Though basal cell carcinoma of the lacrimal ducts is a rare disease, the early detection and management for the tumor can give favorable treatment results. At present time common treatment standards for the disease do not exist. However, most authors, previously faced the problem, recommend their colleagues to perform combined treatment with radiation therapy and the surgery, the priority of treatment procedures is not important. But at the same time, radical surgery in in locally advanced tumors often causes surgical problems, high trauma and extensive postoperative defect. When the surgery is used for l treatment of locally advanced tumors, the intervention increases the amount of surgical procedures, and can cause high trauma and extensive post-surgical defect. Because the disease is more often found in younger patients, it is a topical problem to look for the organ-saving treatment technology that determines the vital forecast, the patient’s future life and the quality of his/her life. The use of independent adaptive teletherapy has made it possible to deliver a high dose of ionizing radiation to the tumor and reduce its impact on the surrounding healthy tissue. No complications of treatment or signs of progression were observed during the 15-month follow up period. Thanks to the use of modern equipment for radiation therapy and new medical technologies, it has been possible to achieve the complete tumor regression and maintain a high quality of life for patients, despite the high risk of complications.

Background. Despite the fact that cerebral astrocytoma belongs to low-grade tumors (grade II gliomas), it often leads to disability and death of patients. The localization of the tumor determines the severity of the clinical symptoms of the disease, which significantly affects its prognosis. The choice of the optimal treatment strategy for astrocytoma localized in the brain stem poses challenges and enables the vast majority of patients to be classified as inoperable. Therefore, radiation therapy or chemoradiotherapy are the main treatment modalities for patients with low-grade glioma. The location of the tumor in close proximity to vital centers makes radiation therapy planning difficult., because the delivery of high doses of radiation can cause serious treatment complications.Description of the clinical case. We present a clinical case of a successful treatment of a young, 20-year-old male patient with diffuse astrocytoma of the brain stem. As radical surgery was impossible to be performed, the patient was offered radiation therapy. The morphology, size, and location of the primary tumor posed challenges for selecting an optimal treatment strategy due to a high risk of damage to vital centers, which could lead to disability and even death of the patient. The use of proton therapy made it possible to deliver the maximum allowable dose of radiation to the tumor, limiting radiation exposure to surrounding healthy tissues. The patient received the complete course of proton therapy. After 36 months of follow-up, no complications and signs of disease progression were found.Conclusion. Despite the high risk of treatment complications, the use of proton therapy made it possible to complete the planned course of treatment, achieve tumor stabilization and significantly improve the life quality of the patient.

The aim of this study was to assess the efficacy and safety of two-stage stereotactic radiosurgery using Gamma Knife for treatment of brain metastases. Staging was applied to patients with large metastases, as well as to metastases located near critical structures. In a group of 31 patients, treatment was carried out in 2 stages with 2-4 weeks interval. The mean tumor volume at the time of the first radiosurgery was 10.4 cm3 (0.52 to 19.07; 95% CI: 8.2-12 cm3). The marginal dose at the first and second stages of radiosurgery ranged from 12 to 14.4 Gy, respectively. Median fol-low-up time was 169 days. Overall survival rate, local control, the incidence of complications, as well as changes in functional status were evaluated. Decrease in volume of tumors between irra-diation sessions averaged 36.2%. Overall survival at 3, 6, 12 months was 70, 57.7 and 52%, re-spectively. Local control after 3, 6, 12 months was 92, 87 and 66%, respectively. Radionecrosis was found out in 2 patients. Increase of Carnovsky index in study group after treatment was by an average of 10 points (p=0.007). Thus, two-stage trained stereotactic radiosurgery can be a safe and effective alternative to surgical treatment of brain metastases without worsening the neuro-logical status of patients.

