Radiopeptide imaging is a valuable imaging method in the management of patients with neuroendocrine tumours (NET). To determine the clinical performance of gastrin receptor scintigraphy (GRS), it was compared with somatostatin receptor scintigraphy (SRS), computed tomography (CT) and 18F-FDG positron emission tomography (PET) in patients with metastasised/recurrent medullary thyroid carcinoma (MTC).

PURPOSE:To develop a manually movable laser system connected to the CT table for alignment of the isocenter cross of irradiation fields on the patient's skin directly after CT software simulation.MATERIAL AND METHODS:The specially designed laser system was constructed in the authors' department, and the mean focusing accuracy of isocenter translations was analyzed using Alderson phantom measurements. The mean overall accuracy from setup to treatment of the whole procedure of CT software simulation was measured by the comparison of bone structures and mamma contour of the digitally reconstructed radiograph (DRR) with the verification film. The time taken for the different setup procedure steps was evaluated for 70 breast cancer patients who were treated using tangential fields.RESULTS:The mean focusing accuracy of the manually movable laser system after defined isocenter translation was measured as 0.8 +/- 0.5 mm, the mean patient movement on the CT table as 2.0 +/- 1 mm, and the mean positioning accuracy of the first treatment after patient positioning corresponding to the skin alignments as 3.9 +/- 1.5 mm. The time periods for the different steps of the CT software simulation were measured, and the total duration was found to be 35.8 +/- 3.3 min.CONCLUSION:In general, the main advantage of well-known CT software simulation when compared to conventional simulation is the relief of the real X-ray simulator which is feasible with fast planning software (EXOMIO) and the presented movable laser system.

Background: The importance of the size of the primary tumor in Lymphomas and its size after treatment is still uncertain. Assuming a prognostic relevance, an assessment of tumor volume before and after induction of chemotherapy has been performed in the pediatric Hodgkin's disease study (HD-90). Since an exact CT-scan-based volumetric tumor assessment is time-consuming and in some centers not possible, the tumor volume is often estimated based on simple geometric approximations. Aim of this study was the development of an easy to apply and nearly exact model of volume estimation compared to CT-scan-based tumor volume measurements. Material and Methods: Shirty computed tomographies (CT) of mediastinal Hodgkin Lymphomas of children aged 5 to 16 years have been examined. The CT scans were digitalized using a CCD camera combined with a frame grabber, Applying the Global Lab image software, the true tumor volume was determined excluding Local organs, which did not belong to the Lymphoma. Subsequently, volumes were assessed using simple geometric models (block, ellipsoid, octaeder) by using the maximum diameters of the tumor. The differences between the volume of the geometric models and the true volume, based on the CT scan evaluation, were compared.

Ziel dieser Arbeit waren die Bestimmung eines möglichst exakten Modells zur Abschätzung der Volumina von Lymphommanifestationen im Vergleich zu computertomographisch bestimmten Tumorvolumina und eine Abschätzung der zu erwartenden Fehlerbreite.

Beurteilung der Bildqualität und Detailerkennbarkeit digitalisierter und nachbearbeiteter Feldkontrollaufnahmen am Computermonitor im Vergleich zum bisherigen Standard, der Beurteilung konventioneller Feldkontrollaufnahmen am Röntgenschaukasten.

PURPOSE Judgement of image quality and detail recognition of digitized and post-processed portal films presented on a computer monitor compared to the present standard, conventional portal films presented on a light box. MATERIALS AND METHODS Conventional portal films of 3 different tumor sites (10 pelvis, 10 cranium, 10 vertebral column) were presented to a panel of 8 observers in 3 different matters: conventional film presented on a light box (Conv), digitized post-processed images (Dig-1) and digitized post-processed images (Dig-2) presented on a high resolution computer monitor. Subjective judgement of image quality, detailed recognition and time requirement of conventional films compared to monitor presentation were evaluated using a 5-scaled questionnaire (from 1 = much better to 5 = much worse). Furthermore the observers had to point out predefined anatomical bony structure on the conventional films (Conv) as well as on the digitized post-processed images (Dig-2). Standard deviations of the landmark outlined by 10 different observers were used as a criterion of objective detail recognition (Figure 1). RESULTS Image quality of digitized post-processed images presented on the computer monitor was judged statistical significant better than that of conventional films (pelvis 78%, vertebral column 62%, cranium 45% better) (Figure 3). Similar results were found for comparison of detail recognition: digitized post-processed images were scored better for pelvis in 81%, for vertebral column in 57%, for cranium in 40% (Figure 4, Table 1). Most benefit from portal film enhancement was found for pelvic images, where portal films are known to be of poor image quality (Figure 2). In contrast image quality of non-processed digital images compared to conventional films was graded worse (pelvis 69%, vertebral column 53%, cranium 71% worse) (Figure 4). Digital post-processed images were especially for the pelvis judged to require less time (pelvis 68%, vertebral column 26%, cranium 8% less time requirement) (figure 5). For the pelvis a statistical significant decrease of standard deviations was found for Dig-2 compared to conventional films, indicating an objective increase of image quality and detailed recognition (Table 2). In case of vertebral column and cranium no significant differences were evaluated (Table 3). CONCLUSIONS Digitized enhanced portal films presented on a computer monitor resulted in a quicker assessment and equal to better image quality as well as detail recognition compared to conventional films. Non-processed digitized images were judged to be of less image quality.