Use Dose Bricks Concept to Implement Nasopharyngeal Carcinoma Treatment Planning
Figure 1
(L’t) Picture shows the split field of right superior anterior oblique (RSAO) field in coronal plane. The red color wash area in the center of this picture represents the target. Right and left side parotid glands were represented in pink and brown color, respectively. Both right and left side parotid glands were spared with block. In this field, couch was rotated to 120°, gantry was rotated to 260°, and collimator was rotated at degree of 180°. 60-degree wedge with “thick head” toward gantry side was added for dose uniform modification. (R’t) Picture shows the Beam’s Eye View (BEV) in Digital Reconstruction Radiograph (DRR) of RSAO field. RSAO beam shape (yellow color) covers most of the lesion. There is two-field edge with no divergence, horizontal and vertical field edge along the central axis plane. Both right and left side parotid glands were spared by asymmetry closing jaw.
