Reducing aggressive intergroup action tendencies: effects of intergroup contact via perceived intergroup threat.

Two studies tested the prediction that more positive intergroup contact would be associated with reduced aggressive intergroup action tendencies, an effect predicted to occur indirectly via reduced intergroup threat perceptions, and over and above well-established effects of contact on intergroup attitudes. Study 1, using data based on a cross-section of the general population of eight European countries (France, Germany, Hungary, Italy, the Netherlands, Poland, Portugal, and the UK; N = 7,042), examined this hypothesis in the context of aggressive action tendencies towards immigrants. Study 2, using longitudinal data obtained from a general population sample in Northern Ireland, considered effects on aggressive action tendencies between ethno-religious groups in conflict. Both studies confirmed our predictions, showing that while perceived threat was associated with greater intergroup aggressive tendencies, positive intergroup contact was indirectly associated with reduced aggressive action tendencies, via reduced intergroup threat. Findings are discussed in terms of the theoretical contributions of this research for understanding the relationship between intergroup contact and intergroup aggression.

Inverse gender gap in Germany: social dominance orientation among men and women.

Across cultures studies show that men score higher on social dominance orientation than women. This gender gap is considered invariant, but conflicting explanations are discussed: Some authors refer to evolutionary psychology and perceive the gender gap to be driven by sociobiological factors. Other authors argue that social roles or gender-stereotypical self-construals encouraged by intergroup comparisons are responsible for attitudinal gender difference. In Study 1 we analyzed sex differences in social dominance orientation in three German probability surveys (each n > 2300). Unexpectedly, the analyses yielded an inverse gender gap with higher values for social dominance orientation in women than in men. Interactions with age, education, political conservatism, and perceived inequity indicated that the inverse gender gap can be mainly attributed to older, conservative, (and less educated) respondents, and those who feel they get their deserved share. In Study 2 we replicated the well-known gender gap with men scoring higher than women in social dominance orientation among German students. Results are interpreted on the basis of biocultural interaction, which integrates the sociobiological, social role, and self-construal perspectives. Our unusual findings seem to reflect a struggle for status by members of low-status groups who consider group-based hierarchy the most promising option to improve their status. While younger women take advantage of a relational, feminine self-construal that leads to lower social dominance orientation in young women than in young men, older women are supposed to profit from an agentic self-construal that results in stronger social dominance orientation values. Specific characteristics of the culture in Germany seem to promote this strategy. Here, we discuss the female ideal of the national socialist period and the agentic female social role in the post-war era necessitated by the absence of men.

Multiple breath-hold CBCT for online image guided radiotherapy of lung tumors: simulation with a dynamic phantom and first patient data.

BACKGROUND AND PURPOSE: Computer controlled breath-hold effectively reduces organ motion for image-guided precision radiotherapy of lung tumors. However, the acquisition time of 3D cone-beam-CT (CBCT) exceeds maximum breath-hold times. We have developed an approach enabling online verification using CBCT image acquisition with ABC®-based breath-hold. METHODS: Patient CBCT images were acquired with ABC®-based repeat breath-hold. The clinical situation was also simulated with a Motion Phantom. Reconstruction of patient and phantom images with selection of free-breathing and breath-hold projections only was performed. RESULTS: CBCT-imaging in repeat breath-hold resulted in a precisely spherical appearance of a tumor-mimicking structure in the phantom. A faint "ghost" structure (free-breathing phases) can be clearly discriminated. Mean percentage of patient breath-hold time was 66%. Reconstruction based on free-breathing-only shows blurring of both tumor and diaphragm, reconstruction based on breath-hold projections only resulted in sharp contours of the same structures. From the phantom experiments, a maximal repositioning error of 1mm in each direction can be estimated. DISCUSSION AND CONCLUSION: CBCT during repetitive breath hold provides reliable soft-tissue-based positioning. Fast 3D-imaging during one breath-hold is currently under development and has the potential to accelerate clinical linac-based volume imaging.

Accuracy of ultrasound-based image guidance for daily positioning of the upper abdomen: an online comparison with cone beam CT.

