For the Bellinzona technique patient set-up errors can be determined with the same accuracy from the two oblique radiation beams combined with an AP verification beam as from an AP and a lateral verification beam. Furthermore, both a right and a left oblique beam are used instead of one lateral beam, which gives a better result in case of patient rotations around the length axis.
For the patients treated with the Tetrahedron technique using an AP and lateral verification beam gives the most accurate results for position verification and is therefore recommended.