Total-body irradiation and bone-marrow transplantation - first observations on clinical tolerance

About 50 000 bone-marrow transplantations (BMT) are performed annually at the present stage in numerous clinical centers all over the world. The Bulgarian experience in total-body irradiation (TBI) with following BMT is rather scarce. The routine TBI procedures in the oncological practice in the country date back just to 2001. The aim of the present publication is to describe the Bulgarian experience and the first impressions from the clinical tolerance of the total-body irradiation (TBI) with subsequent allogeneic peripheral stem cell transplantation (PSCT). Patient characteristics are presented in detail, including their distribution with respect to sex, age, primary diagnose, recurrence number till BMT, patient status during BMT performance (clinical hematological remission or relapse), as well as the basic parameters of the conditioning regime including TBI with subsequent allogeneic PSCT. The position of the patient and the applied radiotherapeutic equipment are described as well as the TBI schemes, respectively 5 fractions of 2 Gy per day for two patients and 3-day irradiation with 6 fractions (two fractions with a 6-hour interval between them) for the rest of the patients. The total dose (TD) of 10 Gy is realized for all patients. The clinical tolerance of 7 patients subjected to TBI and allogeneic PSCT is discussed. All patients were tolerable to the TBI treatment and had no serious problems. The radiotherapy was interrupted only in the case of the first two patients due to slight gastro-intestinal reactions. The first days of radiation were accompanied with a light degree of headache, nausea and vomiting, which were successfully overcome by granisetron. Diarrhea syndrome and mucositis to the II-III degree were developed subsequently without parotitis development. On the days 0 and +1 of the clinical protocol transplantation was realized of non- T-cell-depleted grafts (in 5 patients) and T-cell-depleted grafts (in 2 patients), which had no serious complications in 5 of the cases. The transplantation was accompanied by allergic reactions in two patients. Acute GvHD was developed in only one patient. No pneumonitis was developed and we attribute this to the fact that the planned dose in the lungs was not exceeded - it was verified to be 8 Gy by in vivo measurements. Powerful antibiotic, antifungal, antiviral, substituting and symptomatic therapy was accomplished in all patients. No clinically displayed infections were observed in 6 of them despite of the presence of positive uro- and coprocultures. Six patients were discharged in good general condition within the interval of 16 to 30 days after the transplantation with compensated hematological parameters and stable transplant effect.The aspiration for widening the scope of indications for TBI treatment with subsequent allogeneic PSCT continues to be in the bases of the routine practice in the country and the clinical observations proceed in this context. Key words: total-body irradiation. bone-marrow transplantation. clinical tolerance