Objective:To compare the dosimetric characteristics of three fractionated stereotactic radiotherapy techniques,i.e.,tomo-therapy(TOMO),volumetric-modulated arc therapy(VMAT),and CyberKnife(CK),in the treatment of intracranial oligometastases,and to assess their dose distribution,treatment efficiency,and difference in dose delivered to organs at risk(OARs).Methods:A retro-spective analysis was performed for the clinical data of 54 patients with intracranial oligometastases who underwent fractionated stereo-tactic radiotherapy in The First Affiliated Hospital of Army Medical University in 2021-2023.Varian Eclipse 16.1 Physician Worksta-tion was used to perform tumor target volume delineation,and MANTEIA AccContour 3.2 software was used to perform the delineation of OARs,such as brainstem,spinal cord,and optical nerves.The delineated structures and images were transmitted to TOMO,CK,and Eclipse treatment planning systems to design three different radiotherapy treatment plans.Related key parameters were analyzed using the dose-volume histogram to evaluate the dosimetric characteristics of these three radiotherapy techniques,including conformity index(CI)of the target,dose homogeneity index(HI),beam-on time,the number of monitor units(MU),and the exposure dose of OARs.Results:All three treatment plans(TOMO,VMAT,and CK)met the requirements for prescribed dose.TOMO had a slightly better CI than VMAT and CK(1.05 vs.1.09 and 1.17,P<0.001).VMAT had a better HI than CK and TOMO(1.15 vs.1.28 and 1.46,P<0.001).In terms of execution efficiency,VMAT had a significantly shorter beam-on time than TOMO and CK(5 minutes,1 633 MU vs.10 minutes,8 932 MU and 39 minutes,5 191 MU,P<0.001).In terms of the exposure dose of OARs,CK provided the best protection for the lens,with a maximum dose of 15 cGy for the right lens and 17 cGy for the left lens,and TOMO had an advantage in dose control for the right cochlea,with a mean dose of 88 cGy,while VMAT had the best performance in limiting the dose for the spinal cord,with a maximum dose of 31 cGy(P<0.05).Conclusion:This study shows that TOMO,VMAT,and CK all meet the requirements for the prescribed dose and can effectively protect OARs in the treatment of in-tracranial oligometastases.In clinical practice,the most appropriate technique should be selected based on the features of lesions and treatment goals to achieve individualized treatment.