One of the factors of Mtx toxicity during high-dose chemotherapy is its prooxidant action. For the compensation of arising oxidative stress such antioxidant drugs as ademetionin are used in clinical. The purpose of the study: investigation of the dynamics of antioxidant defense system indicators in children during high-dose chemotherapy. The object of study: 246 patients who received high-dose Mtx chemotherapy, aged 9–15 years.
Methods. Determination of GGT, GR, SOD and OAOS in blood on key hours from the start of Mtx administration – 4, 24, 42, 48; determination of their biokinetics parameters.
Results. For the first 4 courses the regularities are found: GGT activity and SOD have a maximum increase in the 4th hour, further reduced. SOD activity recovers slightly up to 48^th hour. Levels of GR and OAOS are the lowest for the 4^th hour, then increased to a level above the reference one.
Conclusion. Oxidative stress caused by the action of Mtx, can be compensated by coadministration of ademetionine, which has a positive effect on all measured indicators. After 4 courses of high-dose Mtx chemotherapy hepatotoxicity increases despite of treatment with ademetionine the degree of hepatotoxicity is growing, which founds the reflection in the dynamics of SOD and GGT.

Limb salvage surgery with endoprosthetic and plastic soft tissue replacement gives good functional endpoint results. Treatment must include chemotherapy, adequate soft tissue reconstruction and pre- and post operative rehabilitation.

Additive production is perceived as a revolutionary technology. Without this technology, individual adaptation of many medical products and services would not be possible: personalized implants, including exo- and endoprostheses; orthopedic devices, development of bio-production, devices for the introduction and delivery of medicines, precision instruments, anatomical models in vitro. Thus, additive production is already widely used in many areas of medical research and clinical practice, but there remains a huge potential for implementing a variety of technological tasks. The introduction of additive production takes place at a high speed, which makes it necessary to study all the capabilities.

Currently, there is no consensus on the choice of tactics of rehabilitation after the endoprosthetic replacement of large joints in orthopedic oncology. The available data on the features of rehabilitation, depending on the location of the tumor process, the type of endoprosthesis, the method of fixing the legs of the endoprosthesis, were dissected. Conducting comprehensive rehabilitation significantly improve the functional results of surgical treatment and quality of life of patients with tumors of the musculoskeletal system.

Despite significant advances in the diagnosis and treatment of soft tissue sarcomas (STS), problem of local recurrence is relevant like 100 years ago. Missing of universal schemes of tumor monitoring after primary treatment indicates the need of customized detection algorithms of relapses. High risk of recurrence after surgical and even combined treatment requires the use of original complex therapeutic methods and is feasible only at high-volume sarcoma centers.

PEComa is a mesenchymal malignant tumor, which optimal treatment strategy remains undeveloped because of the rarity of occurrence of this tumor. The main treatment is surgery, but investigators continue to search for solutions that could enhance the effectiveness of resection and improve long-term results. This paper presents the case of the relative effectiveness of preoperative hormonal and radiation therapy patient with pelvic PEComa: fixed degree of therapeutic effect in remote tumor was higher than that in the above large meta analysis.

It is known that malignancies lead to the development of tissue hypoxia, or directly related to the acute or chronic hypoxia, which significantly affects the process of tumor growth and metastasis. Since oxygen is necessary for all the major processes involved in wound healing, including resistance to infection, activation of fibroblasts, collagen deposition, angiogenesis and epithelialization, suggested that hyperbaric oxygen therapy (HBOT) promotes the growth of malignant tumors. Thus, for many decades, the focus of researchers was intended to ascertain the validity of this assumption. In the early 2000s Feldmeier, Daruwalla et al. Conducted a literature review about the use of HBOT in oncology. Both authors found that HBO does not promote tumor growth and HBO in patients with malignant tumors is safe. In this article the question of the use of hyperbaric oxygen therapy in treatment of cancer patients, the study of the history of this problem. As well as the results of his own research: the use of HBOT for the treatment of complications after reconstructive operations in oncology.

The total endoprosthesis replacement of the tibia – is extremely rare operation, even in adults. for children of preschool age, as a rule, the amputation was standard of surgical treatment in total or subtotal tumor lesion of the tibia. In department of general oncology of pediatric oncology and hematology institute of N.N. Blokhin russian Cancer research Center we spent an attempt to perform limb salvage surgery with delayed endoprosthesis in a child 5 years old with osteosarcoma of the tibia. The article with our case report describes a unique operation – subtotal resection of the right tibia with replacement spacer of the defect from the bone cement made in our institute. descriptions of these operations in a child of this age, we have not found in the current literature.