*Treatment of Head and Neck Cancers Using Radiotherapy DOI: http://dx.doi.org/10.5772/intechopen.103678*

arrangements in static beam IMRT. The mechanism of selecting the beams is by elimination of beams from up to 400 pre-assigned beams orientations. Then, the calculation of fluence optimization iterations can help to eliminate the beams that cause the least contribution to the pre-set objective functions until the number of desired beams is reached. Planners must customize the resulting number of beams, coplanar or non-coplanar arrangement, and the number of initial beams. Also, objective functions for each target volume and OARs must be set beforehand for the purpose of fluence optimization in the beam elimination process. The user interface of BAO is shown in **Figure 5**.
