[The probable causes of thyroid diseases in the victims of the Chernobyl accident]. / Veroiatnye prichiny zabolevanii shchitovidnoi zhelezy u postradavshikh v rezul'tate Chernobyl'skoi avarii.

Ideas about the thyroid gland diseases development in people suffering from the Chernobyl accident explaining the absence of straight dose dependence of pathologies raise from the irradiation were elaborated. It is supposed that the probable reason for a number of these pathologies can be the inadequate and inopportune preventive iodine administration. It is known that significant amount of iodine being incorporated in children or persons with compromised thyroid gland could lead to a number of pathological changes, primarily to autoimmune thyroiditis which is a reason of other consequent pathologies of this organ. The principal mechanism of the process can be presented as following: iodine transformation (oxidation) in the thyroid gland accompanies with the generation of considerable quantities of various radicals imitating the radiation damage. This hypothesis allows to consider the children suffered from the Chernobyl accident with autoimmune thyroiditis as belonging to the group of risk as the literary data testify that the presence of autoimmune thyroiditis rises 75 time the risk of malignant lympho-proliferated diseases appearance. A simple immunological method of autoimmune thyroiditis diagnostics was developed which informativity is comparable with the method of ultrasound diagnostics. Serial production (the antibodies to microsomal fraction of thyroid gland) was organized. This method can be used in screening investigations.

[Treatment of disseminated breast cancer with combined irradiation of the hypophysis by protons and zone gamma irradiation of the skeleton]. / Lechenie disseminirovannogo raka molochnoi zhelezy sochetaniem oblucheniia gipofiza protonami i zonnogo gamma-oblucheniia skeleta.

Survival was assessed in three groups of disseminated breast cancer with multiple bony metastases. Group I (194 patients) was given a combination of proton irradiation of the pituitary and sequential zone gamma-ray teletherapy of the skeleton, group II (98) received the first component and group III (162 cases)--the latter component of the modality only. Cumulative survival curves for groups I and II were well approximated by exponential function of the follow-up period; mean survival was 36.4 and 11.4 months, respectively. The difference was statistically significant. Within a period of about 12 months, survival curves for groups I and III were nearly identical. However, with the increasing number of bony metastases, the group III curve slope tended to match that of group II. Corresponding mean survival for that segment of the curve was 13 months. Mean survival for historic control was 12.1 months. Thus, pronounced and lasting increase in survival was not observed unless the procedures were used together.

[Proton irradiation of the hypophysis and gamma therapy of multiple bone metastases in the complex treatment of breast cancer]. / Protonnoe obluchenie gipofiza i gamma-terapiia mnozhestvennykh metastazov v kosti v kompleksnom lechenii raka molochnoi zhelezy.

The paper is concerned with the results of multimodality therapy of 190 patients with generalized breast cancer with the prevalence of bone metastasis. Irradiation of the hypophysis by narrow proton beams at a dose of 100-210 Gy and gamma-beam therapy of all affected skeletal zones at a dose of 20-24 Gy in 5-6 fractions were employed in multimodality therapy. The total 50% survival was 42 mos.

[Concept of isoeffective doses in radiotherapy]. / Kontseptsiia izoéffektivnykh doz v luchevoi terapii.

The authors proposed the use of absorbed doses in standard regimens of irradiation to illustrate end-effects of unconventional variations of radiation therapy. They proposed that such doses should be defined as "biological isoeffective doses under standard conditions of radiation therapy" or, in short, "standard isoeffective doses". Three standard regimens of irradiation were described: separately for beta-beam, for continuous interstitial and fractional intracavitary radiotherapy. It was proposed that a standard isoeffective dose value should be expressed in "isogray" abbreviated as (i) Gy.

[Effect of x-irradiation on the kinetics of 5-iodo-2'-deoxyuridine in a tumor]. / Vliianie rentgenovskogo izlucheniia na kinetiku 5-iod-2'-dezoksiuridina v opukholi.

Within the interval of 0.25-168 h after intraperitoneal administration of 125I-iodo-desoxyuridine (IDUR) to mice with inoculated melanoma B-16 or sarcoma-180 the kinetics of a radionuclide label (RL) in both tumors was almost the same; the difference were of quantitative nature only. X-ray radiation resulted in an increase in the radioactivity change rate on the first section of the curves of RL clearance, plotted in semilogarithmic coordinates, in both tumors. Differences in the rates in the study groups of animals irradiated at doses of 2; 10 and 20 Gy and their distinctions from the control group were significant. Proceeding from the modern concept of IDUR metabolism a simple mathematical model has been devised where it is assumed that at the initial moment t = 0.25 h general radioactivity measured in vivo over a tumor, results from radioactivity incorporated in DNA which is constant for each irradiation regimen up to a certain time, and the radioactivity of iodide which is released from the body by the exponential law. A formula has been deduced associating the rate of a decrease in general radioactivity on the first segment of a kinetic curve of RL clearance with the level of the label incorporation in DNA. Thus, the applicability of RL IDUR was shown for establishing the quantitative relations between the proliferative ability of a tumor and an irradiation dose.

[125I-iododeoxyuridine in the reaction of experimental tumors to irradiation]. / 125I-ioddezoksiuridin v reaktsii éksperimental'nykh opukholei na obluchenie.

A study was made of the kinetics of 125I-iodo-desoxyuridine clearance after x-ray irradiation of experimental tumors sarcoma-180 and melanoma B-16 at doses of 2, 10, 20 and 40 Gy. Change in the level of radioactive label within the time interval of 0.25-48 h was approximated by exponential function (r2-0.92-0.98) or straight lines on a graph in the semilogarithmic scale. Their inclination angles differed significantly for the above doses. Correlations were obtained between the ratio of the rates of change of radioactivity in the irradiated and control tumors within the interval of 0.25-48 h after the administration of 125I-iododesoxyuridine and parameters which characterized growth of the above tumors in various irradiation regimens. The analytical expressions obtained are applicable to quantitative assessment of a tumor response to irradiation.

[Irradiation of cancer patients through the grid diaphragm]. / Obluchenie onkologicheskikh bol'nykh cherez reshetchatuiu diafragmu.

Irradiation through a grid diaphragm has some advantages. However, further development of this method is complicated by the absence of sufficiently substantiated theoretical principles using physical-dosimetric as well as radiobiological approaches. The correct presentation of the clinical data and precise statistical data processing are necessary, especially while comparing this method with other radiotherapeutic methods.