[Protection of eye lens in computed tomography--dose evaluation on an anthropomorphic phantom using thermo-luminescent dosimeters and Monte-Carlo simulations]

PURPOSE

The lens of an eye is a particularly radiosensitive organ. This study investigates two different materials for eye shielding during CT scanning, i. e. a commercially available bismuth protector and a newly developed material for eye shielding, comprised of an alloy of Bi/Sb/Gd/W.

MATERIALS AND METHODS

The radiation dose during head CT scanning was measured using thermoluminescence dosimeters and an anthropomorphic Alderson-RANDO phantom. A radiation dose reduction was compared to two shielding materials and to the condition without any eye shielding. The effect of gantry angulation that excludes the eyes from beam path was also investigated. Radiation dose measurements were validated using a Monte-Carlo simulation. For this simulation we used the EGSsnr code system, and a new application CTDOSPP was developed for simulation of the computed tomography examination. Eight radiologists evaluated the diagnostic quality of the images.

RESULTS

Dose measurements and Monte-Carlo simulations are in good agreement. If the eye shields are placed in the primary beam path, bismuth eye shielding and the new material reduce the dose by up to 38 % and 48 %, respectively. Angling the gantry causes an 88 % reduction in radiation dose. All shielding materials generate beam hardening artifacts located close to the protector, but the artifacts do not spread into the brain.

CONCLUSION

The application of eye shields during CT examination of a head causes a significant reduction in radiation dose. The new protector material shows a significantly higher dose reduction in contrast to the commercially available bismuth shield. The best protection from radiation dose can be attained using gantry angulation.

B-type natriuretic peptide and wall stress in dilated human heart

Background Although B-type natriuretic peptide (BNP) is used as complimentary diagnostic tool in patients with unknown thoracic disorders, many other factors appear to trigger its release. In particular, it remains unresolved to what extent cellular stretch or wall stress of the whole heart contributes to enhanced serum BNP concentration. Wall stress cannot be determined directly, but has to be calculated from wall volume, cavity volume and intraventricular pressure of the heart. The hypothesis was, therefore, addressed that wall stress as determined by cardiac magnetic resonance imaging (CMR) is the major determinant of serum BNP in patients with a varying degree of left ventricular dilatation or dysfunction (LVD). Methods A thick-walled sphere model based on volumetric analysis of the LV using CMR was compared with an echocardiography-based approach to calculate LV wall stress in 39 patients with LVD and 21 controls. Serum BNP was used as in vivo marker of a putatively raised wall stress. Nomograms of isostress lines were established to assess the extent of load reduction that is necessary to restore normal wall stress and related biochemical events. Results Both enddiastolic and endsystolic LV wall stress were correlated with the enddiastolic LV volume (r = 0.54, P < 0.001; r = 0.81, P < 0.001). LV enddiastolic wall stress was related to pulmonary pressure (capillary: r = 0.69, P < 0.001; artery: r = 0.67, P < 0.001). Although LV growth was correlated with the enddiastolic and endsystolic volume (r = 0.73, P < 0.001; r = 0.70, P < 0.001), patients with LVD exhibited increased LV wall stress indicating an inadequately enhanced LV growth. Both enddiastolic (P < 0.05) and endsystolic (P < 0.01) wall stress were increased in patients with increased BNP. In turn, BNP concentration was elevated in individuals with increased enddiastolic wall stress (>8 kPa: 587 +/- 648 pg/ml, P < 0.05; >12 kPa: 715 +/- 661 pg/ml, P < 0.001; normal < or =4 kPa: 124 +/- 203 pg/ml). Analysis of variance revealed LV enddiastolic wall stress as the only independent hemodynamic parameter influencing BNP (P < 0.01). Using nomograms with "isostress" curves, the extent of load reduction required for restoring normal LV wall stress was assessed. Compared with the CMR-based volumetric analysis for wall stress calculation, the echocardiography based approach underestimated LV wall stress particularly of dilated hearts. Conclusions In patients with LVD, serum BNP was increased over the whole range of stress values which were the only hemodynamic predictors. Cellular stretch appears to be a major trigger for BNP release. Biochemical mechanisms need to be explored which appear to operate over this wide range of wall stress values. It is concluded that the diagnostic use of BNP should primarily be directed to assess ventricular wall stress rather than the extent of functional ventricular impairment in LVD.

