Quantification of respiration-induced abdominal tumor motion and its impact on IMRT dose distributions

PURPOSE: The treatment of moving targets with intensity-modulated radiotherapy may introduce errors in dose delivery. The motion of tumors in the abdomen was studied using quantitative fluoroscopic analysis, and the effect on dose delivery to the target was studied. METHODS AND MATERIALS: Fluoroscopy sessions for 7 patients with pancreas or liver tumors and fiducial clips were recorded, converted to digital format, and analyzed to quantify the characteristics of tumor motion. Intensity-modulated radiotherapy plans were generated for 3 patients (a total of five plans), and the dose-volume histograms for the target volume were compared between plans with and without tumor motion. RESULTS: The average magnitude of the peak-to-peak motion for the 7 patients in the craniocaudal and AP directions was 7.4 mm and 3.8 mm, respectively. The clip motion varied widely, because the maximal clip excursions were about 47% greater than the average clip excursions for each patient. The inclusion of tumor motion did not lead to a significant degradation in the target dose-volume histogram for four of five treatment plans studied. CONCLUSION: The amount of tumor motion for most patients in this study was not large but could, in some instances, significantly degrade the planned target dose-volume histogram. For some patients, therefore, motion mitigation or intervention during treatment may be necessary.     

Update on surgical treatment for endometrial cancer

In the USA, carcinoma of the endometrium consistently ranks as the most common malignancy of the female genital tract. Since the majority of cases present with abnormal clinical symptoms, these patients are typically identified at an early, curable stage when the neoplasm is still confined to the uterus. Surgical removal of the organ involved remains the cornerstone of treatment for this disease, and in light of this, surgery has replaced clinical examination as the staging modality of this malignancy. Surgery also appears to have a role in the management of advanced and recurrent disease. The surgical treatment of this disease is the focus of this review.     

Cost-effectiveness of magnetic resonance imaging and enteroclysis in the diagnostic imaging of Crohn's disease

OBJECTIVES: To compare the cost-effectiveness of magnetic resonance imaging (MRI) and enteroclysis in patients with Crohn's disease (CD). METHODS: A decision analytic model was performed considering the correct diagnoses of CD and complications such as fistulas and abscesses as effects. Costs were estimated in Euro([symbol: see text]) using German fee schedules. RESULTS: MRI was more effective and more costly compared with enteroclysis. Incremental cost-effectiveness of MRI versus enteroclysis was [symbol: see text]1,595 per additional correctly diagnosed patient. CONCLUSIONS: The use of MRI in the work-up of patients with CD cannot be generally recommended from an economical perspective, but results of sensitivity analysis suggest that in patients with high prevalence of complications, MRI becomes as cost-effective as enteroclysis, which is accepted standard diagnostic imaging.     

Die Ausnutzung von Formaldehyd im Stoffwechsel der Erythrocyten von Neugeborenen,Erwachsenen und hypochrom-Anämischen Kleinkindern

Zusammenfassung Die vonMatthies an Kaninchenerythrocyten entdeckte Ausnutzung von Formaldehyd zur fermentativen Reduktion von Methämoglobin (Hb^III) in roten Zellen wird an Erythrocyten menschlicher Neugeborener und Erwachsener bestätigt. Bei einer Formaldehydkonzentration von 5·10^–3 mol geht die Hb^III-Reduktion rascher vor sich als mit Glucose.Neugeborenen-Erythrocyten verhalten sich qualitativ wie die Erythrocyten von Erwachsenen. Quantitativ besteht eine Minderleistung, wie schon aus Untersuchungen mit Glucose und Lactat geläufig ist.In hypochromen Erythrocyten ist die Hb^III-Rückbildung durch Formaldehyd wie die durch Glucose oder Lactat stark gesteigert. Die Steigerung geht weit über das hinaus, was aus der verringerten Hb-Beladung der Zellen erwartet werden könnte. Es wird auf die merkwürdige Tatsache aufmerksam gemacht, daß die überschießende Fermentaktivität in hypochromen Erythrocyten nur bei Prozessen gefunden wird, die mit einer Wasserstoffübertragung unter Vermittlung von Codehydrogenase I (DPN) verknüpft sind. Über Codehydrogenase II (TPN) ablaufende Prozesse zeigen diese Steigerung nicht.Mit Unterstützung durch die Deutsche Forschungsgemeinschaft.     

Influence of 2,3-diphosphoglycerate on the rate of oxidation of hemoglobin to methemoglobin

Summary 2,3-diphosphoglycerate, favoring the deoxyconfiguration of the hemoglobin molecule, accelerates the oxidation of hemoglobin to methemoglobin by potassiumferricyanide both in hemolysates from adult and cord blood. Hemoglobin oxidation is less enhanced in cord blood hemolysates.Supported by Deutsche Forschungsgemeinschaft (SFB 51). B.U. will present extended data to the Medical Faculty, University of Munich, as doctoral thesis.