-
[show abstract]
[hide abstract]
ABSTRACT: BackgroundStudies of treatment with octreotide of patients with hepatocellular carcinoma (HCC) gave conflicting results. We analyzed
retrospectively the survival of our patients treated with octreotide monotherapy and compared it to stage-matched patients
who received either TACE, multimodal therapy or palliative care.
Methods95 patients seen at the department of Gastroenterology and Hepatology, Medical University of Vienna with HCC in BCLC stage
A or B, who received either TACE, multimodal therapy, long-acting octreotide or palliative care were reviewed for this retrospective
study.
ResultsSurvival rates of patients with BCLC stage B and any "active" treatment (long-acting octreotide, TACE or multimodal therapy)
were significantly higher (22.4, 22.0, 35.5 months) compared to patients who received palliative care only (2.9 months). Survival
rates of patients with BCLC stage A and "active" treatment (31.4, 37.3, 40.2 months) compared to patients who received only
palliative care (15.1 months) did not show statistically significant differences. Octreotide monotherapy showed a similar
outcome compared to patients who received TACE or multimodal therapy.
ConclusionSurvival under octreotide treatment was not different compared to TACE or multimodal therapy and might be a therapeutic option
for patients with HCC.
Journal of Experimental & Clinical Cancer Research 04/2012; 28(1):1-8. · 2.15 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Studies of treatment with octreotide of patients with hepatocellular carcinoma (HCC) gave conflicting results. We analyzed retrospectively the survival of our patients treated with octreotide monotherapy and compared it to stage-matched patients who received either TACE, multimodal therapy or palliative care.
95 patients seen at the department of Gastroenterology and Hepatology, Medical University of Vienna with HCC in BCLC stage A or B, who received either TACE, multimodal therapy, long-acting octreotide or palliative care were reviewed for this retrospective study.
Survival rates of patients with BCLC stage B and any "active" treatment (long-acting octreotide, TACE or multimodal therapy) were significantly higher (22.4, 22.0, 35.5 months) compared to patients who received palliative care only (2.9 months). Survival rates of patients with BCLC stage A and "active" treatment (31.4, 37.3, 40.2 months) compared to patients who received only palliative care (15.1 months) did not show statistically significant differences. Octreotide monotherapy showed a similar outcome compared to patients who received TACE or multimodal therapy.
Survival under octreotide treatment was not different compared to TACE or multimodal therapy and might be a therapeutic option for patients with HCC.
Journal of Experimental & Clinical Cancer Research 11/2009; 28:142. · 2.15 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: In this article, the authors evaluate a merit function for 2D/3D registration called stochastic rank correlation (SRC). SRC is characterized by the fact that differences in image intensity do not influence the registration result; it therefore combines the numerical advantages of cross correlation (CC)-type merit functions with the flexibility of mutual-information-type merit functions. The basic idea is that registration is achieved on a random subset of the image, which allows for an efficient computation of Spearman's rank correlation coefficient. This measure is, by nature, invariant to monotonic intensity transforms in the images under comparison, which renders it an ideal solution for intramodal images acquired at different energy levels as encountered in intrafractional kV imaging in image-guided radiotherapy. Initial evaluation was undertaken using a 2D/3D registration reference image dataset of a cadaver spine. Even with no radiometric calibration, SRC shows a significant improvement in robustness and stability compared to CC. Pattern intensity, another merit function that was evaluated for comparison, gave rather poor results due to its limited convergence range. The time required for SRC with 5% image content compares well to the other merit functions; increasing the image content does not significantly influence the algorithm accuracy. The authors conclude that SRC is a promising measure for 2D/3D registration in IGRT and image-guided therapy in general.
Medical Physics 08/2009; 36(8):3420-8. · 2.83 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: In order to assess the clinical relevance of a slice-to-volume registration algorithm, this technique was compared to manual registration. Reformatted images obtained from a diagnostic CT examination of the lower abdomen were reviewed and manually registered by 41 individuals. The results were refined by the algorithm. Furthermore, a fully automatic registration of the single slices to the whole CT examination, without manual initialization, was also performed. The manual registration error for rotation and translation was found to be 2.7+/-2.8 degrees and 4.0+/-2.5 mm. The automated registration algorithm significantly reduced the registration error to 1.6+/-2.6 degrees and 1.3+/-1.6 mm (p = 0.01). In 3 of 41 (7.3%) registration cases, the automated registration algorithm failed completely. On average, the time required for manual registration was 213+/-197 s; automatic registration took 82+/-15 s. Registration was also performed without any human interaction. The resulting registration error of the algorithm without manual pre-registration was found to be 2.9+/-2.9 degrees and 1.1+/-0.2 mm. Here, a registration took 91+/-6 s, on average. Overall, the automated registration algorithm improved the accuracy of manual registration by 59% in rotation and 325% in translation. The absolute values are well within a clinically relevant range.