Natural course of small adrenal lesions in multiple endocrine neoplasia type 1: an endoscopic ultrasound imaging study

OBJECTIVE

Adrenal lesion is one of the features of multiple endocrine neoplasia type 1 (MEN1). This study aimed to assess prevalence, natural course and clinical relevance of small adrenal lesions without clinical symptoms, endocrine activity, or mechanical problems and thus without clear indication for surgical therapy by endoscopic ultrasound (EUS).

DESIGN AND METHODS

Forty-nine patients with familial MEN1 were studied. Twenty-seven of these with adrenal lesions were detected by EUS and at least two performed EUS examinations were included into a subgroup where changes in adrenal morphology were studied by measuring changes in the largest diameter of the dominant adrenal tumour.

RESULTS

EUS detected adrenal lesions in 36 (73%) patients: 6 (12%) plump adrenals, 17 (35%) nodular hyperplasia, 12 (24%) adenomas and 1 (2%) cyst. Bilateral adrenal lesions were detected in 17 patients and unilateral in 19 patients. A change in the largest tumour diameter was found to be for nodular hyperplasia -0.02+/-1.41% per month (range -2.56 to 4.58%) and for adenomas -0.61+/-1.95% per month (range -6.25 to 1.15%). One patient had an adrenal cyst with significant growth. There was no evidence of carcinoma or metastatic disease during the study.

CONCLUSIONS

The prevalence of adrenal lesions in MEN1 is higher than that reported earlier. Except one cystic lesion, no significant change in the tumour size was observed over a mean observation period of more than 2 years. In a typical situation, small adrenal lesions in MEN1 seem to be constant in their morphology.

Localisation and staging of gastrin producing tumours using cross-sectional imaging modalities

Cross sectional imaging in the assessment of gastrinomas has three major applications: Tumor localization (sporadic gastrinoma, MEN I) in patients undergoing primary or secondary surgery. Staging of metastasized tumors, especially assessment of lymph nodes and liver metastases, possibly including a risk analysis prior to liver resection. Post-surgery follow-up and monitoring of bio- or chemotherapy. Detection of primary tumors is strongly correlated with their size. However, the sensitivity of surgical assessment of the mostly small tumors by experienced surgeons is much higher than that of any imaging modality. Of all imaging modalities, endoultrasonography (EUS) followed by Somatostatin receptor scintigraphy (SRS) is the most sensitive modality for the assessment of pancreatic tumors in asymptomatic patients suffering from a MEN-I syndrome. Scintigraphy has the highest sensitivity in tumors of symptomatic patients and in the assessment of metastases. CT and MRI are only second line diagnostic modalities. Their sensitivity is largely dependent on the selection of patients. As a potential application, 3D reconstruction of nearly isotropic CT data sets for the risk assessment prior to liver resection is currently developing. Due to the absent radiation exposure, MRI is increasingly utilized to monitor the response of metastases under systemic therapy, e.g. in clinical trials.

Relation of B-type natriuretic peptide to left ventricular wall stress as assessed by cardiac magnetic resonance imaging in patients with dilated cardiomyopathy

Ventricular loading conditions are crucial determinants of cardiac function and prognosis in heart failure. B-type natriuretic peptide (BNP) is mainly stored in the ventricular myocardium and is released in response to an increased ventricular filling pressure. We examined, therefore, the hypothesis that BNP serum concentrations are related to ventricular wall stress. Cardiac magnetic resonance imaging (MRI) was used to assess left ventricular (LV) mass and cardiac function of 29 patients with dilated cardiomyopathy and 5 controls. Left ventricular wall stress was calculated by using a thick-walled sphere model, and BNP was assessed by immunoassay. LV mass (r = 0.73, p < 0.001) and both LV end-diastolic (r = 0.54, p = 0.001) and end-systolic wall stress (r = 0.66, p < 0.001) were positively correlated with end-diastolic volume. LV end-systolic wall stress was negatively related to LV ejection fraction (EF), whereas end-diastolic wall stress was not related to LVEF. BNP concentration correlated positively with LV end-diastolic wall stress (r = 0.50, p = 0.002). Analysis of variance revealed LV end-diastolic wall stress as the only independent hemodynamic parameter influencing BNP (p < 0.001). The present approach using a thick-walled sphere model permits determination of mechanical wall stress in a clinical routine setting using standard cardiac MRI protocols. A correlation of BNP concentration with calculated LV stress was observed in vivo. Measurement of BNP seems to be sufficient to assess cardiac loading conditions. Other relations of BNP with various hemodynamic parameters (e.g., EF) appear to be secondary. Since an increased wall stress is associated with cardiac dilatation, early diagnosis and treatment could potentially prevent worsening of the outcome.

