Use Dose Bricks Concept to Implement Nasopharyngeal Carcinoma Treatment Planning
Figure 4
(L’t) Treatment couch was set to 180°, gantry to 172°, and collimator rotation at degree of 199° to create RAO field (yellow meshed area on coronal plane and blue sky color area on patient surface) to compensate the nonoverlap dose deficiency lesion region on left side area (left side on picture). The gantry 172° means the beam direction comes from patient’s left side to right side obliquely when the patient was set in supine and with head toward gantry position. Basically, this portal is a little left anterior oblique incidence to patient. (R’t) The DRR of RAO field. The interface close to “A” (denoted as “split” abutted onto A shape edge on this photo) was opened by jaw to form nondivergence field.
