e17514 Background: Malignant pelvic tumors account for more than 25% of cancer incidence in Russia. Radiation therapy is the most common treatment for such patients; however, 10-15% of patients develop radiation-induced complications of the pelvic organs, and more effective treatments are required to manage these complications. Methods: The study included 30 patients with cervical cancer T3NхM0 after combination treatment. 7-10 months after combined radiation treatment (total radiation dose to the primary focus 80 Gy), patients developed erosive ulcerative radiation rectitis (RTOG grade 1 and 2). Patients were divided into 2 groups: main group (n = 15) – conservative treatment combined with LILEDR. Each course included 10 LILEDR sessions, the red spectrum λ = 640 nm on the cubital vein projection (exposure time 5 minutes, dose 6.86 J/cm2) and locally on the ulcerated zones (exposure time 3 minutes, dose 3.96 J/cm2). Patients received 2 LILEDR courses with a 1-month interval. The control group received only conservative therapy. Results: Main clinical manifestations of rectitis (tenesmus, bloody mucous discharge) disappeared in the main group already on the 3-4th day of the first course, epithelialization of ulcerative defects occurred in a shorter period of 7-10 days. Soft superficial scars not causing rectal stenosis formed at the site of the ulcer by the end of LILEDR courses. The control group showed long periods of the ulcer epithelialization up to 30 days, late remission and a lingering recurrent character of the disease. Conclusions: LILEDR in combination with the main conservative therapy allows rapid managing with the clinical symptoms of radiation rectitis and regression of disorders developed after the complex treatment, which improves the quality of life of patients and shortens the rehabilitation period.

Цель исследования. Анализ полученных в течение четырех лет наблюдений результатов проведенной стереотаксической радиохирургии (SRS) и стереотаксической радиотерапии в режиме гипофракционирования (SRBT) экстра-и интракраниальных опухолей в ФГБУ «НМИЦ онкологии» МЗ РФ. Пациенты и методы. В исследование включено 277 пациентов, разделенные на 3 группы. В первой группе 184 пациента (66,4%) с примененной SRS, во второй группе 54 пациента (19,5%) с примененной SRT, в третьей группе 39 больных (14,1%) с проведенной SRBT экстракраниальных опухолей. Разработка планов лучевой терапии проводилась на системах планирования iPlan и Elements, BrainLab. Лучевая терапия проводилась на линейном ускорителе Novalis Tx, Varian. Оценка проводилась с использованием программного обеспечения iPlan и Elements, BrainLab, путем сравнения объемов опухолей по данным МРТ исследования головного мозга и СРКТ для экстракраниальной патологии в момент лечения и в течение четырех лет наблюдения. Использовались стереотаксические радиохирургические и гипофракционные методики лучевой терапии. При радиохирургическом лечении лучевая терапия проводилась с однократным высокоточным подведением терапевтической дозы к мишени с целью биологического эффекта в облучаемом объеме при минимальном воздействии на окружающие ткани. Разовые очаговые дозы (РОД) подбирались в зависимости от гистологии, а предписание дозы проводилось согласно принятым критериям The International Commission on Radiation Units and Measurements (ICRU) (2010) Report 83. Гипофракционированная стереотаксическая лучевая терапия проводилась с использованием 2-5 Фракций (Фр) со средним диапазоном РОД 3-10 Гр. Результаты. В течение всего периода наблюдений в группе пациентов после SRS в 69,8% случаев отмечена положительная динамика, в 19,6% отмечена стабилизация процесса, в 9,8%-отрицательная динамика. В группе SRT у 59,3% больных наблюдается положительная динамика, в 21,4%-отрицательная динамика и в 9,3%-стабилизация процесса. В группе SRBT экстракраниальных опухолей в 38,5%-положительная динамика, в 58,9% отмечена стабилизация процесса, в 6,7%-отрицательная динамика. Заключение. Анализ полученных данных говорит о высокой эффективности методик SRS и SRBT, которые позволяют добиться локального контроля как над злокачественными, так и доброкачественными новообразованиями.

