[Stereotactic radiotherapy for cerebral metastases using CyberKnife].Zh Vopr Neirokhir Im N N Burdenko. 2012; 76(1):37-45; discussion 45.ZV
During recent decade development of frameless techniques of fixation enabled introduction of stereotactic radiation therapy in metastatic brain lesions and made possible irradiation of large foci involving or proximal to eloquent and critical brain areas. This paper focuses on comparative analysis of effectiveness of hypofractionation (HRST) and radiosurgery (SRS) using CyberKnife system in cerebral metastases. Since November 2009 till June 2011 54 patients with cerebral metastases were treated using CyberKnife system. Age of patients ranged between 25 and 77 years (mean 54 years). 16 patients received radiosurgical treatment (mean total dose was 22.5-35 Gy, number of fractions varied from 2 to 7, mean volume of irradiation was 22.69 cm3) and 8 patients were treated by HRST with RS of selected foci (mean total dose reached 23 and 30 Gy, mean volume of irradiation was 1.02 cm3 and 11.19 cm3, respectively). Indices of overall regression and stabilization of disease for HRST and SRS groups were 81% and 79%, respectively. With mean follow-up period of 12.3 (1-16.1) months median survival for SRS and HRST reached 6.38 (1-15.8) and 6.2 (0.2-16.1) months and median recurrence-free survival was 3.6 (1-13.6) and 5.5 (2-14.2) months, respectively. Obtained results confirmed biological advantages of fractionated stereotactic radiotherapy of large cerebral tumors in comparison with radiosurgery. Prospective studies with rigid criteria of inclusion are required to determine optimal dose/volume/fractionation interrelations in stereotactic radiation treatment of cerebral metastases.