European Radiology 07/2009; 19(11):2647-53. · 3.22 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Abstract
Background
Studies of treatment with octreotide of patients with hepatocellular carcinoma (HCC) gave conflicting results. We analyzed retrospectively the survival of our patients treated with octreotide monotherapy and compared it to stage-matched patients who received either TACE, multimodal therapy or palliative care.
Methods
95 patients seen at the department of Gastroenterology and Hepatology, Medical University of Vienna with HCC in BCLC stage A or B, who received either TACE, multimodal therapy, long-acting octreotide or palliative care were reviewed for this retrospective study.
Results
Survival rates of patients with BCLC stage B and any "active" treatment (long-acting octreotide, TACE or multimodal therapy) were significantly higher (22.4, 22.0, 35.5 months) compared to patients who received palliative care only (2.9 months). Survival rates of patients with BCLC stage A and "active" treatment (31.4, 37.3, 40.2 months) compared to patients who received only palliative care (15.1 months) did not show statistically significant differences. Octreotide monotherapy showed a similar outcome compared to patients who received TACE or multimodal therapy.
Conclusion
Survival under octreotide treatment was not different compared to TACE or multimodal therapy and might be a therapeutic option for patients with HCC.
Journal of Experimental & Clinical Cancer Research. 01/2009;
-
[show abstract]
[hide abstract]
ABSTRACT: To report about the endovascular treatment of isolated iliac artery aneurysms (IIAA) with stentgraft placement and transluminal or CT-guided embolization of the internal iliac artery or the combination of these methods.
Over a period of 5.6 years, 36 interventions were performed in 20 patients with 23 IIAAs. In a retrospective analysis patient records were reviewed. The CT-angiography follow-up was evaluated for the presence of re-perfusion of the IIAA and for change of aneurysm diameter.
Primary success was achieved in 15/23 aneurysms (65%), and secondary success in 21/23 aneurysms (91%). In 5/23 cases two interventions and in 1/23 cases three interventions were necessary to achieve secondary success. Embolization alone, as a therapy for aneurysms involving only the internal iliac artery, had a success rate of 27%. No procedure-related minor or major complications occurred. Mean decrease of aneurysm size during a mean observation period of 14.1 months was 6.9% which was not significant (p=0.3; 95% confidence interval +7-21%).
Endovascular therapy of isolated iliac artery aneurysms performed percutaneously has become a treatment alternative to open surgical repair. This method is feasible and safe with low procedure-related morbidity and mortality. However, on average more than one intervention has to be performed to achieve successful permanent exclusion of the aneurysm and embolization alone in isolated internal iliac artery aneurysms is not sufficient.
European Journal of Radiology 04/2008; 65(3):491-7. · 2.61 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Current merit functions for 2D/3D registration usually rely on comparing pixels or small regions of images using some sort of statistical measure. Problems connected to this paradigm the sometimes problematic behaviour of the method if noise or artefacts (for instance a guide wire) are present on the projective image. We present a merit function for 2D/3D registration which utilizes the decomposition of the X-ray and the DRR under comparison into orthogonal Zernike moments; the quality of the match is assessed by an iterative comparison of expansion coefficients. Results in a imaging study on a physical phantom show that--compared to standard cross--correlation the Zernike moment based merit function shows better robustness if histogram content in images under comparison is different, and that time expenses are comparable if the merit function is constructed out of a few significant moments only.
Medical image computing and computer-assisted intervention : MICCAI ... International Conference on Medical Image Computing and Computer-Assisted Intervention. 02/2008; 11(Pt 2):964-71.
-
[show abstract]
[hide abstract]
ABSTRACT: The concept of functional endoscopic sinus surgery, developed by Messerklinger in the early 1970s revolutionized and radically
altered the techniques used for the diagnosis and treatment of patients with sinus disease (Messerklinger 1994; Stammberger and Posawetz 1990). Messerklingers initial work, however, was conducted with information derived from plain films and conventional polytomography.