PURPOSE: Image-guided intensity-modulated radiotherapy can improve protection of organs at risk when large abdominal target volumes are irradiated. We estimated the daily positioning accuracy of ultrasound-based image guidance for abdominal target volumes by a direct comparison of daily imaging obtained with cone beam computed tomography (CBCT). METHODS AND MATERIALS: Daily positioning (n = 83 positionings) of 15 patients was completed by using ultrasound guidance after an initial CBCT was obtained. Residual error after ultrasound was estimated by comparison with a second CBCT. Ultrasound image quality was visually rated using a scale of 1 to 4. RESULTS: Of 15 patients, 7 patients had good sonographic imaging quality, 5 patients had satisfactory sonographic quality, and 3 patients were excluded because of unsatisfactory sonographic quality. When image quality was good, residual errors after ultrasound were -0.1 +/- 3.11 mm in the x direction (left-right; group systematic error M = -0.09 mm; standard deviation [SD] of systematic error, Sigma = 1.37 mm; SD of the random error, sigma = 2.99 mm), 0.93 +/- 4.31 mm in the y direction (superior-inferior, M = 1.12 mm; Sigma = 2.96 mm; sigma = 3.39 mm), and 0.71 +/- 3.15 mm in the z direction (anteroposterior; M = 1.01 mm; Sigma = 2.46 mm; sigma = 2.24 mm). For patients with satisfactory image quality, residual error after ultrasound was -0.6 +/- 5.26 mm in the x (M = 0.07 mm; Sigma = 5.67 mm; sigma = 4.86 mm), 1.76 +/- 4.92 mm in the y (M = 3.54 mm; Sigma = 4.1 mm; sigma = 5.29 mm), and 1.19 +/- 4.75 mm in the z (M = 0.82 mm; Sigma = 2.86 mm; sigma = 3.05 mm) directions. CONCLUSIONS: In patients from whom good sonographic image quality could be obtained, ultrasound improved daily positioning accuracy. In the case of satisfactory image quality, ultrasound guidance improved accuracy compared to that of skin marks only minimally. If sonographic image quality was unsatisfactory, daily CBCT scanning improved treatment accuracy distinctly over that of ultrasound. Use of daily ultrasound or CBCT imaging can help to reduce PTV margins and protect organs at risk compared to the use of skin mark-based positioning.

[Patient-centered image and data management in radiation oncology]. / Patientenbezogenes Bild- und Datenmanagement in der Radioonkologie.

BACKGROUND: : Recent changes in the radiotherapy (RT) workflow through the introduction of complex treatment paradigms such as intensity-modulated radiotherapy (IMRT) and, recently, image-guided radiotherapy (IGRT) with their increase in data traffic for different data classes have mandated efforts to further integrate electronic data management for RT departments in a patient- and treatment-course-centered fashion. METHODS: : Workflow in an RT department is multidimensional and multidirectional and consists of at least five different data classes (RT/machine data, patient-related documents such as reports and letters, progress notes, DICOM [Digital Imaging and Communications in Medicine] image data, and non-DICOM image data). Data has to be handled in the framework of adaptive feedback loops with increasing frequency. This is in contrast to a radiology department where mainly DICOM image data and reports have to be widely accessible but are dealt with in a mainly unidirectional manner. When compared to a diagnostic Radiology Information System (RIS)/Picture Archiving and Communication System (PACS), additional legal requirements have to be conformed to when an integrated electronic RT data management system is installed. Among these are extended storage periods, documentation of treatment plan approval by physicians and physicist, documentation of informed consent, etc. CONCLUSION: : Since the transition to a paper- and filmless environment in medicine and especially in radiation oncology is unavoidable, this review discusses these issues and suggests a possible hardware and organizational architecture of an RT department information system under control of a Hospital Information System (HIS), based on combined features of genuine RT Record and Verify (R&V) Systems, PACS, and Electronic Medical Records (EMR).

Phantom measurements to quantify the accuracy of a commercially available cone-beam CT gray-value matching algorithm using multiple Fiducials.

