Comparative study and clinical implementation of two breathing-adapted radiotherapy techniques: dosimetric benefits for lung cancer treatment]

Breathing can lead to organ motions up to several centimeters. For radiotherapy of lung, these motions are generally taken into account by adding a specific margin around the target. Thus, treated volumes are often too large to allow for the high-dose values requested for local control. To manage respiratory motion, deep-inspiration breath-hold technique (DIBH) and gated radiotherapy are starting being used clinically. DIBH consists in asking the patient to perform breath-hold during the treatment and the image acquisition, DIBH level being measured by a spirometer. Gated radiotherapy consists in treating the patient at a certain phase of the free breathing. Linac is synchronized with the motion of a marker located on the patient chest. Planning images are obtained by a four-dimensional CT (4D-CT) using the same marker. We have assessed the value of these two methods. For lung treatment, compared to a standard treatment, toxicity reduction was mainly due to the lung total volume increase. It is therefore more significant for breath-hold approach. It is also due to the reduction of safety margins, which is similar for both methods. These two techniques, which have specific advantages and drawbacks, are used routinely at Curie Institute for a large proportion of lung patients, but also for some breast, liver or even Hodgkin disease treatments.     

Isolated right ventricular dysfunction in systemic sclerosis: latent pulmonary hypertension?

Right ventricular function is frequently abnormal in patients with systemic sclerosis, but whether this is related to pulmonary vascular complications of the disease is unclear. Standard echocardiography with tissue Doppler imaging was performed at rest and during exercise for the study of right ventricular function and pulmonary circulation in 25 consecutive systemic sclerosis patients and in 13 age-matched healthy controls. When compared with the controls, the patients had no difference in systolic right ventricular pressure gradient, but a decreased pulmonary flow acceleration time, and increased right ventricular free wall thickness and end-diastolic dimensions. At the tricuspid annulus, the E maximal velocity was decreased (8.9 +/- 4 versus 11.7 +/- 2.3 cm.s(-1)) and the isovolumic relaxation time corrected to RR interval was increased (6.5 +/- 2.9 versus 4.5 +/- 2.5%). The tissue Doppler imaging profile at the mitral annulus was similar in both groups. At exercise, 18 patients had a decreased maximum workload and cardiac output, no change in systolic right ventricular pressure gradient, but an increase in the slope of pulmonary artery pressure/flow relationships. These results suggest that patients with systemic sclerosis may present with latent pulmonary hypertension as a likely cause of right ventricular diastolic dysfunction, as revealed by stress echocardiography and tissue Doppler imaging.     

Radiochemical dates obtained by alpha spectrometry on fossil mollusk shell from the 5e Atlantic shoreline of the High Atlas, Morocco.

The reported radiochemical results obtained on 77 samples collected from Moroccan fossil beaches assumed to be deposited during the above present sea-level high stands corresponding to 5e climatic stage, and on 12 present and Holocene samples, are discussed in order to judge the age validity. Contrary to the Holocene shells where (238)U contents are low and (234)U/(238)U are in agreement with sea-water ratio, the 5e results vary considerably irrespective of species and calcite content of samples. Because of the open-system possibility, the (230)Th/(234)U ages based on shell samples should be interpreted as minima for any studied shoreline discussed in the light of geological data and several shells analyses.     

Pontine veins. MRI cross-sectional anatomy

Summary The pons is covered by a rich venous network offering numerous vascular landmarks in MRI and during surgery. We present an original study of the veins as they appear on MR multiplanar scans after gadolinium IV injection. This prospective study is based on 40 consecutive patients with normal posterior fossa structures. One of the major venous collectors follows the pons: the superior petrosal v. was identified on MRI in 95% of our cases. Its hooklike extremity drains into the superior petrosal sinus. The inferior petrosal v. was never identifiable. The superficial pontine venous network are identified in 72.5% of cases in the axial plane and were organised in longitudinal and transverse collectors, whose MR aspects are presented here.

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Les veines du pont. Anatomie sectionnelle en IRM

Résumé Le pont, enveloppé des citernes subarachnoïdiennes, est parcouru à sa surface par de nombreux vaisseaux qui constituent autant de points de repère topographiques en IRM que de rapports chirurgicaux. Nous présentons une étude de l'anatomie veineuse en coupe telle que l'IRM la révèle après injection de Gadolinium. Cette étude prospective comporte 40 patients indemmes de lésion de la fosse crânienne postérieure. Le pont est longé par un des collecteurs majeurs du tronc cérébral : la v. pétreuse supérieure, identifiée dans 95 % des cas. Elle se jette par un crochet caractéristique dans le sinus pétreux supérieur. La v. pétreuse inférieure n'a jamais été reconnue. Les vv. pontiques forment un réseau maillé visible dans 72,5 % des cas en coupes axiales et comportant des axes transversaux et longitudinaux dont les critères d'identification sont présentés selon le plan de coupe.

     

Biomarkers for toxicity and metabolic abnormalities of the main severe poisonings. Clinical and toxicologic symptoms. Conservative determination

The members of the joint group "Toxicology and Clinical Biology" of the French Society of Clinical Biology (SFBC), the French Society of Analytical Toxicology (SFTA), and the Society of Clinical Toxicology (STC), suggest guidelines to meet the requirements of clinical biologists who are not specialized in toxicology. Based on good laboratory practice they propose a number of guidelines. Three synthetic tables have been established. They are not only toxicity biomarkers and metabolic disorders associated with the main severe intoxications, but also clinical signs that are observed during these intoxications, finally biological sampling as a precautionary measure. The table also takes into account approximately fifty xenobiotics: main clinical signs emergency, identification or quantification of the suspected product, useful biological markers, therapeutic, quantitations necessary to take into consideration patient care, and poison antidotes, are described. Recommendations regarding medical and forensic techniques are also proposed by the group. It is also necessary to collect and store biological samples when the individual patients are in charge. These samples will be analyzed or not depending on the individual case history.