Leukopenia prognosis during radiation therapy in patients with Hodgkin's disease.

The investigation goal of the present report is to use the early post-radiation peripheral blood DNA content changes during radiotherapy (RT) of cancer patients for the prognosis of the subsequent leukopenia value. Twenty-three primary patients with II-III stage Hodgkin's disease were treated at the linear accelerator of 15 Mev electrons by usual fractionation to total 40 Gy dose. The blood DNA content was fluorometrically determined by 4', 6-diamidino-2phenylindole before treatment, then 24 hrs after the 1st irradiation dose, in the middle and at the end of RT course. Retrospective analysis of obtained data demonstrated, that the first group of patients, having blood leukocyte levels above 3 x 10(9)/l at the end of RT, revealed an average blood DNA concentration decrease only after the middle of treatment course. The second group of patients, having at the end of RT severe leukopenia, showed an approximately twofold decrease of the DNA concentration after the first irradiation in 62% of cases. The biochemical change was not accompanied by a proportional decrease of the leukocytes amount. The DNA content fall, at the middle and at the end of RT course, was conditioned both by lymphocytes and granulocytes. These changes were not practically interfaced with plasma changes. Thus, a given biochemical criterium may be used as a sensitive index for the prognosis of leukopenia values after the RT beginning. Such a conclusion was confirmed by in vitro test-irradiation of blood specimens of primary patients with Hodgkin's disease. A significant correlation was found between the new index and the level of leukopenia of the patient's blood during post-treatment course.