Применение сочетанной лучевой терапии (СЛТ) позволяет повысить эффективность лечения рака предстательной железы (РПЖ) у больных высокого онкологического риска. Остается неясным, имеет ли какое-либо преимущество включение в область облучения регионарных лимфоколлекторов с профилактической целью, поскольку эскалация дозы, как и увеличение объема облучения, сопряжены с высоким риском развития лучевых осложнений, которые, как известно, негативно влияют на качество жизни пациентов. ЦЕЛЬ ИССЛЕДОВАНИЯ Изучение влияния профилактического облучения лимфатических узлов малого таза на непосредственные результаты лечения, а также на качество жизни больных РПЖ высокого онкологического риска. МАТЕРИАЛ И МЕТОДЫ В период с ноября 2019 по январь 2021 г. в МРНЦ им. А.Ф. Цыба 60 больным РПЖ в объеме гормонолучевого лечения выполнена СЛТ. Пациенты были рандомизированы в две группы: с облучением регионарных лимфоколлекторов (n=32) и без их облучения (n=28). На первом этапе лечения проведен курс конформной дистанционной лучевой терапии до суммарной очаговой дозы 46 Гр. На втором этапе однократно выполнен сеанс высокомощностной брахитерапии (192Ir) в разовой очаговой дозе 15 Гр. РЕЗУЛЬТАТЫ Развитие острого лучевого цистита 1-й степени тяжести отмечено у 11 (34,4%) больных 1-й группы и у 12 (42,9%) пациентов 2-й (p=0,83). Во 2-й группе у 1 (3,6%) пациента отмечен острый лучевой цистит 2-й степени тяжести. Острый лучевой ректит 1-й степени тяжести наблюдался у 13 (40,6%) пациентов 1-й группы и у 3 (10,7%) 2-й (p=0,01) группы. ЗАКЛЮЧЕНИЕ Предварительный анализ исследования показал увеличение частоты развития лучевых реакций в группе пациентов с профилактическим облучением регионарных лимфоколлекторов.

Introduction. Currently, one of the effective methods of treatment of intracranial metastases is stereotactic radiosurgery. The main factors limiting its use are the size (volume) of the tumor or the location of the metastasis in critical proximity to radiosensitive brain structures, such as the optic pathways, thalamus, brain stem, due to the high risk of developing local radiation necrosis. To reduce the risk of adverse radiation effects, hypofractionated radiotherapy by linac or staged Gamma Knife radiosurgery is used. However, large brain metastases that cause dislocation of the brain midline structures are traditionally considered an object for surgical excision, the main purpose of which is to eliminate the mass effect caused by the tumor.The objective of the publication: to demonstrate a case of successful application of staged Gamma Knife radiosurgery of large brain metastases accompanied by brain compression and dislocation.Materials and methods. Patient, 38‑year-old, with right-sided hemiplegia (0 score) and large (Ø = 3 cm, V = 12.9 cm3) breast cancer metastasis in the deep site of the left hemisphere, accompanied by severe perifocal edema and braindislocation (midline shift up to 15 mm). The treatment was carried out by Gamma Knife in two stages with an interval of 1.5 months.Results. As a result, not only a complete regression both of the perifocal edema and midline shift were noted, but also a significant decrease of the tumor volume and dramatical improvement in the patient’s neurological status already in the interval between the stages of radiosurgery: restoration of active movements in the right limbs (up to 4 score).Conclusion. This case demonstrates the possibility of effective and safe non-invasive treatment of large brain metastases accompanied by brain compression and dislocation, which makes it possible to achieve regression of the mass effect and improve the neurological quality of life of cancer patients.