PURPOSE: : To assess the accuracy of the gray-value matching algorithm (XVI, Elekta) when multiple iodine-125 ((125)I) seeds are used as fiducials. MATERIAL AND METHODS: : A phantom, consisting of a plastic box filled with water-dense material containing about 50 dummy seeds, developed primarily as a manual-skill trainer for (125)I seed implantation was used (Figure 1). The phantom was scanned first with a planning CT (PCT) at a slice thickness of 1 mm, 3 mm and 5 mm and with cone-beam CT (CBCT) to be associated with each reference PCT. Matching was performed with the XVI gray-value algorithm. The isocenter was marked with external markers at PCT. After matching, residual error was determined as the difference between planned isocenter and the isocenter that would have been treated based on the matching process. The procedure was performed twice, once without any manipulation (Figure 2) and once with deformation of the seed-bearing dummy prostate by inserting a plug into the phantom aperture that mimics the rectum (Figure 3). RESULTS: : For the undeformed phantom the maximal residual error regarding the isocenter after gray-value matching around the seed-bearing region was 0.0 mm in x, y and z directions in case of the PCT with 1 mm thickness. The range of residual error was 0-0.4 mm in case of the PCT with 3 mm and 0-0.8 mm in x, y and z directions in case of 5 mm slice thickness, respectively (Figure 4). For the deformed phantom similar results were obtained (maximum error: 1.1 mm). CONCLUSION: : The residual error after seed-based matching regarding the phantom isocenter was < 1.1 mm in all cases and for the clinical situation (3 mm slice thickness) always < 0.4 mm. The algorithm is therefore appropriate for precision radiotherapy.

Intrafraction motion of the prostate during an IMRT session: a fiducial-based 3D measurement with Cone-beam CT.

BACKGROUND: Image-guidance systems allow accurate interfractional repositioning of IMRT treatments, however, these may require up to 15 minutes. Therefore intrafraction motion might have an impact on treatment precision. 3D geometric data regarding intrafraction prostate motion are rare; we therefore assessed its magnitude with pre- and post-treatment fiducial-based imaging with cone-beam-CT (CBCT). METHODS: 39 IMRT fractions in 5 prostate cancer patients after 125I-seed implantation were evaluated. Patient position was corrected based on the 125I-seeds after pre-treatment CBCT. Immediately after treatment delivery, a second CBCT was performed. Differences in bone- and fiducial position were measured by seed-based grey-value matching. RESULTS: Fraction time was 13.6 +/- 1.6 minutes. Median overall displacement vector length of 125I-seeds was 3 mm (M = 3 mm, Sigma = 0.9 mm, sigma = 1.7 mm; M: group systematic error, Sigma: SD of systematic error, sigma: SD of random error). Median displacement vector of bony structures was 1.84 mm (M = 2.9 mm, Sigma = 1 mm, sigma = 3.2 mm). Median displacement vector length of the prostate relative to bony structures was 1.9 mm (M = 3 mm, Sigma = 1.3 mm, sigma = 2.6 mm). CONCLUSION: a) Overall displacement vector length during an IMRT session is < 3 mm.b) Positioning devices reducing intrafraction bony displacements can further reduce overall intrafraction motion.c) Intrafraction prostate motion relative to bony structures is < 2 mm and may be further reduced by institutional protocols and reduction of IMRT duration.

Accuracy of ultrasound-based (BAT) prostate-repositioning: a three-dimensional on-line fiducial-based assessment with cone-beam computed tomography.

