Use Dose Bricks Concept to Implement Nasopharyngeal Carcinoma Treatment Planning
Figure 3
(L’t) Left anterior oblique (LAO, yellow color area) field was used to compensate the target dose deficient at left side where it is shown outside the “A” shape at upper right on this figure. The yellow color wash region represents the field aperture of LAO on coronal plane and on patient surface. The central axis plane abutted the interface of “A” shape and LAO, which was created by rotating the collimator to 153°, gantry angle to 180°, and couch rotation to 180°. Forty-five degree wedge with “big head” toward R’t side was added for dose uniform modification. (R’t) This picture shows the Beam’s Eye View (BEV) in Digital Reconstruction Radiograph (DRR) of LAO field. This field was created essentially for compensating the target dose deficiency right side to “A” shape. The interface close to “A” (denoted as “split” abutted onto A shape edge on this figure) was opened by jaw to form nondivergence field.
