Images of (a) INTRABEAM® source (Carl Zeiss Surgical, Oberkochen, Germany) on gantry arm with spherical applicator attached, and internal schematic (image provided by Carl Zeiss Surgical); (b) Xoft® Axxent® system (iCAD Inc., Nashua, NH) external trolley, and close up of source (image provided by Xoft/iCad); (c) Papillon (Ariane Medical Systems Ltd, Derby, UK) source on gantry arm (image provided by Ariane Medical Systems), (d) Esteya® EB system (Elekta AB-Nucletron, Stockholm, Sweden) (image provided by Elekta), (e) Photoelectric therapy system (Xstrahl Ltd, Camberley, UK) (image provided by Xstrahl), (f) SRT-100™ (Sensus Healthcare, Boca Raton, FL) unit (image provided by Sensus Healthcare).