PURPOSE: To assess the accuracy of ultrasound-based repositioning (BAT) before prostate radiation with fiducial-based three-dimensional matching with cone-beam computed tomography (CBCT). PATIENTS AND METHODS: Fifty-four positionings in 8 patients with 125I seeds/intraprostatic calcifications as fiducials were evaluated. Patients were initially positioned according to skin marks and after this according to bony structures based on CBCT. Prostate position correction was then performed with BAT. Residual error after repositioning based on skin marks, bony anatomy, and BAT was estimated by a second CBCT based on user-independent automatic fiducial registration. RESULTS: Overall mean value (MV+/-SD) residual error after BAT based on fiducial registration by CBCT was 0.7+/-1.7 mm in x (group systematic error [M]=0.5 mm; SD of systematic error [Sigma]=0.8 mm; SD of random error [sigma]=1.4 mm), 0.9+/-3.3 mm in y (M=0.5 mm, Sigma=2.2 mm, sigma=2.8 mm), and -1.7+/-3.4 mm in z (M=-1.7 mm, Sigma=2.3 mm, sigma=3.0 mm) directions, whereas residual error relative to positioning based on skin marks was 2.1+/-4.6 mm in x (M=2.6 mm, Sigma=3.3 mm, sigma=3.9 mm), -4.8+/-8.5 mm in y (M=-4.4 mm, Sigma=3.7 mm, sigma=6.7 mm), and -5.2+/-3.6 mm in z (M=-4.8 mm, Sigma=1.7 mm, sigma=3.5 mm) directions and relative to positioning based on bony anatomy was 0+/-1.8 mm in x (M=0.2 mm, Sigma=0.9 mm, sigma=1.1 mm), -3.5+/-6.8 mm in y (M=-3.0 mm, Sigma=1.8 mm, sigma=3.7 mm), and -1.9+/-5.2 mm in z (M=-2.0 mm, Sigma=1.3 mm, sigma=4.0 mm) directions. CONCLUSIONS: BAT improved the daily repositioning accuracy over skin marks or even bony anatomy. The results obtained with BAT are within the precision of extracranial stereotactic procedures and represent values that can be achieved with several users with different education levels. If sonographic visibility is insufficient, CBCT or kV/MV portal imaging with implanted fiducials are recommended.

[The use of guidelines in the primary care management of hypertension and diabetes]. / Leitlinienorientierung deutscher Hausärzte bei der Diagnostik und Therapie der arteriellen Hypertonie und des Diabetes mellitus.

OBJECTIVES: The paper examines to what degree German primary care physicians know and work along the rules established in guidelines for arterial hypertension and diabetes mellitus. METHODS: HYDRA is a 2-stage cross-sectional point prevalence study with 1912 participating primary care settings throughout Germany including 45,125 patients. A pre-study questionnaire to assess doctors practice patterns was used. Subsequently doctors completed a structured clinical appraisal with a diagnostic workup and characterization of the current treatments provided. All patients filled out a questionnaire. RESULTS: Pre-study results show that only every second primary care physician manages the patients according to established guidelines. Further, physicians estimated their own work as problematic and not always successful. Guideline-oriented doctors were more likely to report hypertension and diabetes treatment patterns that also match guideline's recommendations. CONCLUSIONS: The study shows a considerable degree of dissatisfaction with the quality of their work among primary care physicians. Guideline-oriented doctors however reveal more frequently formally adequate management characteristics. This encouraging aspect suggests the need of more successful implementation of medical guidelines in order to achieve improved evidence-based medicine and better patient-oriented health care.

HYDRA: possible determinants of unsatisfactory hypertension control in German primary care patients.

The Hypertension and Diabetes Screening and Awareness (HYDRA) study is a cross-sectional point-prevalence study performed in September 2001; 45,125 primary care attendees were recruited from a representative nationwide sample of 1912 primary care practices in Germany. Around 42% of all patients presenting in these practices had hypertension (WHO definition). In approximately 70% of these patients, hypertension was diagnosed by doctors and 84% of diagnosed patients were on antihypertensive medication, but in less than 30% of treated patients was blood pressure controlled (< 140/90 mmHg). The control rate in all patients presenting with hypertension (including those patients unrecognized) was as low as 19%. The present analysis aimed to find explanations for this unsatisfactory outcome of hypertension control. The main finding was that the rate of diagnosis of hypertension is alarmingly low in young people, probably due to insufficient blood pressure screenings. The data further indicated that doctors still set their target of treatment according to outdated guidelines and that doctors still orientate their treatment primarily with regard to the diastolic pressure. These insights into the causes of unsatisfactory hypertension control may help to direct future educational programmes designed to improve hypertension management specifically to these deficits and thereby to improve control rates.