At present, there are some scattered evidence data pertaining to the use of an adaptive technique of radiotherapy in treatment of malignant glial tumors of the brain. Our evidence data obtained in MRI in the course of treatment show that the initial treatment plan may become irrelevant due to some changes observed in the tumor configuration. In its turn, it bears witness to the topicality of developing and introducing adaptive methods and techniques in the brain tumor treatment, which are capable to increase efficacy and tolerability in patients with primary malignant tumors of the brain. Aim. Our aim has been to develop an adaptive stereotactic method of radiotherapy in treatment of primary malignant brain tumors, which shall be capable to increase efficacy and tolerability of radiation therapy as well as reduce radiation dose to normal structures in the brain. Materials and methods. Our method has been elaborated with recruiting a group of 10 patients diagnosed with primary glioblastoma G IV, which have received specialized treatment at the National Medical Research Centre for Oncology at the Ministry of Health, the Russian Federation, in the period 2021-2022. The average age of the above patients is 43,4 years. All patients have undergone microsurgery covering the total resection of the tumor (3 patients) and subtotal removal of the malignant tumor (7 patients). The average time interval between the surgery and radiotherapy is 32,5 days. Before treatment, an intravenous contrast enhancement MRI of the brain with an axial pitch of 1 mm has been conducted employing the contrast T1, contrast-free T1 and T2 FLAIR modes. Planning of radiotherapy for this sort of patients has been carried out employing BrainLab Elements и Varian Medical Systems Eclipse. The CTV was defined as a 2,0 cm margin around GTV with an anatomical correction. The CTV-to-PTV margin was 0,1 cm. Doses have been administered as follows: a single dose of 2 Gy up to a total dose of 60 Gy in 30 fractions. The brain has been MRI-scanned in all patients with the use of intravenously introduced contrast agents with an axial pitch of 1 mm employing enhanced contrast/contrast-free T1 sequences and T2 FLAIR to redefine the radiotherapy targets (GTV, CTV, PTV). At fraction 30 we have completed MRI in order to estimate the treatment outcome. In the average, the radiotherapy course has taken 42-45 days, holidays included. For the purpose of the radiation therapy, used have been the Novalis Tx Varian Tx linear accelerator of kinetic energy of the beam of 6 MeV. Results We have developed our own adaptive stereotactic method of radiotherapy to treat the primary malignant glial tumors in the brain, which is capable of tracing the configuration of the post-surgery cavity, the residual tumor and the brain structures in the course of radiotherapy and adapting the therapy plan thereto that makes possible to reduce tissue volumes exposed to radiation due to a decrease in the tumoral and peritumoral volumes of the tumor and post-operative cavity. Conclusion. Our analysis has shown that in the course of radiotherapy some anatomical changes in the tumor configuration are found. An adaptive approach applied to radiation therapy allows monitoring the above changing volumes and correcting the treatment plan.

e17515 Background: The purpose of the study was to evaluate advantages of combination ozone therapy as an effective factor of radiomodification and radioprotection in the treatment of patients with cervical cancer. Methods: The study included 20 patients with stage IIIb cervical cancer T3бNхM0, the mean age 52 years. Controls (n = 10) received standard chemoradiation therapy; the main group (n = 10) received combination ozone therapy in addition to chemoradiation therapy. Systemic ozone therapy involved intravenous administration of 250 ml ozonized solution of 0.9% sodium chloride, 15 sessions during external beam radiotherapy. Local ozone therapy involved 15-minute instillations into the vagina during brachytherapy. All patients received standard chemoradiation therapy, total irradiation dose to the primary focus 80 Gy, plus weekly cisplatin 40 mg/m2. Results: In the main group, pain and discomfort in the lower abdomen were managed in 20% patients by the 5th session of ozone therapy; 30% - on the 10th day; in 50% - on the 14th day. In the control group, such symptoms in 40% of patients were reduced after 20 days. The main group showed a more rapid regression of tumor infiltration, disappearance of purulent discharge, relief of intoxication syndrome. Manifestations of gastrointestinal toxicity were observed in 10% of the main group and in 100% controls; leukopenia developed in 7 patients in the control group and was not registered in the main group. MRI showed complete clinical regression in 90% in the main group and in 65% in the control group. The treatment was completed within 7 weeks in the main group and 8.5 weeks in the control group. Conclusions: Combination ozone therapy causes a more pronounced antitumor effect, and its radioprotective effects significantly reduce the severity of chemotherapy-induced disorders. It does not aggravate concomitant pathology and shortens the treatment period.

Objective To study the copy number of genes-components of signaling cascades involved in DNA repair, cell cycle regulation and apoptosis under the influence of high doses of ionizing radiation.Material and Мethods The study was carried out on a culture of H1299 non-small cell lung cancer cells. Cell lines were cultured in a Binder incubator (Germany) for 24 h (at 37 °C, 5% CO2 ), and then the groups were divided into therapeutic and control. The first one was irradiated with a NovalisTx, Varian linear accelerator at doses from 18 to 24 Gy, the second was not exposed to radiation. During the study, we monitored cell viability and evaluated apoptotic activity, then each sample was amplified in two iterations. During the study, cell viability was monitored, apoptotic activity was assessed, and then each sample was amplified in two replicates. The relative copy number of genetic loci was determined by Real-Time qPCR (RT-qPCR).Results When comparing the relative copy number in the genetic loci of the H1299 non-small cell lung cancer cell culture after exposure to a high dose of ionizing radiation, a statistically significant decrease in the relative copy number of the CASP3 and RBBP8 genes was found, which may indicate a decrease in the potential of caspase-mediated tumor repopulation and an increase in the radiosensitivity of tumor cells.Conclusion Exposure to high doses of ionizing radiation leads to a detrimental effect on tumor cells and allows to overcome one of the mechanisms of radioresistance – tumor cell repopulation.