[en] The authors used electron microscopy, thrombo-dynamo-graphy and spectrophotometry, to study the damage caused by X rays on the fibrinogen molecule and fibrin-formation process. This process is highly disturbed by increasing doses of irradiation from 0 to 3.10⁵ roentgen. Electron microscopy observation shows interesting data on the structure of the plug, formed by irradiated fibrinogen solution. This study also lead the authors to propose a new model of the fibrinogen molecule and a schema explaining observed striations and granular appearance of the fibrin fibers surface. (authors)

[en] Faced with increasing indications for the use of iodine-131 labelled lipiodol in the treatment of hepatocellular carcinoma (HCC), it appears essential to develop an individualized dosimetrY so we can predict the potential effectiveness of this treatment and adjust the activity to be injected. We developed a dosimetric protocol based on imagery and dedicated to calculation of the tumoral dose during the treatment of hepatocellular carcinoma by iodine-131 labelled lipiodol. This concept was developed on a SPECT- CT gantry, and integrates corrections for the phenomena of attenuation, diffusion and dead time. The dose is calculated according to the formalism proposed by the Medical Internal Radiation Dose Committee (MIRD). This protocol was applied to a series of 41 patients in the framework of a retrospective study. The results obtained in terms of biodistribution are compatible with previously published data. The total biological response rate is 42% (n= 41) for the first treatment and 43% for the second (n=25). Morphologically, there is a 17% response to the first treatment and 35% to the second. We find a correlation between the tumoral absorbed dose, calculated in tomo-scintigraphic mode, and the morphological response to the first treatment (p = 0.0071). Moreover, a tumoral absorbed dose of 280 Gy appears to be an effective dose threshold in our population. These results are promising insofar as they enable us to predict the effectiveness of the treatment by Lipiocis. (authors)

[en] Oral communications relative to radiotherapy are presented here. Evaluation of radioimmunotherapy by 90-Y-Ibrittumomab tiuxetan by PET FDG, treatment against pain in bone metastases, estimation of personnel exposure during radiotherapy ( iodine 131, samarium 153, yttrium 90), dosimetry evaluation and response of brachytherapy are the principal subjects of these communications. (N.C.)