This technique has been replaced by computed tomography (CT) for many years, which is now considered an essential component
to identify anatomic variants that may compromise the ventilation of the sinuses and can demonstrate areas of diseased mucosa
that are responsible for recurrent disease. The CT scan further provides valuable information about the presence of potential
hazards such as septations of the frontal or sphenoid sinuses, the proximity and location of the orbit, the internal carotid
artery and optic nerve to areas of disease. Furthermore, CT is the ideal method for the demonstration of the delicate bony
structures of the ethmoid labyrinth.
12/2007: pages 151-171;
-
[show abstract]
[hide abstract]
ABSTRACT: A wide variety of artifacts can be seen in clinical MR imaging. This review describes the most important and most prevalent of them, including magnetic susceptibility artifacts and motion artifacts, aliasing, chemical-shift, zipper, zebra, central point, and truncation artifacts. Although the elimination of some artifacts may require a service engineer, the radiologist and MR technologist have the responsibility to recognize MR imaging problems. This review shows the typical MR appearance of the described artifacts, explains their physical basis, and shows the way to solve them in daily practice.
European Radiology 06/2007; 17(5):1242-55. · 3.22 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Registration of single slices from FluoroCT, CineMR, or interventional magnetic resonance imaging to three dimensional (3D) volumes is a special aspect of the two-dimensional (2D)/3D registration problem. Rather than digitally rendered radiographs (DRR), single 2D slice images obtained during interventional procedures are compared to oblique reformatted slices from a high resolution 3D scan. Due to the lack of perspective information and the different imaging geometry, convergence behavior differs significantly from 2D/3D registration applications comparing DRR images with conventional x-ray images. We have implemented a number of merit functions and local and global optimization algorithms for slice-to-volume registration of computed tomography (CT) and FluoroCT images. These methods were tested on phantom images derived from clinical scans for liver biopsies. Our results indicate that good registration accuracy in the range of 0.50 and 1.0 mm is achievable using simple cross correlation and repeated application of local optimization algorithms. Typically, a registration took approximately 1 min on a standard personal computer. Other merit functions such as pattern intensity or normalized mutual information did not perform as well as cross correlation in this initial evaluation. Furthermore, it appears as if the use of global optimization algorithms such as simulated annealing does not improve reliability or accuracy of the registration process. These findings were also confirmed in a preliminary registration study on five clinical scans. These experiments have, however, shown that a strict breath-hold protocol is inevitable when using rigid registration techniques for lesion localization in image-guided biopsy retrieval. Finally, further possible applications of slice-to-volume registration are discussed.
Medical Physics 02/2007; 34(1):246-55. · 2.83 Impact Factor
-
Melanie Blum,
Christian Mueller,
Markus Peck-Radosavljevic,
Friedrich Wrba,
Gabriela Berlakovich,
Ferdinand Mühlbacher,
Rudolf Steiniger,
Maria Speiser,
Mario Pones,
Michael Hüpfl,
Johannes Lammer, Joachim Kettenbach
[show abstract]
[hide abstract]
ABSTRACT: It was the objective of this study to evaluate MR-guided, percutaneous ethanol injection of hepatocellular carcinoma in ten patients scheduled for liver transplantation. Using a 0.2 T open MR scanner (Magnetom Open, Siemens Medical Systems, Erlangen, Germany) and percutaneous instillation of ethanol, 12 liver tumors (median tumor volume, 6.3; range, 0.6-43.2 ccm) were treated. Coagulation necrosis, morbidity, and post-transplant histology were assessed. No major complications were observed. A mean of 16.4+/-11.4 ml ethanol was injected for each tumor. The median volume of the ablation necrosis was 12.3 (range, 0.3-48.3) ccm. Three tumors were retreated and complete radiological necrosis before liver transplantation was found in eight of 12 tumors (67%). One patient developed multifocal disease and was excluded from transplantation; thus nine of ten patients underwent liver transplantation within 3.9+/-3.1 months. In the explants, satellite nodules (n = 2), new liver tumors (n = 2) and a complete necrosis were found in five of 12 treated tumors (42%). During follow-up (median 41.3; range, 0.4-86.1 months), three patients died, but no tumor-seeding or post-transplantation recurrence occurred. MR-guided ethanol injection is feasible, and may delay tumor progression. However, the local recurrence rate is high, and the spatial resolution of a low-field MR scanner limits the detection of small tumors.