ЦЕЛЬ ИССЛЕДОВАНИЯ Сравнительная оценка ранней токсичности лечения, его переносимости, показателей 1-, 2-, 3-летней общей выживаемости и локорегионарного контроля в группе пациентов, получивших радикальный курс химиолучевой терапии в ускоренном или конвенциональном режиме фракционирования. МАТЕРИАЛ И МЕТОДЫ Представлены промежуточные результаты проспективного исследования, в которое включены 115 пациентов с местно-распространенным раком ротоглотки, корня языка и гортаноглотки, получивших радикальный курс конформной химиолучевой терапии в ускоренном (РОД 2,4 Гр за 25—26 фракций) или конвенциональном (РОД 2,0 Гр за 32—33 фракции) режиме фракционирования за период с 2015 по 2020 г. РЕЗУЛЬТАТЫ При сравнительном анализе с группой контроля статистически значимых различий в уровне ранней токсичности лечения выявлено не было (p=0,41). Полный регресс опухоли был достигнут у 57 (86,3%) пациентов в обследуемой группе и у 39 (79,5%) в группе сравнения (p=0,23). Уровень 1-летнего локорегионарного контроля в группе ускоренного фракционирования составил 78,3±5,3%, 2-летнего — 65,9±6,8%, 3-летнего — 54,5±9,2%. Уровень 3-летней общей выживаемости был 80,4±7,4%. Данные показатели статистически не отличались от таковых в группе пациентов, получивших лучевую терапию в конвенциональном режиме (p=0,12—0,82); 53 (80,3%) пациента в обследуемой группе и 37 (75,5%) в группе стандартного фракционирования прошли курс облучения без вынужденного перерыва. Наличие перерыва в лечении у больных обеих групп снижало уровень 2-летнего локорегионарного контроля на 30,2% по сравнению с непрерывным курсом (p=0,02). ЗАКЛЮЧЕНИЕ Химиолучевая терапия в режиме ускоренного фракционирования (РОД 2,4 Гр за 25—26 фракций, СОД 60,0—62,4 Гр) является методикой, сопоставимой по непосредственной эффективности и безопасности с облучением в конвенциональном режиме. В условиях пандемии COVID-19 можно рассматривать данный режим в качестве основного для пациентов с местно-распространенным орофарингеальным раком с целью сохранения прежних объемов оказания профильной медицинской помощи.

Background. It seems advisable to investigate the feasibility of radiation therapy combined with hormone therapy to treat locally advanced prostate cancer. Combination of two ways to deliver ionizing radiation doses enables us to elevate a total tumor dose and to reduce radiation exposure to critical organs. However, the feasibility of combinatorial radiation therapy (CRT) in prostate cancer patients with seminal vesicle invasion remains insufficiently investigated. The number of studies focusing on this problem is still extremely small.Objective of this study is to evaluate the efficacy and toxicity of radiation therapy combined with hormone therapy for prostate cancer with seminal vesicle invasion.Materials and methods. From April 2016 to April 2020, 52 patients with prostate cancer (cT3bN0) received CRT at the clinic of the A.F. Tsyb Medical Radiological Research Center. The median patient follow-up was 29.7 months (from 11.9 to 58.4 months). The mean age of patients was 65.7 years. The initial mean level of PSA was 28.7 ng/ml. Fifty (96.2 %) patients were given radiation therapy together with hormone therapy.Results. The tolerability of CRT appeared satisfactory. Grade I acute radiation-induced reactions of the urinary tract occurred in 13 (25 %) patients; grade II ones - in 2 (3.8 %) patients. Grade I acute radiation-induced reactions of the gastrointestinal tract occurred in 11 (21.5 %) patients; grade II ones - in 1 (1.9 %) patient. Grade I late complications of the urinary tract were noted in 4 (7.7 %) patients; grade II ones - in 2 (3.8 %) patients. Grade I late complications of the gastrointestinal tract were noted in 2 (3.8 %) patients; grade II ones - in 3 (5.8 %) patients.The three-year cancer-specific survival rate was 97 %; the overall survival rate was 83 %. Eight (15.4 %) patients showed prostate cancer progression. Five (9.6 %) patients experienced cancer recurrence in the form of distant bone metastases. In 1 (1.9 %) patient, disease recurrence was associated with involvement of regional lymphatic collectors and distant inguinal lymph node metastases. Local recurrence was noted in 1 (1.9 %) patient. One (1.9 %) patient developed loco-regional recurrence with distant metastasis to bones. The three-year recurrence-free survival rate was 75.6 %.Conclusion. Our study demonstrates that CRT is highly effective in prostate cancer (cT3bN0) treatment while having an acceptable level of complications.

