Whole breast nodal irradiation using supine VMAT and prone 3D planning: A case study

The purpose of this study was to compare the variations in doses to the ipsilateral lung and heart between the supine whole breast and nodal volumetric-modulated arc therapy (VMAT) technique and the prone 3-dimensional conformal radiation therapy (3DCRT) technique. In this study, 3 patients who were simulated in the prone and supine positions were planned using supine VMAT and prone 3DCRT techniques to compare planning target volume (PTV) coverage as well as dose to organs at risk (ORs), including the heart and ipsilateral lung. Although all constraints were met, the ideal treatment technique depended on the patient's anatomy and lumpectomy location. Supine VMAT provided excellent coverage to the target structures but encountered difficulty in limiting dose to the ipsilateral lung and heart. When compared with the supine VMAT technique, the prone 3DCRT limited dose to the ipsilateral lung and heart but provided less dose coverage to the target volumes.