Objective To compare the dosimetric and organ at risk dose differences of volumetric modulated arc therapy( VMAT),seven-fixed field intensity-modulated radiation therapy( 7-IMRT) and nine-fixed field intensity-modulated radiation therapy( 9-IMRT) for cervix cancer treated with the definitive whole pelvic radiotherapy. Methods CT images of twelve patients treated with three plans of VMAT,7-IMRT and 9-IMRT techniques were compared in terms of parameters of target,organ at risk( OAR),conformity index( HI) and ...