Studies of metronidazole radiosensitizing effect in radiation treatment of patients with oral cavity cancer.

Clinical observations of 26 patients with tongue, oral cavity and oropharyngeal cancer receiving telegammatherapy by dynamic dose fractionation scheme in combination with metronidazole (MZ) and of 38 patients from control group treated by identical schedule without MZ suggest that MZ favors increasing of the radiation damage in tumors of those sites without changing the character or intensifying early radiation reactions. After oral administration of MZ in single doses of 5-6 g/m2 it reaches its maximum in the blood serum within 2-4 h. When the total dose of 30-60 g of MZ was used, a marked toxic effect manifested by gastrointestinal symptoms was observed in 33.3% of patients. MZ has a negative effect on liver functions, however, changes in biochemical tests illustrating it, are reversible and within the norm. Simultaneous studies of biopsy material from 22 patients (11 from each group) in terms of proliferation activity showed that oral cavity tumors contain a significant portion of proliferating cells which notably decrease in the course of radiation therapy. To a greater extent that decrease is marked after irradiation with MZ.

Three-year results of surgical and combined treatment of lung cancer with a preoperative radiotherapy.

In this paper the analysis of immediate results of clinical material is given which has been accumulated by participants of the joint investigation in some CMEA member countries (Project 3-9.1.1 of the Lung Cancer Program; Bulgaria, Hungary, Poland, USSR, Czechoslovakia) with the aim to study the effectiveness of one of the variants of combined treatment of patients with differentiated forms of lung cancer. Combined treatment received 286 patients, 231 patients (control group) were treated surgically. It is concluded that the preoperative radiotherapy using the method of the intense concentrated course does not complicate the operation itself and is not reflected in the nature and frequencies of intraoperative complications. However, in combination with the subsequent surgical intervention, it significantly elevates the number of postoperative complications, particularly of those of purulent nature (bronchial fistula, intrapleural empyema) and also the lethality. The difference between the groups in this respect is particularly significant at State III of the disease. Late results were studied in 379 patients (in 221 of them after a combined treatment and in 158 after surgical treatment). For more than 1, 3 and 5 years survived 76.5, 49.4 and 34.48% (combined treatment) and 77.2, 41.2 and 20.7% (surgery), respectively. The differences between the groups in favor of the combined treatment are due to patients with Stage III planocellular carcinoma.

Results of radiotherapy and combined radiotherapy and chemotherapy of inoperable lung cancer.

In this study there is presented a comparative analysis of immediate results after radiotherapy and combined treatment (radio- and chemotherapy) in 174 patients with highly differentiated inoperable lung cancer. The data were provided by participants of a joint investigation in some CMEA member countries (Hungary, USSR, Czechoslovakia) during the period of 1976 to 1980. In the randomized study radiotherapy (a total dose of 60 Gy) was applied in 98 patients, radiotherapy with chemotherapy (methotrexate and 5-fluorouracil) was applied in 76 patients. The comparative analysis showed that the employment of complementary chemotherapy tend to improve the immediate therapeutic effects. In the case of highly differentiated planocellular carcinoma a pronounced positive effect was seen in 48.6% of patients as compared to the 31.2% of those treated with radiotherapy alone. Nevertheless, with respect to survival rate prolongation, these differences are not manifested in favor of the combined method of treatment. After a conservative treatment (radiotherapy and radiotherapy in combination with chemotherapy) of patients with differentiated types of inoperable lung cancer there was a one-year survival rate of 55.7%, 17.27% of the patients survived for 2 years, and 8.55% for 3 years. In radiotherapy applied alone as in the combined method as well, a direct dependence of survival rate prolongation on immediate therapeutical effects was detected. For more than 1 year survived 49 patients (73.1%) out of 67 exhibiting pronounced immediate effects, and for 3 years survived 8 patients out of 9.

Proliferative activity and radiosensitivity of human tumors.

On surgery material and biopsies from human tumors of various types investigation of labeling index and growth fraction in vitro, cell survival and cell population kinetics in diffusion chambers and changes in the cell kinetic parameters after irradiation were performed. The analysis of results obtained using the diffusion chambers and in vitro system demonstrate variability in labeling index within tumors of various type, individual differences and variation within the same tumor. Significant variability of growth fraction in individual tumors was also noted, however, in many instances, the most of cells in tumor were not proliferating. The growth fraction in gliomas and tumors of the floor of mouth was greater in tumors with high labeling index, in patients with a short tumor history and in patients with the short nonrelapse period. In the same groups of tumors changes of labeling index growth fraction during radiotherapy were compared with the therapeutic response of tumors. It can be concluded that the initial parameters of proliferative activity (labeling index and growth fraction) did not determine the radiation response of tumors but the dynamics and the intensity of their changes during the treatment were more informative in this respect. Complete regression of tumor may be expected only with decrease of labeling index and growth fraction.