PubMed Health⌕ Search

Biomedical subjects

V A Kvasov

Publications and source records attributed to V A Kvasov.

18 recordsLinked to original sources
PubMed1991

[Present trends in the development of radiotherapy].

New potentialities of radiotherapy of cancer patients are associated with three scientific directions: investigations in clinical radiology, the use of advantages of radiation advanced technology and guarantees of therapeutic quality. The first direction includes scientifically substantiated regimens of non-classic dose fractionation, various radiomodifiers and their combinations, and individual prognosis of a tumor response to ionizing radiation. This direction based on 3000 cases, holds promise. The second direction is associated with the advantages of modern technology used for diagnosis, topometry and radiotherapy design. The third direction is intended to reduce differences in radiotherapy quality between research institutes and cancer hospitals.

Humans↗
PubMed1991

[Prospects of development of radiotherapy in an oncological clinic].

It is believed that new anticancer potential of radiotherapy lies in further research efforts in the fields of: clinical radiobiology, utilization of the last developments in radiological equipment, overall high quality of radiological service. Research in radiobiology should be aimed at the design of nonstandard dose fractionation, introduction of various modifiers and their combinations, prediction of individual responses of the tumor to ionizing radiation. First-hand clinical data on 3000 cases support the promise of such approach. The advantages of modern equipment could be successfully realized at the stage of confirming the diagnosis and topography++, design of the treatment schedule and in the process of radiotherapy. To warrant the same quality of radiological service rendered in large cancer research centers and provincial hospitals, the latter should be provided with relevant equipment, methodological instructions, participate in current cooperative programs.

Cancer Care Facilities↗
PubMed1991

[A computer system for planning radiation therapy--the ROPLAN].

A computerized system of optimum plans of radiotherapy (computer SM 1420) was developed for the first time in the USSR. The ROPLAN system was adapted to a dosimetric design of irradiation sessions for all radiotherapy units, manufactured in the USSR, and provides for modes of initialization, design, storage and collection of data for all radiotherapeutic methods.

Humans↗
PubMed1986

[Use of radiomodifiers during radiotherapy of patients with malignant tumors].

The utilization of various radiomodifiers (hyperbaric oxygenation, metronidazole and their combination, tourniquet and total body gas hypoxia, unconventional dose fractionation) in radiation therapy of over 2000 cancer patients with tumors of the main sites made it possible to raise therapeutic efficacy using a differentiated approach to a choice of therapeutic tactics with relation to radiobiological specificities. The results obtained made it possible to determine the prospects of a further study of the efficacy of the utilization of HBO and MZ and their combination. Tourniquet hypoxia in view of a narrow range of indications and danger of a tumor protection effect should be abandoned. As to the hypoxic gas breathing mixture containing 10% O2 the absence of such an effect must be proved. Unconventional fractionation is no less promising, and as distinct from radiomodifiers it does not require extra resources or special equipment. The use of large fractions to enhance an antitumor effect, their combination in different succession with small fractions to lessen normal tissue damage as well as superfractionation with relation to tumor oxygen supply, possible reoxygenation, a capacity for repopulation and reparation can ensure at present a true therapeutic advantage.

Combined Modality Therapy↗
PubMed1985

Studies of metronidazole radiosensitizing effect in radiation treatment of patients with oral cavity cancer.

Clinical observations of 26 patients with tongue, oral cavity and oropharyngeal cancer receiving telegammatherapy by dynamic dose fractionation scheme in combination with metronidazole (MZ) and of 38 patients from control group treated by identical schedule without MZ suggest that MZ favors increasing of the radiation damage in tumors of those sites without changing the character or intensifying early radiation reactions. After oral administration of MZ in single doses of 5-6 g/m2 it reaches its maximum in the blood serum within 2-4 h. When the total dose of 30-60 g of MZ was used, a marked toxic effect manifested by gastrointestinal symptoms was observed in 33.3% of patients. MZ has a negative effect on liver functions, however, changes in biochemical tests illustrating it, are reversible and within the norm. Simultaneous studies of biopsy material from 22 patients (11 from each group) in terms of proliferation activity showed that oral cavity tumors contain a significant portion of proliferating cells which notably decrease in the course of radiation therapy. To a greater extent that decrease is marked after irradiation with MZ.

Adult↗
PubMedDate not supplied

[Intraoperative radiation therapy: its technological support, potentials and prospects].

The authors' experience with intraoperative radiotherapy (IORT) in 129 patients with a tumorous process at various sites has demonstrated that in most clinical events, single radiation doses of 10-20 Gy is insufficient to have a persistent local effect and requires additional pre- or postoperative remote irradiation. The use of IORT as a single component of radiation exposure does not lead to significant radiation damages to normal tissues. When IORT is combined with remote irradiation (the latter using doses of 30-60 Gy), 30% of patients develop radiation-induced normal tissue lesions. In the context of enhancing the local effect and, if possible, decreasing the dose of remote irradiation, it is expedient to increase IORT doses, which is in turn fraught with higher incidence and severity of radiation lesions. In this connection, it seems urgent to have a look for the potentialities to expand the radiotherapeutical range. This follows several directions.

Adolescent↗