[Combination gamma-therapy of cancer of the oral mucosa]

The authors analysed the results of therapy of 72 oral mucosa cancer patients who had received combined modality radiotherapy using at the stage of intracavitary irradiation sources of 60Co of a raised dose rate on the afterloading AGAT unit. Forty four patients received irradiation as part of combined modality therapy, 28 were treated by irradiation only. Two variants of combined modality radiotherapy were employed: gamma-beam and intracavitary irradiation was given simultaneously on the same day; consecutively alternating gamma-beam (on the 1st day) and intracavitary (on the 2nd day) irradiation. The most effective summary focal dose values in preoperative combined irradiation were 40-45 Gy (with the ratio of the contribution of gamma-beam therapeutic doses of 30-35 Gy and intracavitary doses of 10-15 Gy) and in radiotherapy used alone 75-80 Gy (with the ratio of irradiation components being 50-55 Gy and 25-30 Gy respectively). Complete tumor resorption in combined modality radiotherapy used independently was achieved in 19 out of 28 patients (67.8%). In combined treatment tumor regression by more than 50% after preoperative irradiation was achieved in 65.9% of the patients. Tumor recurrences were noted in 5 of 44 (11.3%) patients in combined treatment and in 3 out of 19 (15.7%) in radiotherapy used alone. Five-year survival rates calculated with the help of life tables were 55.7 +/- 10% after combined treatment and 48.7 +/- 11% after radiotherapy used alone. Clinical evidence indicated the advantages of combined modality radiotherapy with simultaneous intracavitary and gamma-beam irradiation.