brachytherapy. Palpable abnormalities are clinically apparent months after treatment and a vast majority of patients demonstrate seroma formation in radiologic studies. We embarked on this study to evaluate the actual sonographic incidence and eventual sonographic resolution, possible contributing factors, cosmesis, pain, and local control associated with seroma formation after MammoSite partial breast irradiation (PBI).