부산대학교 도서관

Purpose: Pilocytic astrocytomas (PA) are the most common gliomas (WHO I) in children. According to lots of trials in different countries Stereotactic Radiation Therapy (SRT) and Radiosurgery (SRS) provide tumor growth control if surgical removal is not possible or in case of recurrence. In this paper, we have summarized our own experience with radiation treatment of PA, which composes the largest series available. Materials and methods: The study included 410 consecutive patients who received radiation treatment at the N. N. Burdenko National Medical Research Center of Neurosurgery between April 2005 and January 2018. There were 225 female and 185 male patients. The study group consisted of 110 adults and 300 children (including those under the age of 18). The median age was 10.8 years (Q1-Q3: 5.4-19.3 years). Histopathological verification was performed in 307 cases (74.8%). In 103 patients (25.2%) the diagnosis was established according to clinical and neuroimaging data (MRI, CT-perfusion and PET). The indication for the radiation treatment was a residual tumor after surgery (204 pts, 49.7%) or recurrence after previous removal or chemotherapy (206 pts, 50.3%). Standard fractionation was used most frequently (292 cases, 71.2%). Hypofractionation and radiosurgery were used in 61 (14.9%) and 57 (13.9%) cases, respectively. Results: The median follow-up period was 68 months (range - 3-300 months) from the diagnosis establishment. 391 patients (95.4%) were available for the follow-up. The median follow-up period after irradiation was 45 months (range - 3-162 months). The 5-year PFS was 97,5% and 5-year OS was 99%. Undesirable events occurred in 77 (19.7%) patients: pseudoprogression – in 67 patients (89.5%), tumor progression – in 8 patient (4 local and 4 distant repalses), brain stem necrosis and intratumoral hemorrhage – in 1 case each. In cases where radiotherapy was delayed until disease progression, the tumor volume was larger and the patients’ state was worse than when irradiation was performed immediately if there was a residual after surgery. Conclusion: Stereotactic irradiation is the effective method of treatment for PA in patients with residual tumors, patients with PA relapse and patients with progressive disease. The treatment should be indicated as early as possible after partial resection. The most common adverse event after irradiation is pseudoprogression. [ABSTRACT FROM AUTHOR]