Fig. 7.

Color-wash isodose distribution in axial CT plane of a phantom prostate (red) with seeds implantation without spacer implantation (A) and with spacer (yellow) implantation (B), with gross tumor volume (GTV; hypo-dense structure – contouring dark red) and clinical target volume (CTV; dark blue). The prescribed dose to CTV was 210 Gy (green isodose). Isodose lines colors are yellow, light-blue, marine-blue, purple, and pink, with the corresponding 280 Gy (140%), 160 Gy (80%), 120 Gy (60%) 80 Gy (40%), and 40 Gy (20%), respectively. The rectum with spacer is solely covered by a small isodoses of 40 Gy