Breast Radiation Therapy Using a Breast Cup: Moving the Target, Not the Patient.

Abstract

To compare whole-breast radiation therapy dose distributions with and without the use of breast cups to reposition the breast itself. A fitted plastic breast cup repositions the breast on the anterior chest wall, reducing the lateral fall and ptosis of the breast. Eighteen patients requiring breast cups were identified on an initial simulation computed tomography scan (without breast cup); subsequently, a second scan with the breast cup fitted was performed. An optimal treatment plan was then created on both scans with the differences in radiation dose to underlying organs compared. In vivo measurements were performed to assess any possible bolusing effect on skin dose owing to the breast cup. Breast cups significantly reduce dose to both lung and heart for all left-sided cases. All lung dose metrics decreased for all right-sided cases. Right-sided heart dose metrics did not significantly decrease with the use of breast cups; however, heart mean dose for these cases was all under 100 cGy. A 16% increase in skin surface dose was observed in an anthropomorphic phantom when using a breast cup. Use of the breast cup in breast radiation therapy decreases dose to underlying organs at risk and is cost-effective. It can be easily integrated with deep inspiration breath hold, intensity modulated radiation therapy, and volumetric-modulated arc therapy techniques. With use of the device, a supine patient position can be maintained, meaning nodal regions can be treated mono-isocentrically.