A new methodological approach to assess cardiac work by pressure-volume and stress-length relations in patients with aortic valve stenosis and dilated cardiomyopathy

In experimental animals, cardiac work is derived from pressure-volume area and analyzed further using stress-length relations. Lack of methods for determining accurately myocardial mass has until now prevented the use of stress-length relations in patients. We hypothesized, therefore, that not only pressure-volume loops but also stress-length diagrams can be derived from cardiac volume and cardiac mass as assessed by cardiac magnetic resonance imaging (CMR) and invasively measured pressure. Left ventricular (LV) volume and myocardial mass were assessed in seven patients with aortic valve stenosis (AS), eight with dilated cardiomyopathy (DCM), and eight controls using electrocardiogram (ECG)-gated CMR. LV pressure was measured invasively. Pressure-volume curves were calculated based on ECG triggering. Stroke work was assessed as area within the pressure-volume loop. LV wall stress was calculated using a thick-wall sphere model. Similarly, stress-length loops were calculated to quantify stress-length-based work. Taking the LV geometry into account, the normalization with regard to ventricular circumference resulted in "myocardial work." Patients with AS (valve area 0.73+/-0.18 cm(2)) exhibited an increased LV myocardial mass when compared with controls (P<0.05). LV wall stress was increased in DCM but not in AS. Stroke work of AS was unchanged when compared with controls (0.539+/-0.272 vs 0.621+/-0.138 Nm, not significant), whereas DCM exhibited a significant depression (0.367+/-0.157 Nm, P<0.05). Myocardial work was significantly reduced in both AS and DCM when compared with controls (129.8+/-69.6, 200.6+/-80.1, 332.2+/-89.6 Nm/m(2), P<0.05), also after normalization (7.40+/-5.07, 6.27+/-3.20, 14.6+/-4.07 Nm/m(2), P<0.001). It is feasible to obtain LV pressure-volume and stress-length diagrams in patients based on the present novel methodological approach of using CMR and invasive pressure measurement. Myocardial work was reduced in patients with DCM and noteworthy also in AS, while stroke work was reduced in DCM only. Most likely, deterioration of myocardial work is crucial for the prognosis. It is suggested to include these basic physiological procedures in the clinical assessment of the pump function of the heart.

Effectiveness and renal tolerance of multidetector helical CT with gadobutrol: results of a comparative porcine study

PURPOSE

To prospectively evaluate the safety and effectiveness of high doses of 1 mol/L gadobutrol as a contrast agent for computed tomography (CT).

MATERIALS AND METHODS

Experiments were performed according to guidelines for care of laboratory animals. The local animal care committee approved the study protocol. Unenhanced and contrast material-enhanced CT images of the chest and abdomen were obtained randomly in nine domestic pigs. Gadobutrol was injected (1, 2, or 3 mL per kilogram of body weight; three pigs for each dose). Attenuation was measured in different vascular and parenchymal structures. Changes in blood chemistry and hematologic parameters were monitored before and 1, 2, 3, and 7 days after gadobutrol administration. Urine samples were evaluated before and 7 days after gadobutrol administration. Technetium 99m mertiatide renal scintigraphy was performed before and 7 days after contrast medium injection. Animals were sacrificed 7 days after contrast medium administration, and one kidney was removed from each animal for examination with light microscopy. No serious adverse events occurred. A mixed-model nested analysis of variance was used for statistical evaluation.

RESULTS

Mean attenuations for the 1, 2, and 3 mL/kg gadobutrol doses, respectively, were 148 HU +/- 20 (standard deviation), 282 HU +/- 18, and 289 HU +/- 20 in the thoracic aorta; 99 HU +/- 11, 166 HU +/- 9, and 153 HU +/- 18 in the kidneys; and 106 HU +/- 7, 186 HU +/- 18, and 224 HU +/- 24 in the inferior vena cava. No clinically relevant changes in hematologic, blood chemistry, or urine analysis results were detected. Markers for glomerular filtration and tubular function were unaffected in all groups. Scintigraphy revealed no differences between unenhanced and contrast-enhanced results. No morphologic changes of the renal parenchyma were found at histologic analysis.

CONCLUSION

Contrast-enhanced CT with a 2 or 3 mmol/kg dose of 1 mol/L gadobutrol resulted in excellent vascular and parenchymal enhancement. A gadobutrol dose of up to 3 mL/kg did not affect renal function.