Introduction. Surgery has traditionally remained the main treatment for tumors of the cerebellopontine cistern but is associated with high risks of dysfunction of the cranial nerves. Radiosurgery is usually performed both as an adjuvant treatment and as an independent option.The study objective is to assess the safety of routine use of radiosurgery to preserve facial nerve function in the treatment of tumors of different origins located in the cerebellopontine cistern.Materials and methods. Since March 2018 to March 2020 there were 145 patients with tumors of cerebellopontine cistern (CPC) at the Center for High-Precision Radiology. Vestibilar schwannomas were detected in 116 (80 %) patients, in 37 cases - relapses or remains after surgery. The 22 patients had meningiomas, 6 after open surgery (WHO I). Trigeminal schwannomas - in 3 patients, facial schwannomas - in 2, jugular schwannomas - in 1 and metastasis of prostate cancer - in 1. 31 patients had facial paresis of different degrees after previous surgery. Among non-operated patients, facial paresis before radiosurgery was observed in only 1 patient. Radiosurgery was performed using the Leksell Gamma Knife Perfexion, the mean marginal dose was 12.2 Gy (11-15 Gy), the mean tumor volume was 3.98 cm3 (0.06-17.47 cm3).Results. Follow-up was performed in 85 patients. The mean follow-up was 359.3 days (91-776), the median follow-up was 367 days. Reduction of the tumor volume was detected in 27 patients, stabilization of the process in 15. The average decrease was 23.9 % (95 % CI 16.8-31.0 %). Transient postirradiation increase was observed in 30 patients only in the group of schwannomas and mean tumor volume increase was 53.7 % (95 % CI 38.5-68.9 %). In patients with previous surgery there were not cases of decline or regression facial paresis. Among patients who had not been operated on before radiosurgery, only in 1 case was the development of facial paresis (House-Brackman III) 5 months after irradiation, which amounted to 1.8 %. It should be especially noted that facial nerve function remained unchanged (House-Brackman I) in both patients with facial schwannomas. Also, not a single case of hemifacial spasm was identified.Conclusion. Radiosurgery of CPC tumors with a marginal dose from 12 to 15 Gy has a high degree of safety in relation to the facial nerve. This makes it possible to justify radiosurgery as alternative to traditional neurosurgical interventions.

Introduction. One of the effective and minimally invasive methods prostate cancer treatment is interstitial radiation therapy, the essence of which is the implantation of radioactive microsources into the tumor tissue. Brachytherapy of prostate cancer is performed in more than 20 clinics in the Russian Federation using mainly foreign microsources, but their high cost does not allow increasing the number of operations and opening new brachytherapy departments in the Russian Federation. Based on the model of foreign microsources such as seed No. 6711 (Nicomed Amersham), a technology for the manufacture of microsources with iodine-125 (IPPE SEED) has been developed at the State Research Center of the Russian Federation - IPPE, as well as a pilot production facility with a capacity of up to 50 thousand items per year. Materials and methods. In order to assess the safety of microsources for medical personnel during brachytherapy, local dosimetric control was carried out. As part of a clinical study in 2015, 36 patients with stage T1 – T2 prostate cancer underwent low-power brachytherapy using domestic microsources. Results. The obtained values of absorbed doses do not differ within the limits of measurement errors from the values of doses determined during the operation with foreign microsources under similar conditions. It follows from the data obtained that even the maximum values of the measured local absorbed doses do not pose a radiation hazard when using IPPE SEED microsources for brachytherapy. Among the treated patients, adverse reactions were in the expected manifestations of grade 1 dysuria according to the RTOG / EORTC classification. No gastrointestinal toxicity has been reported. Patient monitoring was continued in order to obtain long-term results of treatment. PSA disease-free survival at 5-year follow-up was 94.4%. Discussion. Clinical trials of Russian medical devices have demonstrated their safety for patients and medical personnel, which was proved by conducting dosimetry control during the procedure itself, as well as during examination of patients after brachytherapy. The effectiveness of Russian microsources I-125 during low-power brachytherapy is demonstrated by a decrease in PSA level from baseline by 87% at a follow-up period of 6 months. The disease-free survival rate for 5 years was 94.4%. The absence of significant radiation reactions both in the early and in the late postoperative period is important. The low cost of microsources produced by JSC «SSC RF – IPPE» relative to foreign analogs makes it possible to increase the number of operations performed annually, and also gives prospects for opening new divisions performing interstitial radiation therapy operations. Conclusions. Russian microsources «IPPE SEED» have successfully passed clinical trials, during which their effectiveness and safety were proved. The study also demonstrated high rates of relapse-free survival and a low level of adverse reactions in treated patients.

