To perform a challenging test of the AP algorithm, we applied it to some of the most dosimetrically difficult cases encountered in our practice — locoregionally advanced head and neck cancers. Ten consecutive, previously treated cases were selected according to the following criteria: all were treated with 6 MV VMAT beams for 35 fractions, with 70 Gy to the primary target (PTV_70) and simultaneously 56 Gy to the elective bilateral neck nodes (PTV_56); all patients were under the care of the same radiation oncologist and planned by the same dosimetrist. All original plans employed two or three full VMAT arcs and were designed for a Varian linear accelerator with a 120‐leaf Millennium multileaf collimator (Varian Medical Systems, Palo Alto, CA). The physician manually drew the primary gross tumor volume (GTV) and the elective nodes clinical tumor volume (CTV). The GTV was expanded uniformly by 5 mm to create the 70 Gy CTV. This was manually edited to remove bone, fascia, and air. Both CTVs were expanded uniformly by 3 mm to arrive at the corresponding planning target volumes (PTV). The primary (PTV_70) average target volume was 338±262 (1 SD) cm3 with the range from 85 to 1035 cm3. The bilateral elective nodes (PTV_56) had the average volume of 352±94 cm3, with the range from 182 to 490 cm3.