Accuracy of single-session extracranial radiotherapy for simple shaped lung tumor or metastasis using fast 3-D CT treatment planning

BACKGROUND

This study is situated in the area of measuring set-up accuracy and time periods of single-session extracranial radiotherapy (SSRT) for simple-shaped targets (e.g., spherical or rotational symmetrical) definitively located in the peripheral lung.

METHODS AND MATERIALS

After adaptation of the stereotactic body frame, the patient has to remain in the vacuum pillow during planning computed tomography (CT), fast three-dimensional (3-D) treatment planning, and direct irradiation after verification. Fast preplanning is performed by using virtual simulation software to accelerate the method.

RESULTS

In our new procedure, SSRT is applied in approximately 1.5 h. The mean setup accuracy vector was 2.4+/-0.7 mm in the range of 1.34 to 4 mm. Mean intrafractional patient movement in the stereotactic body frame before and after radiation was 0.70 mm+/-0.5 mm and 0.76+/-0.76 mm in the range of 0 to 2.8 mm. Mean time period steps were measured at (1) planning CT with 3-D treatment planning: 76+/-12 min; (2) irradiation and verification: 33+/-7 min; and (3) complete procedure duration: 109+/-11 min (range, 89-169).

CONCLUSIONS

The main difference between the positioning technique of SSRT and that of conventional extracranial radiosurgery is the tighter patient fixation, which guarantees minimal patient movement. The main advantages are procedure acceleration and omission of CT simulation. SSRT is a preliminary stage of real-time treatment.

[Orthorad--the online reference database of skeletal plain film radiography]

PURPOSE

It is evident that there is a growing need for Internet-based reference databases for reasons of practicability and due to the increasing use of reporting on digital workstations. The main advantages of online databases are expected with respect to plain film radiography and cross-sectional imaging. A reference database of skeletal plain film radiography was to be created using the Orthorad program.

MATERIALS AND METHODS

The most important standard settings and special images of young and healthy adults in plain film radiography were collected over one year. All samples were approved for the Orthorad database by a board qualified radiologist. Based on the workflows of radiographers and radiologists, the records were organized by body part ( http://www.idr.med.uni-erlangen.de/orthorad/orthorad.htm ). This logical data structure will ensure that the tool serves as a source of information in two ways: On the one hand, the radiographer can access information on positioning, tube voltage and cassette format. On the other hand, the radiologist receives important knowledge regarding X-ray anatomy, reference data regarding the human skeleton, and information about the correct reporting for an image.

RESULTS AND CONCLUSION

Orthorad is used as an online reference database for traumatologic plain film radiography to support radiographers and radiologists in their daily working routines. To date, user feedback has been positive.

[KIS-RIS-PACS integration: the Marburg approach]

When describing the development of data processing at the Department of Radiology at the Philipps University of Marburg, three phases can be identified covering the areas of patient care, education, and research as well as administrative and organizational aspects. The first phase (1987-1995) was centered on radiology and characterized by the early implementation of the radiology information system (RIS) and installation of a picture archiving and communication system (PACS). The experiences gained during this phase led to intensive discussion on application-oriented information processing. The second phase (1996-2000) describes the changes in the general framework brought by Internet technology and international standards. The course was set for the future of data processing in the hospital setting. The phase ended with implementation of a clinical workplace system (KAS) as the basis for a comprehensive electronic patient record and the switch in radiology to an integrated RIS solution. The third phase (2001-2006) addressed further implementation and development of clinical data management in which both regular documentation of patient data and information processing not related to patients are optimized by making use of Intranet/Internet technology. It includes the hospital wide implementation of PACS and the forthcoming phase of information processing increasingly shaped by workflow and decision support.

Local administration of NF-kappa B decoy oligonucleotides to prevent restenosis after balloon angioplasty: an experimental study in New Zealand white rabbits

PURPOSE

To evaluate the efficacy of NF-kappa B oligonucleotides (ODN) administered by local administration with the channeled balloon catheter to prevent restenosis after balloon angioplasty in restenotic iliac arteries of New Zealand white rabbits.