Minimally Invasive Therapy & Allied Technologies 02/2007; 16(4):230-40. · 0.94 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Computer-aided implant dentistry (CAID), the direct translation of preoperative prosthetic planning to the operating theater
by means of image guidance technologies, is a novel application of computer aided surgery (CAS). This work deals with the
application of a modular software system for computer-aided interventions to CAID. The system is based on AVW-2.5, a software
library dedicated to biomedical image processing, and a custom interface for communication with an optical tracker. A specific
CAID toolset was also manufactured. We assessed the performance of two different point-based registration algorithms for this
specific application of computer-aided preprosthetic surgery on several jaw models. The fiducial localization error (FLE)
achievable with our system was found to be 0.7 mm, the fiducial registration error (FRE) accounted for 0.7 mm, and the target
registration error TRE (the overall navigation accuracy) was found to be 1.3 mm. Since these results compare well to the resolution
of the high-resolution computed tomography scan used we consider the precision of our system to be sufficient. Future enhancements
of our system include the implementation of a medical augmented reality display system and the customization of the software
package for exploration of other clinical applications of CAS.
09/2006: pages 883-891;
-
European Journal of Radiology 09/2006; 59(2):131-2. · 2.61 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: To compare two different expandable electrodes in radiofrequency ablation of renal cell carcinoma.
Percutaneous ablation was performed at two centers using either an expandable 7F umbrella-shaped LeVeen probe (diameter 2-4 cm) and a 200-W generator (group A), or an expandable Starburst XL electrode with a 150-W generator (group B). From each center, eight patients with one tumor each were matched retrospectively with regard to tumor volume, which was 9.71+/-6.43 cm3 for group A and 8.74+/-4.35 cm3 for group B (mean tumor diameter: 2.47+/-0.9 cm versus 2.50+/-0.4 cm, respectively). An unpaired t-test showed no significant difference in tumor volume between the two groups (p=0.820).
Sixteen patients with 16 tumors were treated. The primary technical success of radiofrequency ablation was 94% (15 of 16 patients). After retreatment of residual tumor in one patient from group B, secondary technical success was 100%. No major complications were observed. The resulting mean volume of the almost spherical necroses was 21.1+/-9.1 cm3 versus 14.6+/-6.7 cm3 for groups A and B (diameter of necrosis: 3.5+/-0.7 cm versus 3.1+/-0.6 cm, respectively). A Mann-Whitney U-test showed no significant difference in necrosis volume between the two groups (CI [-0.215; 0.471]; p=0.2892). The calculated shape value of S (ratio of length to height of the coagulation necrosis) was 0.9+/-0.1 and 1.0+/-0.1 for groups A and B, respectively. No local recurrence was observed during a mean follow-up of 14.8+/-11.6 months, while extrarenal tumor progression occurred in three patients.
No significant differences in coagulation volume and shape were found after RF ablation of renal cell carcinoma using two different expandable electrodes. To avoid local recurrence, however, accurate placement of probes and appropriate expansion of the electrode is necessary.
European Journal of Radiology 09/2006; 59(2):133-9. · 2.61 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: To evaluate the outcome of 16 patients after percutaneous radiofrequency ablation of renal tumors.
Sixteen patients (nine women, seven men; mean age, 61+/-9 years) with 24 unresectable renal tumors (mean volume, 4.3+/-4.3 cm3) underwent CT-guided (n=20) or MR imaging-guided (n=4) percutaneous radiofrequency ablation using an expandable electrode (Starburst XL, RITA Medical Systems, Mountain View, CA) with a 150-W generator. The initial follow-up imaging was performed within 1-30 days after RF ablation, then at 3-6 month intervals using either CT or MRI. Residual tumor volume and coagulation necrosis was assessed, and statistical correlation tests were obtained to determine the strength of the relationship between necrosis volume and number of ablations.
Overall, 97 overlapping RF ablations were performed (mean, 3.5+/-1.5 ablations per tumor) during 24 sessions. Five or more RF ablations per tumor created significant larger necrosis volumes than 1-2 (p=.034) or 3-4 ablations (p=.020). A complete ablation was achieved in 20/24 tumors (primary technical success, 83%; mean volume of coagulation necrosis: 10.2+/-7.2 cm3). Three of four residual tumors were retreated and showed complete necrosis thereafter. Three major complications (one percuatneous urinary fistula and two ureteral strictures) were observed after RF ablation. No further clinically relevant complications were observed and renal function remained stable. During a mean follow-up of 11.2 months (range, 0.2-31.5), 15/16 patients (94%) were alive. Only one patient had evidence of local recurrent tumor.
