Clinicopathologic Comparison of High-Dose-Rate Endorectal Brachytherapy versus Conventional Chemoradiotherapy in the Neoadjuvant Setting for Resectable Stages II and III Low Rectal Cancer
Figure 1
Representative slices from each of the three radiation plan types taken from a similar level in the pelvis. EBT can be seen to achieve a high dose to the tumor while exposing markedly less normal tissue volume to ionizing radiation as a result of rapid dose fall off from the point source. Top row: in axial (a) and sagittal (b), slices from an EBT plan, the 100% (light blue), 95% (red), 50% (yellow), and 30% (green) isodose lines are shown and the tumor perimeter is contoured (thick light blue line) as well as the bladder perimeter (thick yellow line in axial image, dotted yellow line in sagittal image). Middle row: in axial (c) and sagittal (d) slices from a 3DRT plan, the 100% (red), 95% (bright green), 89% (orange), 67% (gray), 44% (dark green), and 22% (fuchsia) isodose lines are shown, and the planning target volume receiving the full radiation dose around the tumor is indicated (purple shading) as well as the bladder perimeter (yellow). Bottom row: in axial (e) and sagittal (f) slices from an IMRT plan, the 100% (light blue), 97% (red), 95% (green), 90% (fuchsia), 70% (royal blue), 50% (yellow), and 30% (gray) isodose lines are shown, and the planning target volume receiving the full radiation dose around the tumor is indicated (red shading).