MATERIALS AND METHODS

In vitro, 8000 rabbit vascular smooth muscle cells (rVSMC) where transfected with a liposomal carrier (TfX50) with 100 ng of decoy and scrambled ODN. Inhibition of proliferation was measured using a MTT assay after 24 hours in comparison to control. In vivo, 22 male New Zealand White rabbits were fed a 1% cholesterol diet and received denudation of both common iliac arteries with a 3 mm balloon catheter to induce an arterial stenosis. Four weeks after stenosis induction, local application of NF-kappa B in two different concentrations (1 mug: n = 14; 10 mug: n = 8) was performed randomly on one common iliac artery. Scrambled oligonucleotides without specific binding capacities were injected into the contralateral side. The channeled balloon catheter allows simultaneous balloon dilation (8 atm) of the stenosis and local application of a drug solution (2 atm). Four weeks after local drug delivery the animals were killed and the vessels were excised and computerized morphometric measurements were performed.

RESULTS

NF-kappa B decoy ODN but not scrambled ODN inhibited proliferation of rVSMC in vitro. Following local ODN application in the animals, no acute vascular complications were seen. NF-kappa B ODN resulted in a statistically non significant reduction of neointimal area compared to the control group. The neointimal area was 0.97 mm(2) using 1 mug NF-kappa B ODN compared to 0.98 mm(2) in the control group. The higher dose resulted in a neointimal area of 0.97 mm(2) compared to 1.07 mm(2) at the control side.

CONCLUSIONS

Local drug delivery of NF-kappa B ODN using the "channeled balloon" catheter could not reduce neointimal hyperplasia in stenostic rabbit iliac arteries. Application modalities have to be improved to enhance the effect of the local application to prevent restenosis after balloon angioplasty.

Integrated outcome assessment after anterior cervical discectomy and fusion: myelocompression but not adjacent instability affect patient-reported quality of life and cervical spine symptoms

STUDY DESIGN

The authors conducted a cross-sectional study.

OBJECTIVE

Integrated assessment of adjacent instability (AI), myelocompression (MC), magnetic resonance imaging (MRI) signs of myelopathy (MRISM), physician-assessed clinical signs and symptoms, including clinical signs of myelopathy (CSM), patients' self-reported symptoms and quality of life after anterior cervical discectomy and fusion (ACDF).

MATERIALS AND METHODS

Fifty-four patients who had ACDF between 1986 and 1995 received MRI scans, conventional and flexion/extension radiographs to assess myelocompression, MRISM, fusion, and AI. Clinical outcome was assessed using signs and symptoms based on selected items of Odom's criteria, Oswestry low back pain disability questionnaire, and the neck disability index. Patients reported their quality of life (QL) on a standardized instrument (Profiles of QL of Chronically Ill [PLC]) and by a specific validated Cervical Spine Symptom Scale (CSSS).

RESULTS

Myelocompression was found more frequently than expected (24%). MRISM were seen in 2 patients (4%). One of the 2 patients developed CSM. Fusion was achieved in 94% (with kyphosis in 17%). AI was found in 30%. However, only myelocompression but not AI was associated with statistically significant decreases in most QL scores (i.e., everyday capabilities, positive mood) and high cervical spine symptom burden (all P's < 0.05).

CONCLUSIONS

The study results underline the need for a better understanding of the biomechanical changes in the adjacent unfused segments. Consensus is needed on postoperative follow-up guidelines, including pain management strategies. Future studies on the outcome of ACDF will profit from an integrated outcome approach, including assessments based on imaging, physicians, and patients.

[Embolization of pulmonary arteriovenous malformations with electrolytically detachable coils in patients with hereditary hemorrhagic telangiectasia]

BACKGROUND

Pulmonary arteriovenous malformations (PAVM) can be found in approximately 20 % to 35 % of patients with hereditary hemorrhagic telangiectasia (HHT). PAVM should be treated since they are a source of paradoxical embolization, potentially resulting in severe neurologic complications. The treatment of choice is the endovascular embolization with coils.

PATIENTS AND METHODS

Seven patients with HHT underwent superselective embolization of PAVM detected during screening for PAVM. Four patients had a single PAVM and one patient 3, 4 and 5 PAVMs, respectively. Electrolytically detachable coils were used for embolization. In addition, coils with synthetic fibers were used during 6 embolizations for completion of embolization.

RESULTS

Embolization was technically successful in all patients. Complete primary occlusion was achieved in all PAVM. No coil migration or occlusion of unaffected pulmonary arteries was observed. After embolization, one patient developed a small pleural effusion, which was treated symptomatically.

CONCLUSION

As a minimally invasive procedure, superselective embolization is the treatment of choice in treating PAVM in patients with HHT. With the use of electrolytically detachable coils, the ideal coil size can be chosen and exact placement achieved without the risk of coil migration or occlusion of unaffected pulmonary arteries.

Evaluation of a laser system for CT software simulation (EXOMIO) in patients with breast cancer

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.

