[Experimental study of radiosensitizing effect of analogs of purines and pyrimidine bases in cultured HeLa cells]. / Eksperimental'noe issledovanie radiosensibiliziruiushchego deistviia analogov purinovykh i pirimidinovykh osnovanii na kul'tiviruemykh kletkakh HeLa.

The radio-sensitizing capacity of cultured HeLa cells was investigated by using a number of compounds, which are analogues of purine and pyrimidine bases. Agents (5-fluorouracil, ftorafur, mercaptopyrine) used in chemotherapy for tumors for many years and some compounds (allopurinol and theophylline) that are sterically close to purine and pyrimidine bases and clinically used for various purposes, but have no cytotoxic activity against tumors cells were tested. Fluorouracil was shown to potentiate the action of gamma-radiation when the agent was given used before radiation or used in the concentrations producing no cytotoxic effect. Allopurinol and theophylline do not possess a radio-sensitizing effect. There was a more pronounced radiosensitization in the concurrent use of a double combination of agents and radiation and the greatest cell death rates were observed in the concurrent use of three agents (5-fluorouracil, ftorafur, and methylcytosine) and gamma-radiation.

[Evaluation of conditions of radiation protection of medical personnel during intracavitary neutron therapy of cervical cancer]. / Otsenka uslovii zashchity meditsinskogo personala pri vnutripolostnoi neitronnoi terapii raka sheiki matki.

Combined radiation therapy was provided to 106 cervical cancer patients. Endostats and sources of neutron radiation 252Cf of low activity were administered manually. Working conditions of the personnel were examined, the rate of exposure doses and flows of neutrons at working places were measured, dose exposures of the personnel were evaluated. It has been concluded that occupational conditions for the medical personnel are considered to be relatively safe.

[Role of transvesical ultrasonic scanning in the diagnosis of causes of ureteral stenosis in patients with cervical cancer]. / Rol' transvezikal'nogo ul'trazvukovogo skanirovaniia v diagnostike prichiny stenoza mochetochnikov u bol'nykh rakom sheiki matki.

gamma-Beam therapy of combined radiation therapy are frequently followed by ureteral obstruction, caused by a cervical cancer recurrence or pelvic postradiation fibrosis. The knowledge of a cause is very important for a choice of therapeutic tactics of obstructive uropathy. The purpose was to define the potentialities of transvesical ultrasound scanning (TVUSS) in order to reveal causes of disturbed urodynamics of the urinary tracts after radiation therapy of cervical cancer. TVUSS was performed in 17 women with a confirmed diagnosis. It turned out that a cervical cancer recurrence could be differentiated from postradiation fibrosis by specific ultrasound signs. Another group of 44 patients was investigated using this method to find out causes of disturbed urodynamics of the upper urinary tracts: postradiation pelvic fibrosis was noted in 7 patients, a recurrence of cervical cancer--in 19, a recurrence of cervical cancer with the involvement of the urinary bladder--in 11, and bladder carcinoma--in 3, in 3 other cases the diagnosis was not established as a result of difficulties in interpreting sonograms.

[Beam radiotherapy of malignant tumors using computer-assisted radiotherapy programs]. / Distantsionnaia luchevaia terapiia zlokachestvennykh opukholei s ispol'zovaniem optimizirovannykh na EBM programm oblucheniia.

The authors give a brief description a ROKUS-M + Altai-MT system, its software ASPECT-1, stages of radiotherapy design and implementation of optimized programs. They gave examples of optimum computerized design of irradiation in tumors of the nasopharynx, breast, female genitals, esophagus, lungs, bladder, and rectum. The paper is illustrated with charts of isodoses and distributions corresponding to optimized programs of irradiation.

[Stereotaxic myelotomy in the treatment of pain syndromes in gynecologic cancer patients]. / Stereotaksicheskaia mielotomiia v lechnii bolevykh sindromov u onkoginekologicheskikh bol'nykh.

The paper is devoted to the problems of pain relief in cancer patients. The authors consider indications for operation, methods and results of stereotaxic myelotomy at the supercervical level of the spinal marrow. Six operations were performed with good results. All the patients were women with recurrences of malignant tumors of the female genital system with the noticeable pain syndromes. Methods of specific therapy by the time of operation were exhausted. Myelotomy was performed by way of high-frequency thermal destruction. Anatomicophysiological fundamentals of surgical intervention were discussed. The authors proposed to extend indications for stereotaxic operations to relieve pain in cancer patients.

[Intracavity thermo- and gamma-therapy of uterine cancer]. / Vnutripolostnaia termogamma-terapiia raka matki.

