ИСТИНА

Objective: To evaluate the role of gamma knife stereotactic radiosurgery (GKRS) in patients with recurrent or residual intracranial ependymomas after resection and fractionated radiation therapy (RT). Methods: We retrospectively reviewed patients with anaplastic ependymomas who underwent GKRS between 2006-2016 after progression from initial multimodal treatment. From April 2005 till September 2017 at "Center "Gamma Knife" Moscow" affiliated with Burdenko Neurosurgery Institute 78 patients with recurrent and metastases of anaplastic ependymoma was treated at 122 single fraction RS procedures using Leksell Gamma Knife Model C (before May 2009) or Perfexion (thereafter). Group includes 45 male and 33 female with average age on the moment of first GKRS 12 years (from 2 to 59); most patients has age less than 20 (65 patients; 87%). All patients had previous surgical resection of their ependymomas followed by radiotherapy, and underwent chemotherapy. The median time from initial treatment to GKRS was 17.5 months. 23 patients had 2 and more GKRS (maximum 8!). Some of patients additionally treated in hypofractionation regimes using other devices. In most cases GKRS was done with PD from 18 to 24 Gy, except cases where GKRS was used as boost to craniospinal treatment (12 Gy, 1 case), large local irradiation volume or critical structures like brainstem or optic nerves or chiasm in touch (15 - 16 Gy). Average PD=19 Gy (12 - 24 Gy), average PI=58% (39 - 92%).. Average tumor volume - 1.7 cm3 (2 mm3 - 33 cm3). Results: Progression-free survival after the initial SRS was 68.4%, at 1 year respectively. The distant tumor (metastases) relapse rate despite RT and GKRS was 20.6% at 6 month and 45.0% at 12 month respectively. Overall survival after GKRS was 89.5% at 1 year, respectively. Adverse radiation effects developed in 10 patients (11.3%). Conclusions: GK Radiosurgery may be effective for local control in the treatment of recurrent and metastases of such resistant tumor as anaplastric ependymomas. The radiosurgical treatment in adult or pediatric patients with local or distant relapses of anaplastic ependymomas is a reasonable option and increases overall survival of these patients.