The effect of Palamed G bone cement on early migration of tibial components in total knee arthroplasty

OBJECTIVE

Migration of the tibial component in total knee arthroplasty (TKA) is subject of many studies using roentgen stereophotogrammetric analysis (RSA). In previous studies of cemented and uncemented tibial components, high migration values were found. Improvements in cementing technique, prosthetic design and pre-coating techniques reduced these values as shown in more recent studies.

MATERIAL AND SUBJECTS

A total of 35 patients were initially included in the study and operated on between 12/1999 and 10/2000. All patients received a NexGen TKA cemented into the proximal tibia using Palamed G bone cement. The implants and the tibial metaphysis were marked with standard tantalum markers. Radiostereometric analysis was performed post-operatively and after 3, 6 and 12 months using a standard digital radiostereometric analysis. Functional parameters were assessed using the Knee Society Score (KSS) clinical rating system.

RESULTS

There were no complications and failures within the first year. After 1 year radiostereometric measurements of the translational parameters along and the rotational parameters around the x-, y- and z-axis revealed: X-Trans -0.19 mm, Y-Trans +0.02 mm, Z-Trans +0.08 mm, X-Rot +0.26 degrees, Y-Rot -0.35 degrees, Z-Rot +0.09 degrees. The maximum total point motion was +0.96 mm and the mean maximum subsidence was -0.23 mm. Except for anterior-posterior, medio-lateral stability and extension leg all endpoints of the KSS clinical rating system showed a significant improvement.

CONCLUSIONS

After 12 months, the use of Palamed G bone cement in total knee arthroplasty was demonstrated to be safe. Both the clinical and radiostereometric results were good and comparable to the results reported in other RSA studies in cemented total knee arthroplasty.

Transarterial chemoembolization of advanced liver metastases of neuroendocrine tumors--a retrospective single-center analysis

BACKGROUND

In neuroendocrine tumors, metastases are a negative prognostic factor for survival and quality of life. Transcatheter arterial chemoembolization (TACE) is thought to be an effective symptomatic and antiproliferative treatment in patients with otherwise progressive disease.

METHODS

62 chemoembolization procedures in 26 patients with progressive neuroendocrine tumors were reviewed. The underlying disease was carcinoid syndrome in 10, non-functional midgut tumor in 2, non-functional pancreatic tumor in 7, malignant insulinoma in 2 patients, non-functional tumor of the stomach in 1 and of unknown origin in 4 patients. Tumor burden of the liver was <25% in 3, 25-50% in 11, 50-75% in 6 and >75% in 6 patients.

RESULTS

TACE was technically successful in 57 cases. Four patients developed minor and 5 major complications. The 30-day mortality rate was 7.7%. According to WHO criteria, 14 patients had no change in tumor burden, 2 had regression and 5 progress after chemoembolization. Patients with a tumor burden >75% of the liver did not benefit from TACE due to the development of major complications, whereas patients with low (<50%) tumor burden and high (>50%) lipiodol uptake showed a trend towards longer survival. Five-year survival time after diagnosis was 48%. Patients treated with octreotide and/or alpha-interferon had no benefit from chemoembolization with regard to their carcinoid syndrome.

CONCLUSIONS

In this retrospective study, patients with low (<50%) tumor burden and high (>50%) lipiodol uptake responded better to TACE than end-stage patients.

[From clinical guidelines to clinical pathways: development of a management-oriented algorithm for the treatment of polytraumatized patients in the acute period]

INTRODUCTION

The treatment of polytraumatized patients in the acute period is an exemplary model of multidisciplinary cooperation in a very critical timeframe. Implementing standards formulated in the clinical guidelines of the German Association of Traumatology requires a detailed description of "how to do it."

METHODS

Based on the guidelines and validated quality indictors, the optimal standard of care as the goal was defined. A clinical algorithm was developed and personal responsibilities and time limits were clearly assigned to each decision step and action. Checklists, documentation charts, and a full text supplement the algorithm. The complete pathway was adopted by representatives of all occupational groups involved in early trauma care in a consensus process.

RESULTS

Improvement potentials were identified in those areas for which the guidelines did not provide explicit recommendations. These represent the key elements of the algorithm. Pathway-specific review criteria (quality indicators) were defined for scheduled reevaluation.

CONCLUSIONS

Implementing clinical guidelines at the local level requires a problem-oriented and management-oriented elaboration towards a clinical pathway as the basis for a quantitative process and cost analysis.