Some methodological problems of the use of intracavitary UHF hyperthermia combined with intracavitary gamma-beam therapy in combined radiation therapy of uterine cancer patients are considered. Indications for the use of this method and radiobiological substantiation of thermoradiotherapy for this group of patients are discussed. The advantages of the proposed method of thermoradiotherapy have been noted on the basis of immediate clinical observations, endoscopic, x-ray and morphometric findings.

[A set of protective technological equipment for intracavitary radiation therapy in oncogynecology]. / Komplekt zashchitno-tekhnologicheskogo oborudovaniia dlia vnutripolostnoi luchevoi terapii v onkoginekologii.

The paper gives the information on a new serially produced kit of protective-technological equipment for intracavitary radiotherapy with the use of manual consecutive introduction of endostats and radiation sources, employed in gynecological cancer.

[Basic trends in the reconstruction of the system of postgraduate training of radiotherapists]. / Osnovnye napravleniia perestroiki sistemy poslediplomnogo obucheniia luchevykh terapevtov.

The authors have summed up the experience accumulated over 20 years at the Chair of Clinical Radiology of the Central Order of Lenin Institute of Advanced Medical Training. Doctors majoring in this field, usually become radiologists at the age over 35 when their creative initiative is on a decrease. Therefore the authors have proposed numerous measures aimed at the improvement of the system of training in radiology and an increase in the number of young specialists.

[Application of the DMF model taking into account volume and area of irradiated tissue to the prognosis of radiation complications]. / Primenenie modeli VDF s uchetom ob"ema i ploshchadi obluchaemykh tkanei dlia prognozirovaniia luchevykh oslozhnenii.

Coefficients Kv and Ks for determination of the influence of a volume and area of irradiated tissues in the assessment of DMF factors were presented. The above coefficients were derived on the basis of calculations and a retrospective analysis of the authors' clinical data on radiation complications in the subcutaneous fatty tissue in teleradiotherapy of malignant tumors. The use of the coefficients will make it possible to predict with greater reliability the probability of radiation complications in designing radiation therapy.

[Radiation therapy of malignant vaginal tumors]. / Luchevaia terapiia zlokachestvennykh opukholei vlagalishcha.

A new method of combined radiation therapy for cancer of the vagina is presented: it includes contact (intracavitary and interstitial) gamma-therapy based on the principle of the manual and automated administration (sing the AGAT-B unit) of endostats and low and high activity radiation sources, and gamma-beam irradiation with irregular shaped fields. The problems of fractionation, a choice of required irradiation volumes as well as summary absorbed dose levels are discussed. An analysis of the clinical efficacy was based on long-term results. The 5-year survival rate in the general group of patients was 41.2%.

[Use of time-dose-fractionation models in planning the radiation treatment of malignant tumors]. / Ispol'zovanie modelei vremia-doza-fraktsionirovanie v planirovanii luchevogo lecheniia zlokachestvennykh opukholei.

New methods of the fractionation of preoperative gamma-beam therapy for breast carcinoma and intracavitary irradiation of cervical cancer patients with 252Cf fast neutron sources have been devised and tested on the basis of the concept of a cumulative radiation effect (CRE) and the system of TDF factors at the Chair of Clinical Radiology, Central Institute for Advanced Medical Training. In the selection of regimens of the fractionation of intracavitary irradiation of cervical cancer with 252Cf fast neutrons using the system of TDF factors one should take into account the RBE of the type of radiation that would be equal to 5 by the criterion of a direct response of a tumor within the range of dose rates between 20-30s Gy/hr. Taking account of a short period of half-life of 252Cf sources fractionation schemes should be corrected from the view-point of the system of TDF factors not less than once in 2-3 mos.

[A system of automated radiation treatment of malignant tumors using optimal irradiation programs]. / Primenenie sistemy avtomatizirovannogo luchevogo lecheniia zlokachestvennykh opukholei s ispol'zovaniem optimal'nykh programm oblucheniia.

The authors sum up their clinical experience in the implementation of optimized irradiation programs for tumors of different sites (the esophagus, lung, female genital organs, ear-nose-throat, rectum and urinary bladder) with the help of the first serial specimen of the system of automated control over irradiation--Altai-MT. The utilization of the system makes it possible to save time and avoid an error in the implementation of complex irradiation programs as well as to lower the exposure of medical personnel to radiation. Tumors with average and low radiosensitivity, biologically highly active and located in the vicinity of organs and tissues with a low limit of tolerance to ionising radiation were used as clinical models. Automated programs of irradiation meet the requirements of the conformity and homogeneity of a dose field within a focus of lesion, gradient conditions on the border with normal tissues, the minimization of radiation exposure in critical organs. The purpose of the automation of gamma-beam therapy of tumors is to unite within the common system automated information topometric units and a gamma-therapeutic computer controlled device.