Objective — to draw up an algorithm for postoperative radiation therapy with a prescribed single dose of 3 Gy for adult patients with verified high-grade glioma. Subject and methods. In 2013 to July 2017, the P.A. Herzen Moscow Oncology Research Institute treated 65 patients with verified high-grade gliomas (Grade 3 and Grade 4 gliomas in 11 (16.9%) and 54 (83.1%) patients, respectively). The total effective dose for each patient undergoing postoperative radiotherapy (n = 50) was calculated from the individual value of the mean single dose using the LQED2 (linear quadratic equivalent dose as 2 Gy) formula (H. Withers, 1992) with α/β =8.5 Gy. Fifteen patients with glioblastoma received only medical treatment; radiation therapy could not be performed. The investigators included separately and analyzed overall survival rates in 30 patients with low performance status (Karnofsky Performance Status, 50% after surgery), who underwent radiation therapy in other radiology hospitals immediately after microsurgery. Results. The developed radiation therapy algorithm consists of several steps. Step 1. Time periods after microsurgery. If radiotherapy can be started not earlier than 6 weeks after surgery, 1—2 temozolomide (TMZ) treatment cycles, followed by delayed radiation therapy, are recommended to reduce the risk of continued tumor growth. It should be noted that at their late visit to a primary radiologist, 39.4% of patients report signs of continued growth at a median of 5.21 weeks (4.0—6.5). Step 2. Performance status before radiation therapy. It is advisable to prescribe neoadjuvant treatment with TMZ immediately after microsurgery in a patient with a low performance status associated with a low tumor resection level, concomitant edema, and mass effect. If chemotherapy improves subsequently the performance status, the delayed radiation stage is quite effective. Step 3. The choice of parameters for radiation therapy. The LQED2 model was used only as a tool to calculate cumulative isoeffective doses for each patient with α/β=8.5. More stringent approaches to radiation therapy are required for better local control in patients older than 55 years (the aggressive course of gliomas). In a group with a cumulative effective dose of more than 60 Gy, the first progression occurs later than in that with smaller doses (<60 Gy), median relapse-free survival is 10.8 months versus 2.1 months (p=0.000). The dose thresholds may be lower in younger patients. In a group with a dose of 58 Gy or more, the first recurrence occurs at a median of 12.7 months versus 6.9 months in that with a cumulative effective dose of lower than 58 Gy (p=0.013). To achieve the cumulative effective dose of 60 Gy or more (α/β=8.5), the mean dose summed up for 19 fractions should not be lower than 2.91 Gy; to attain the cumulative effective dose of 58 Gy or more, the mean dose for 18 fractions should be 2.95 Gy or higher. Step 4. Relative contraindications to dose escalation. Despite the existing complications, the described procedure of radiation therapy is safe. The radiation therapy cycle with 19 fractions and more should not be used in PTV >200 cm3 and in patients older than 70 years; this should be used with caution in 65—70-year persons and in patients with periventricular localization, significant primary dislocation and transition to the other hemisphere. Conclusion. Calculation of the LQED2 cumulative isoeffective dose from individual mean dose allowed formation of favorable and unfavorable prognosis groups. Together with a number of other risk factors, the algorithm was drawn up for radiation therapy with a prescribed dose of 3 Gy, which describes criteria for the feasibility of dose escalation using hypofraction programs.