Beam's-eye-view aided treatment planning for a nasopharyngeal lesion: a case report

We report on the application of CT-based multilevel treatment planning to achieve complete and uniform dose distribution over the entire target while sparing critical structures. Treatment strategy and parameters are chosen on the slice containing the isocenter. Target coverage and organ sparing is achieved on all other slices by independently adjusting the asymmetric field width at each level, stimulating the effects of custom blocks. The optimized field borders are back projected using beam's eye views (BEV) from each treatment angle. The BEV printouts are used to assist the physician in the delineation of field blocking on the simulation films.