Purpose : to analyze toxicity of combined modality radiotherapy in high-risk prostate cancer patients. Material and methods. Short-term outcomes after combined modality radiotherapy were analyzed in 88 prostate cancer patients treated at clinic of the a.F. tsyb medical Radiological Research center between april 2016 and February 2018. the median follow-up time was 13 months (range, 3–23 months). the mean age of the patients was 64.8 years (range, 49–80 years). an initial psawas in the range of 3.5–114 ng/ml (mean 16.7 ng/ml). all patients were considered high-risk according to the d’amico classification. the patients were divided into two groups according to the sequence of combined modality radiotherapy. in group 1, the patients (n=45) received conformal EBRtto a total dose of 44–46 gy, and 2–3 weeks later, they underwent high–dose rate 192 ir- brachytherapy (one single fraction of 15 gy) as a boost to EBRt. in group 2, the patients (n=43) were treated with interstitial brachytherapy followed by EBRtdelivering at total doses of 44–46 gy. Results. All patients eventually completed the combined modality radiotherapy course planned for them. acute, grade 1 genitourinary (gu) toxicities (Rtog/EoRtc) occurred in 29 (32.9 %) patients. acute gastrointestinal (gi) toxicity was grade 1 in 17 (19.3 %) and grade 2 in 2 (2.3 %) patients. late gutoxicity was grade 1 in 6 (6.8 %) and grade 2 in 3 (3.4 %) patients. an urethral stricture developed in 1 (1.1 %) patient. late gitoxicity was grade 1 in 8 (9.1 %) patients and grade 2 in 6 (6.8 %) patients. Conclusion. The preliminary results of this study suggest satisfactory tolerability of combined modality radiotherapy by prostate cancer patients. the level of acute toxicity and complications in critical organs is quite acceptable, which maintains high quality of life for patients and does not exceed the published data.

Brachytherapy is one of the methods of radiotherapy allowing to deliver a highly effective radiation dose to a tumor through a minimally invasive intervention. Depending on the source, brachytherapy can be low- and high-energy. The article describes the main stages of development of prostate cancer brachytherapy both in Russia and abroad. The main methods of brachytherapy used in modern medicine are described. References to recommendations of the leading radiological organizations on low-energy brachytherapy are provided. The main indications and counterindications for brachytherapy for treatment of prostate cancer using low-energy sources are described. Summary data on the effectiveness of the method depending on prostate cancer prognosis are presented. The results of using low-energy brachytherapy at the branches of the National Medical Research Center of Radiology of the Ministry of Health of Russia are described.

Ин виво» дозиметрия при высокомощностной брахитерапии рака предстательной железы с применением 192 Ir: сравнение распределения планируемых и измеренных доз при внутриполостном размещении автономных люминесцентных микродозиметров Степаненко В.Ф., Бирюков В

The study was aimed to the biological effectiveness of the proton scanning beam of the first Russian medical facility. The clonogenic assay of B-16 tumor cells was used as a test system. Cell irradiation was carried out in a suspension condition in a water phantom. Single and three-field exposures were studied. The dose interval was 2-8 Gy. The energy range from 47.5 to 92.0 MeV was used for the Bragg peak formation. The relative biological effectiveness of protons comparing to gamma-rays was 1.2 for single-field and 1.5 for three-field irradiation. The results obtained agree with literature data related to the used cell culture (B-16) and linear energy transfer range (3÷8 keV/µm).

Recently, there has been a growing interest in the use of active beam scanning proton therapy for re-irradiation of CNS tumors. Although this treatment option for recurrent intracranial tumors is considered effective, however, it is rarely used because of severe radiation-induced neurologic complications. We present 3 case reports of using active beam scanning proton therapy for re-irradiation of intracranial tumors. In the first case, the patient with high-grade glioma was treated with proton beam therapy 1.5 years after the previous conventional external beam radiation therapy. Tumor regression lasting 18 months was achieved. In the second case, the patient received repeated proton beam therapy for recurrent esthesioneuroblastoma. After 1.5 years of follow-up, no evidence of recurrence and late toxicity was observed. The third case was unique, since the patient with recurrent hemangiopericitoma of the orbit received 4 courses of radiotherapy to the same area. A significant regression with no evidence of radiation-induced damage was also seen 12 months after the completion of radiation treatment. Conclusion. Recent advances in proton therapy allow for re-irradiation of CNS tumors in effective total doses, while reducing exposure to surrounding normal tissues. The use of PET-CT for contouring the target allows the localization and volume of the metabolically active tumor tissue to be precisely determined.