[Combined radiotherapy of esophageal cancer]. / Sochetannaia luchevaia raka pishchevoda.

The paper is concerned with the results of combined radiotherapy of 60 esophageal cancer patients. Indications for combined radiotherapy were the minimum lumen of the esophagus (8-10 mm), limited local spreading of a tumor, and the absence of distant metastases. Among the patients there were 46 men, 14 women, their mean age was 56-8.3 yrs. The mean duration of life of the dead patients was 16.2-7.2 months. No cardiac or pulmonary complications were observed. The 3-year survival rate was 26.4-6.9% and the 5-year survival rate was 17.8-6.1%.

[Planning mobile gamma therapy of cervix cancer]. / Osobennosti planirovaniia podvizhnoi gamma-terapii raka sheiki matki.

Moving irradiation of cervical cancer is widely used in radiogynecological practice, mainly as a telecomponent of combined radiation therapy. Its advantages over static irradiation are reduced exposure of the adjacent organs, the absence of skin complications, and a possibility of simultaneous exposure of a primary focus and lymph outflow viae. Biaxial sectoral irradiation was regarded as the most effective method. In order to increase the accuracy and improve the individualized design of moving irradiation according to this method the authors proposed that echotomography be used to determine the depth of the vibration axis. The thickness of subcutaneous fatty tissue was taken into account within the irradiated field in each case. The existing calculating and echotomographic methods for the determination of a position of the vibration axis were compared. Divergence between them was absent in 65% of cases, divergence of up to 1 cm was noted in 28%, up to 2 cm in 31%, up to 3 cm in 20%, and over 3 cm in 14%. Differences were statistically significant. Taking into account a high dose gradient in the sagittal plane the proposed method will make it possible to avoid overirradiation of the bladder and rectum.

[Prevention of radiation injuries during multifractionation in radiation therapy]. / Profilaktika luchevykh povrezhdenii pri mul'tifraktsionirovanii v luchevoi terapii.

A radiobiological substantiation of a method of multifractionation and a review of the results of its clinical application are presented. The authors have developed a method to calculate a cumulative radiation effect and the TDF factor in radiation therapy with multiple dose fractionation in the form of several sessions daily. This method can be used to prevent the radiation-caused complications.

[Calculation of the dose distribution with time in the planning of radiation treatment]. / Uchet raspredeleniia dozy vo vremeni pri planirovanii luchevogo lecheniia.

Until recently the effect of a dose fractionation regimen was disregarded in radiation therapy planning. A devised method of the calculation of iso-TDF-dose maps made it possible to obtain iso-effective distributions where radiation exposures in different dose fractionation regimens are presented in the form of isoline in TDF units. The method of the calculation of iso-effective maps allowed us to analyse the effect of the procedure of the implementation of a radiotherapeutic plan and the conditions of dose rate fixing. The author cites by way of an example the calculation of a 3-field static irradiation of esophageal cancer with 5 fractions a week. All possible variants of the implementation of this therapeutic plan were studied. Daily irradiation of all the planned fields has been shown optimum. This conclusion is corroborated by the literature data. The absolute value of the TDF factor in the adjacent healthy organs and tissues increases noticeably using in the calculations isodose curves fixed to the dose in the focus depth as compared to the dose fixing on the surface. Isoeffective maps can be successfully used for an analysis of clinical and therapeutic results.