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Biomedical subjects

S I Tkachev

Publications and source records attributed to S I Tkachev.

33 records · Page 2Linked to original sources
PubMed1991

[Radiation treatment of bladder cancer using different fractionation regimens].

The paper is devoted to a follow-up of 177 bladder cancer patients. The problems of providing radiotherapy with the use of hyperfractionation of a radiation dose were discussed. Despite an increase in a tumor dose by 15%, no increase in the number and expression of local radiation reactions is observed. Enhanced therapeutic efficacy was observed, particularly in cases of locally advanced tumors (T3). Three years after conventional radiotherapy 44% of the patients were alive, after hyperfractionated irradiation--69%.

Adult↗
PubMed1989

[The prognostic significance of the rate of growth in the radiation treatment of esophageal cancer].

Biological growth parameters (tumor volume, doubling time with regard to a tumor site, a macroscopic type of tumor growth and semiregression time in radiotherapy or in its combination with radiomodifying agents) were analyzed in 180 esophageal cancer patients. Immediate and short-term results of therapy were shown to be in direct relation to the above factors. The most favorable prognosis is to be expected in the group of patients with fast growing tumors (doubling time less than or equal to 64 days) Unless a tumor of the esophagus has become large (a tumor volume not more than 68.6 cm3), it means exophytic or mixed growth, and radiotherapy is recommended in combination with radiomodifying agents, first of all with local hyperthermia.

Combined Modality Therapy↗
PubMed1989

[Prognosis and results of radiotherapy of esophageal cancer with the use of radiomodifiers].

The paper is concerned with a retrospective analysis of the results of therapy of 277 esophageal cancer patients who received radiotherapy alone or in combination with radiomodifying agents depending on the results of clinico-instrumental investigations. Correlation of immediate effectiveness of radiation therapy and duration of a case history, macroscopic type of growth of a tumor, its dissemination, a degree of tumor regression at a dose of 35-40 Gy, the frequency and severity of radiation esophagitides was confirmed. A degree of the influence of these factors was less marked in the use of radiation therapy combined with radiomodifying agents. Life duration is proportional to a degree of tumor regression achieved by the end of a radical course of radiation therapy.

Carcinoma, Squamous Cell↗
PubMed1983

[Method of gamma teletherapy in prostatic cancer].

Three variants of gamma-beam therapy of prostatic cancer were worked out on the basis of a thorough topometric preparation, an analysis of dose distributions using computer, and taking account of tumor dissemination. It has been shown that moving one- or two-field gamma-beam therapy is indicated in cases when tumor lies within the limits of the prostate only. When it affects regional lymph nodes the combination of moving gamma-beam therapy with static 4-field cross irradiation with the ratio of doses from the front and back fields 2:1 is recommended. When tumor involves the nearest lymphatic collectors gamma-beam therapy is supplemented by estrogens with stage-by-stage irradiation of primary tumor, regional lymph nodes (by the above schemes) and the paraaortal group of lymph nodes from 2 opposite shaped fields, a focal dose to these nodes being 30-40 Gy only. The summary focal dose to the regional lymph nodes is 45-50 Gy, to primary tumor 65-70 Gy. The above variants of gamma-beam therapy were used for the treatment of 69 patients with prostatic cancer, Stages II-IV. Not a single patient developed marked reactions and late complications 6-36 mos. after therapy, 61% of the patients lived over 3 yrs.

Gamma Rays↗
PubMed1982

[Results of rotational gamma teletherapy of prostatic cancer].

Remote rotational gamma-therapy was carried out in 36 cases of prostatic cancer. Hormonal treatment was given to 27 patients before gamma-therapy. There was a 2-4 week interval in the course of treatment. Single focal dose was 2 Gy and total dose--56-71 Gy. Complete resorption of tumor was in 26 and reduction in tumor size in 9 patients. Recurrences were registered in 9 out of 26 cases within the first two years after exposure termination. Bone metastases were observed in 7 out of 36 cases within 9-48 months after treatment. Hormones were administered to patients with metastases as well as cases of incomplete cure and recurrences. The patients were followed up during periods ranging from 6 months to 7 years. Survival for more than 3 years was recorded in 61% of cases. No radiation injury was observed. Rotational remote gamma-therapy may be used for treatment of local prostatic cancer.

Aged↗
PubMedDate not supplied

[Hyperthermia as a method for treating prostatic adenoma].

Local microwave hyperthermia was used in 15 patients aged 60 to 76 years with prostatic adenoma on an inpatient (n = 8) and outpatient (n = 7) basis. Severe clinical symptoms of prostatic adenoma was considered indication and urinary and prostatic stones were contraindications. Every patient received 6 hyperthermia treatments (41 to 42 degrees C) with a 915 or 460 MHz device. Adenoma of the prostate was treated twice a week. An interval of 3-4 days was used to avoid thermic tolerance. The treatments were well tolerated. Prostatic size was reduced by 15.2 cm2 in 11 patients and unchanged in 1 patient. Three patients required surgery 2 weeks after treatment withdrawal because of adenoma distension with residual urine and 3 patients were operated on for cystostomes. The overall effect of microwave hyperthermia on prostatic adenoma was induction of focal sclerosis in adenoma. This treatment improved uroflowmetric findings and abolished residual urine. Hyperthermia is a reasonably safe conservative option for inoperable patients with prostatic adenoma.

Aged↗
PubMedDate not supplied

[Radiation exposure and local hyperthermia in the treatment of prostatic cancer].

During the recent two decades, radiation therapy has become a major intervention for prostatic cancer, especially in patients without remote metastases. Most recently local hyperthermia has been recruited for selective potentiation of radiation effects on the tumor. This study involved 81 patients with the prostatic cancer T2-4NxM0. All patients had adenocarcinoma of variable malignant potential. Group 1 (n = 24) received only megavoltage radiation therapy while Group 2 (n = 57) was additionally treated with local microwave hyperthermia. A Yalik-F device (USSR) with electromagnetic frequency 460 MHz was used. Special intracavitary irradiating aerials were designed and employed. While symptoms of neoplasia are lacking 2 years following radiation therapy in 13 of 24 patients of Group 1, this response was obtained in 10 of 12 patients of Group 2 (54 +/- 5% and 83 +/- 10%, respectively). Two-year survival rates after radiation and thermoradiation therapy were 81 +/- 8% and 92 +/- 8%, respectively. Asymptomatic progress is seen in 40 +/- 10% and 75 +/- 12% of the patients. These results suggest that local hyperthermia as an adjuvant to radiation therapy will improve the efficacy of therapy in patients with prostatic cancer.

Adenocarcinoma↗
PubMedDate not supplied

[The comparative efficacy of radiation and thermoradiation treatments in prostatic cancer].

Short- and long-term results of stage-III and -IV prostatic cancer treatment were compared in 147 patients without distant metastases. 38 patients were exposed to radiation, 109 patients underwent radiation treatment and local microwave hyperthermia. The response of the primary tumor was evaluated at palpation, ultrasonic investigation and computed tomography. Adjuvant local hyperthermia enhanced antitumor activity of the treatment raising the rate of a complete response from 69% on radiotherapy alone to 94% on thermoradiotherapy, 5-year survival in prostatic cancer stage III and IV increased also from 48 to 65%.

Aged↗