[Urothelium cancer with trophoblastic differentiation. An unusual case of a 77 year old patient]. / Das Urothelkarzinom mit trophoblastischer Differenzierung. Eine seltene Tumorvariante am Beispiel einer 77-jährigen Patientin.

Urothelium carcinomas with beta HCG positive markers are a rarity in tumour differentiation. Syncytiotrophoblastic and, in a few cases, cytotrophoblastic giant cells are typical for this carcinoma. Such differentiation has an intensified potential for invasiveness and is accompanied by increased angiogenesis. In the present case, the mixture of trophoblastic cells indicates a common stem cell. In comparison with beta HCG negative transitional cell carcinoma, the prognosis is bad for beta HCG positive carcinoma. For this reason, a radical operation should be taken into consideration as early as possible.

[Radiation dose to the finger during injection of short-lived radionucleids in nuclear medicine (author's transl)]. / Zur Strahlenbelastung der Finger bei der Injektion kurzlebiger Radionuklide in der Nuklearmedizin.

The increasing use of short-lived radionucleids has shifted much of the radiation from the patient to the personnel. The purpose of this investigation, therefore, was to ascertain the greatest possible radiation dose to the fingers during injection of short-lived radionucleids. Basis for radiation measurements were small ionisation chambers attached to plastic syringes filled with radio-active material. By examples of typical situations, it was shown that the legally permissable values for partial body exposure may be exceeded. The necessity for using screening of the syringes is stressed. A simple method for making screening cylinders out of Wood's metal is described.

[A modified method for labeling erythrocytes with 99mTc (author's transl)]. / Ein modifiziertes Verfahren zur 99mTc-Markierung von Erythrozyten

A modified method for labeling erythrocytes with 99mTc-sodium pertechnetate for spleenic scintigraphy is described. In vitro investigations have shown that by omitting the customary process of washing and by simultaneous alteration of the erythrocytes during the tin incubation period, the duration of erythrocyte labeling can be considerably reduced. A yield of 96 of 98% can be achieved. The effect of the tin on the erythrocytes is further investigated. The effect of the incubation period and temperature, of the plasma in the erythrocyte suspension, of stirring and agitation, of the dispersion liquid and tin concentration were studied. The method proves satisfactory in 56 controlled spleenic scintigrams.

[Application of ROC analysis to evaluating different methods of skeletal scintigraphy. Description of a practicable method]. / Anwendung der ROC-Analyse zur Bewertung unterschiedlicher Verfahren zur Skelettszintigraphie. Vorstellung einer praktikablen Methode.

Various techniques producing similar information can be compared by the use of ROC analysis. A practical and quick method of ROC analysis, which is otherwise very time-consuming, has been described for comparing various types of skeletal scintigraphy. Data is obtained by means of a phantom and evaluated with the help of a scheme which requires only moderate computational facilities.

[Exposure technics for computed scintigrams]. / Untersuchungen zur Belichtungstechnik von Computerszintigrammen.

The technique of making copies on radiographic films or on multiformat cameras from computer scintigrams, computer tomograms, digital radiographs or other similar digital images should be carefully studied in order to make the best use of the characteristics of the film. Contrast transfer was studied using a nuclear medicine camera computer system with registration on radiographic film. Possible difficulties in obtaining copies and a simple software arrangement are described, which would influence contrast transmission.

[Questions of accuracy when using "not therapy-specific" computer systems for irradiation planning (author's transl)]. / Zu Fragen der Genauigkeit beim Einsatz "nichttherapiespezifischer" Computersysteme für die Bestrahlungsplanung.

The conditions were examined under which little and medium computer systems not having been primarily developed for radiotherapy can be used in order to make sufficiently precise calculations of dose distributions. The adapted accuracy of the principal factors influencing the dose distribution renders possible a time-saving calculation of several dose distributions and a final calculation. By comparison with a reference calculation made as accurately as possible, the isodose curve shows only little deviations. The following factors were examined in order to find out an eventual influence exerted upon an isodose displacement: number of scan points in the cross-section, correction of the oblique ray incidence, inhomogeneities, dissociations of the rotation field. To our opinion, the isodose displacements found for a dose calculation with adapted accuracy are acceptable when related to influencing factors depending on the individual patients.

[Quality assurance of brachytherapy by means of interactive computer-assisted planning of the dose distribution using visual optimization (author's transl)]. / Qualitätssicherung der Brachytherapie durch interaktive, computergestützte Planung der Dosisverteilung mit visueller Optimierung.

Not earlier than with present generation of afterloading apparatuses,--efficient, reliable and appropriate for many purposes,--it was possible in brachytherapy to give up the previous impractical application techniques. Brachytherapy thus has found the widespread use it merits because of its good results. Additional utilization of a computer for the planning of dose distributions will guarantee the quality possible now in brachytherapy. To that end, a method of computer-assisted planning is described. It can be used for different application techniques. Further improvement of the results obtained till now is discussed in detail.