[en] The early response of blood cells to irradiation has been studied in leukemia patients who received total body irradiation (TBI) prior to cyclophosphamide and bone marrow transplantation. After a single session treatment (10 Gy in 4 h) the most dramatic variation was observed in the granulocytes. At the end of the irradiation their concentration was 2 to 6 times higher. Because of a subsequent rapid decline, the peak may be overlooked if the blood counts are delayed. Lymphocytes decreased to 50% at the end of the single session TBI and continue to decrease exponentially, with a half time of 30 h. During a fractionated irradiation (11 x 1.2 Gy in 4 days) the lymphocyte number dropped to 60%, 13 h after the first fraction and this decline continued with a half time of 30 h during the treatment. From the data obtained in vivo, a lymphocyte D₀ value of 1.2 Gy was computed. The lymphocyte subsets (B.T. OKT4 OKT8) did not exhibit different radiosensitivities either in vivo or in vitro. The disappearance of lethally hit lymphocytes from the blood exhibits a biphasic kinetic: 50% of the cells disappear in a few hours and 50% with a half time at 30 h. Lymphocytes irradiated either in vitro or in vivo when in culture disappear slowly, contrasting with the in vivo findings. It may suggest that lethally hit lymphocytes are quickly removed from the circulating pool in vivo. (Auth.)

[en] This paper reports that a sufficient amount of data have been accumulated to accept MIBG scans as a major modality in neuroblastoma staging, due to the tumor specificity of the tracer, playing the same role in neuroblastoma as has radioactive Iodide for four decades in differentiated thyroid cancer. The use of MIBG is simple and safe, especially when labelled with pure I-123. Even if in most cases it is possible to stage correctly a neuroblastoma patient with a CT and bone marrow aspirates or biopsy, MIBG scans provide more accurate information on the tumor burden in the whole body and may indicate additional CT images at a distance from the primary or additional bone marrow biopsies. When positive, MIBG scans replace conventional TC-99 m HMDP bone scans, and may reduce the frequency of CHBMS. When repeated during therapy, MIBG scans provide valuable information to quantitate a partial response and to confirm a complete response

No abstract available

[en] Malignant non-Hodgkin lymphomas are a neoplastic proliferation of lymphoid cells whose clinical manifestations are extremely variable. All tissues can be affected. There may be localization in lymphoid organs (Waldeyer's ring, spleen, digestive tract), other localizations (lungs, pleura, liver, bone marrow, central nervous system) and unusual localizations. Although bone marrow is often affected, bone involvement is very rare in the early stages of the disease. This report concerns the radiological study of two disseminated malignant non-Hodgkin lymphomas affecting only the bone in children. (orig.)