Dosimetric study of AAA algorithm inintensity modulated radiotherapy for cervical cancer

Objective To investigate the effects of AAA algorithm on cervical cancer IMRT plan and to provide reference for program optimization. Methods A total of 10 patients with cervical cancer undergoing radiotherapy were selected. The Varian Eclipse13.5 planning system was used to keep the number, angle and optimization target parameters of the plan the same. The optimization algorithm was AAA algorithm and PBC algorithm, respectively, and 7-field IMRT plan was designed for each patient. The dosimetric indexes of target area and endangered organs, machine units (MU) and intensity modulation verification pass rate of different algorithm plans were compared. Results In terms of target area, the conformal index and uniformity index of AAA algorithm were superior to PBC algorithm, and the CTV D_max of PBC algorithm was larger (P<0.05). In terms of endangered organs, except for the left femoral head, the dose of AAA algorithm in other endangered organs was higher than that in the PBC algorithm (P<0.05). AAA algorithm presented lower MU than PBC algorithm, with larger average difference was larger (P<0.05). In terms of IMRT verification, there was no significant difference in gamma pass rate under the standard of 3%/3 mm (P>0.05), which were met the treatment standard. Conclusions In the Eclipse planning system, PBC algorithm overestimates the dose in the target area, while underestimates the actual dose deposition of endangered organs. In the treatment, both PBC algorithm and AAA algorithm can be applied for clinical radiotherapy of cervical cancer, but the priority should be given to AAA algorithm with better performance in most aspects to calculate the dose of cervical cancer planning.