Résumé
Objective The aim of this study was to evaluate the role of multicriteria optimization (MCO) in planning of intensity-modulated radiotherapy (IMRT).Methods Twenty IMRT patients (ten with prostate and ten with lung cancers) were randomly selected.For these patients,the treatment plans were designed with direct machine parameter optimization (DMPO).Based on these plans,new plans were designed with MCO,while keeping the setting conditions unchanged.Comparison was made between the two plans including the dose distribution,the dose volume histogram,the time of optimization and number of monitor unit (MU),but were play by pairing-t test.Results The plan designed in both optimizations satisfied all clinical requirements.For the same or better target coverage,rectum,bladder and small bowel were better with MCO compared with DMPO,MCO reduced 58％ of the time for optimization by average while MU increased 32％ by average for prostate cancer.For lung cancer,the whole lung,heart and spinal cord were better with MCO compared with DMPO,MCO reduced 59％ of the time for optimization by average while MU increased 11％ by average.Conclusions In comparison with DMPO,MCO reduces the dose of organs at risk,shorten the time of optimization.