[Early and long-term outcomes of treatment in patients with medulloblastoma]. / Sravnitel'nyi analiz otdalennykh i neposredstvennykh rezul'tatov lecheniya patsientov s medulloblastomoi.

OBJECTIVE: To compare the modes of craniospinal irradiation (CSI) and to determine possible factors improving the outcome in patients with medulloblastoma. MATERIAL AND METHODS: The study included 92 patients with medulloblastoma who were treated at the Russian Research Radiology Center between 2008 and 2019. Mean age of patients was 12 years. Classical morphological variant of medulloblastoma prevailed (48.4%). After surgery, 78 patients underwent radiotherapy (CSI + full-volume «boost¼ on the tumor site). Standard risk patients received CSI in a reduced dose after tumor resection. Weekly modification of radiotherapy with vincristine was performed in 73 (79.3%) patients. RESULTS: We significantly (p<0.05) determined the total focal doses for CSI in patients with medulloblastoma. Total resection of posterior cranial fossa tumor improved relapse-free survival by several times. Complete CSI up to total dose of 36/54 Gy ensures the most positive effect compared to irradiation in reduced dose. CONCLUSION: Relapse-free survival significantly depends on total focal dose of CSI. Single focal dose, chemotherapeutic modification of radiotherapy and M-stage had no significant effect on relapse-free survival. Perhaps, this is due to small sample size.

Genetic disorders in primary brain glioblastomas.

Glioblastomas are characterized by a variety of genetic and epigenetic disorders, identification of which allows constantly expanding a list of genes directly involved in carcinogenesis, thus increasing molecular diagnostics, monitoring and predicting disease. Molecular-genetic studies of patients with glioblastomas allowed revealing changes relevant to this disease and determining their prognostic significance. In the future molecular-biological markers along with clinical and therapeutic factors may play a role of separate and independent factors of prognosis in patients with malignant brain lesions.

[Prognostic factors in treatment for low-grade brain supratentorial infiltrative gliomas].

The study showed the results of univariate and multivariate analyses of treatment of patients with low-grade brain supra- tentorial infiltrative gliomas. It was reaffirmed the importance of the most significance of such adverse prognostic factors as histology, tumor size, displacement of midline structures of the brain, age and neurological deficit. When assessing the prognostic significance of severity of the debut of clinical symptoms in this category of neuro-oncological patients as well as radical surgical treatment of the primary tumor there were obtained data confirming the absence of their independent prognostic significance.

[Analysis of predictors influencing the results of the combined treatment for anaplastic astrocytomas (grade III) of the brain].

In our study the analysis of significant predictors affecting the results of treatment of anaplastic astrocytoma brain (grade III) is showed. According to our data to assess the effectiveness of special treatment of these patients is possible with such clearly defined predictors such as age, volume of surgery, initial tumor size and functional status (the Karnofsky index). The study demonstrates that in patients who underwent radiotherapy using single focal dose of 3 Gy overall survivals was comparable with the group of patients who underwent radiation therapy using small dose fractionation. The use of adjuvant chemoradiotherapy in patients with grade III glioma does not increase overall survival rate compared with patients who received only adjuvant radiotherapy.

[Evaluation the effectiveness of radiation therapy high-grade gliomas based on the model of TDF (time-dose fractionation)].

There were showed the possibility of using the model of TDF, through which it was possible to take into account the selection of fractionation of radiation for high-grade gliomas and to judge the effectiveness of treatment. Currently, the basis of adjuvant radiation therapy in patients with primary high-grade gliomas is the use of the traditional mode of fractionation dose of radiation from a single focal dose of 2 Gy up to a total focal dose of 60 Gy to the tumor (bed of the removed residual tumor) in Grade 4 and Grade 3 - 54 Gy. In patients who underwent radiotherapy using a single focal dose of 3 Gy, overall survival rate was higher as compared to the group of patients, which was carried out using radiotherapy small dose fractionation.

[The role of functional status and recursive partition analysis (RPA) classes for the choice of fractionation regimen in patients with high-grade gliomas].

The treatment results of 396 patients with morphologically verified grade 3-4 malignant brain tumors receiving conventional irradiation regimen and irradiation by medium-sized fractions were analyzed to form institutional guidelines.The standard mode of fractionation with a single dose of 2 Gy and total focal dose (TFD) of 60 Gy is appropriate for patients with initial Karnofsky status of 60-100% and Recursive Partition Analysis (RPA) class I-III. TFD increase to 60-62 Gy in grade 4 gliomas and 54-56 Gy in grade 3 gliomas grants a significant improve in overall survival. An increase of a single irradiation fraction to 3 Gy may be used for patients with initially low functional status (Karnofsky 30-50%) and RPA classes IV-VI. In these cases it is advisable to use the TFD of 45 Gy or more (TFD of equivalent regimen with a dose greater than 54 Gy). The mentioned fractionation regimens could be recommended for the use in clinical practice to improve the results of high-grade gliomas treatment.

[The role of age and tumor grade in the choice of fractionation regimen in patients with high-grade gliomas].

There are currently no conventional guidelines for radiotherapy in gliomas. The treatment program is mainly formed in accordance with tumor morphology and the "golden standard" of irradiation is still the traditional mode of fractionation with a single focal dose of 2 Gy and total focal dose (TFD) of 60 Gy. In this report the treatment results of 396 patients with morphologically verified grade 3-4 malignant brain tumors receiving conventional irradiation regimen and irradiation by medium-sized fractions were analyzed to form institutional guidelines. The standard fractionation mode with a single focal dose of 2 Gy is preferable in patients with grade 3 glioma or elderly patients (over 60 years). TFD increase to 60-62 Gy in grade 4 gliomas and 54-56 Gy in grade 3 gliomas grants a significant improve in overall survival. An increase of a single irradiation fraction to 3 Gy may be used for patients younger than 60 years. In these cases it is advisable to use the TFD of 45 Gy or more (TFD of equivalent regimen with a dose greater than 54 Gy). The mentioned fractionation regimens could be recommended for the use in clinical practice to improve the results of high-grade gliomas treatment.

[The role of RPA classification in the treatment of high-grade gliomas].

One of the main gliomas treatment programs development criteria is still the morphology, the RPA classification with risk factors developed for high-grade tumors is rarely taken into consideration. In our study shows a high value on the criterion of overall survival identified in the classification of the six RPA classes. The most important factors in the RPA classification are patient's age and the Karnofsky performance scale value. RPA classification can be useful for new treatment strategies development.