[The effect of preoperative radiation therapy on the results of the combined treatment of esophageal cancer]. / Vliianie preoperatsionnoi luchevoi terapii na rezul'taty kombinirovannogo lecheniia raka pishchevoda.

The authors resorted to multifactor comparative analysis of the results of surgical (218) and combined (413) treatment of patients with thoracic esophageal cancer to study the interrelationship of the main factors, determining a cancer stage, their prognostic value, and a degree of influence of preoperative modalities on these factors. Preoperative irradiation was shown to increase resectability of the esophagus with tumor extent over 5 cm and to improve the prognosis of disease.

[Present trends in the development of radiotherapy]. / Sovremennye napravleniia sovershenstvovaniia luchevoi terapii.

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.

[Prospects of development of radiotherapy in an oncological clinic]. / Perspektivy razvitiia luchevoi terapii v onkologicheskoi klinike.

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.

[Combined treatment of cancer of the thoracic segment of the esophagus]. / Kombinirovannoe lechenie raka grudnogo otdela pishchevoda.

The results of an analysis of combined treatment of 391 cases of carcinoma of the thoracic segment of the esophagus are presented. Three stages of treatment--abdominal, radiation and surgical--are discussed.

[Method of dynamic dosage fractionation in preoperative radiation therapy of esophageal cancer]. / Metodika dinamicheskogo fraktsionirovaniia dozy pri predoperatsionnoi luchevoi terapii raka pishchevoda.

Dynamic dose fractionation in preoperative radiation therapy in 53 esophageal cancer patients comes down to the following: in the first 3 days a daily tumor dose was 4 Gy, then a daily dose was 2 Gy with a summary focal dose up to 36-42 Gy. Therapeutic results for 127 patients served as control using the routine fractionation schedule: 2 Gy daily (5 times a week) up to a summary focal dose of 40-45 Gy. The irradiated area included almost the entire length of the organ with the regional lymphatic collector. Good tolerance of the method of dynamic dose fractionation was noted: no increased frequency and severity of radiation reactions and complications were noted. The use of the new method made it possible to reduce the periods of preoperative irradiation and rehabilitation. Considerable tumor regression after the use of the above method was observed in 69 +/- 8.7% of the patients, in the control group in 38.9 +/- 8.2% only. A simultaneous increase in the degree of radiation injury of tumors was noted in the study group (3rd-4th degree of radiation pathomorphism in 89.5 +/- 4.5% of the tumors); in the control group in 70.4 +/- 4.4%. Resectability did not differ significantly in both groups. The use of dynamic dose fractionation brought about improved results of combined treatment in general: an increase in the 2-year survival rates by 1.5 himes (59.2 +/- 6.7% as compared to 34.7 +/- 4.2%) was noted.

[Pharmacokinetics and the effects of metronidazole during its use as a radiosensitizer]. / Farmakokinetika i deistvie na organizm metronidazola pri ispol'zovanii ego v kachestve radiosensibilizatora.

During gamma-beam therapy (40-60 Gy) a study was made of the content of metronidazole (MZ) in the blood of 20 patients with oral mucosa cancer and 12 patients with esophageal cancer depending on a mode of its administration. A MZ effect on liver and renal function was studied. MZ was administered to the patients with cancer of both sites on the first 3 days of radiation therapy 3 h before an enlarged fraction of 4 Gy, estimated at 145 mg per 1 kg body mass (8-10 g) per os or via a gastrostoma and 15 g in rectal administration. In the patients with oral mucosa cancer after the administration of MZ per os its level which was sufficient for radiosensitization, was achieved after 2 h and remained for subsequent 4 h with maximum accumulation of 262 +/- 22 micrograms/ml in the blood serum 3-4 h after administration. In 24 h there remained 84 +/- 9 micrograms/ml of MZ in the blood (32% of its maximum level). In the patients with esophageal cancer after MZ administration via the gastrostoma, the nature and time course of drug accumulation in the blood was identical, however accumulation maximum was lower and reached 219 +/- 25 micrograms/ml. In the patients with esophageal cancer after MZ rectal administration, its level in the blood was 118 micrograms/ml only and did not achieve a therapeutically effective level. In repeated administration of MZ per os or via the gastrostoma its accumulation by 25-30% was observed. MZ caused a transient increase in the permeability of the cell membranes of the liver and the suppression of its protein-forming function. It is assumed that the lowering of MZ repeated dose by 20% will cause a decrease in the drug accumulation in the body and the degree of a toxic effect with maintaining its therapeutically effective level in the blood and tumor.