The midterm results of percutaneous RF ablation for renal tumors are promising and show that RF ablation is well-suited to preserve renal function.
European Journal of Radiology 09/2006; 59(2):183-9. · 2.61 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Acute type A dissections are a life threatening condition requiring immediate surgical intervention to avoid aortic rupture or pericardial tamponade. Success of surgical intervention is markedly limited in those patients with advanced age, neurological deficits, and multiple co-morbidities at the time of treatment. We report the successful endovascular stent-graft treatment in a patient suffering from an acute type A dissection. Due to the presence of multiple comorbidities the patient was considered too high risk for surgical treatment.
The Annals of thoracic surgery 09/2006; 82(2):747-9. · 3.74 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: We present a case of a primary mesenteric ectopic gastrointestinal stromal tumor. The pathologic characteristics of this neoplasm, autonomic nerve/ganglionic differentiation and presentation as a huge mass with small synchronous nodules, have not been previously described in the literature.
European Radiology 03/2006; 16(2):422-7. · 3.22 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: In this paper we report on current experience and review magnetic resonance safety protocols and literature in order to define practices surrounding MRI-guided interventional and surgical procedures. Direct experience, the American College of Radiology White paper on MR Safety, and various other sources are summarized. Additional recommendations for interventional and surgical MRI-guided procedures cover suite location/layout, accessibility, safety policy, personnel training, and MRI compatibility issues. Further information is freely available for sites to establish practices to minimize risk and ensure safety. Interventional and intraoperative MRI is emerging from its infancy, with twelve years since the advent of the field and well over 10,000 cases collectively performed. Thus, users of interventional and intraoperative MRI should adapt guidelines utilizing universal standards and terminology and establish a site-specific policy. With policy enforcement and proper training, the interventional and intraoperative MR imaging suite can be a safe and effective environment.
Minimally Invasive Therapy & Allied Technologies 02/2006; 15(2):53-64. · 0.94 Impact Factor
-
Robert Sauermann,
Rudolf Karch,
Herbert Langenberger, Joachim Kettenbach,
Bernhard Mayer-Helm,
Martina Petsch,
Claudia Wagner,
Thomas Sautner,
Rainer Gattringer,
Georgios Karanikas,
Christian Joukhadar
[show abstract]
[hide abstract]
ABSTRACT: The present study was performed to evaluate the ability of fosfomycin, a broad-spectrum antibiotic, to penetrate into abscess fluid. Twelve patients scheduled for surgical or computer tomography-guided abscess drainage received a single intravenous dose of 8 g of fosfomycin. The fosfomycin concentrations in plasma over time and in pus upon drainage were determined. A pharmacokinetic model was developed to estimate the concentration-time profile of fosfomycin in pus. Individual fosfomycin concentrations in abscess fluid at drainage varied substantially, ranging from below the limit of detection up to 168 mg/liter. The fosfomycin concentrations in pus of the study population correlated neither with plasma levels nor with the individual ratios of abscess surface area to volume. This finding was attributed to highly variable abscess permeability. The average concentration in pus was calculated to be 182 +/- 64 mg/liter at steady state, exceeding the MIC(50/90)s of several bacterial species which are commonly involved in abscess formation, such as streptococci, staphylococci, and Escherichia coli. Hereby, the exceptionally long mean half-life of fosfomycin of 32 +/- 39 h in abscess fluid may favor its antimicrobial effect because fosfomycin exerts time-dependent killing. After an initial loading dose of 10 to 12 g, fosfomycin should be administered at doses of 8 g three times per day to reach sufficient concentrations in abscess fluid and plasma. Applying this dosing regimen, fosfomycin levels in abscess fluid are expected to be effective after multiple doses in most patients.
Antimicrobial Agents and Chemotherapy 12/2005; 49(11):4448-54. · 4.84 Impact Factor
-
Angela Heiden, Joachim Kettenbach,
Peter Fischer,
Bettina Schein,
Ahmed Ba-Ssalamah,
Richard Frey,
Mohammad Mehdi Naderi,
Talin Gulesserian,
Daniela Schmid,
Siegfried Trattnig,
Herwig Imhof,
Siegfried Kasper
[show abstract]
[hide abstract]
ABSTRACT: White matter hyperintensities (WMHs) on T(2)-weighted magnetic resonance imaging (MRI) of the brain are associated with advanced age and late-life depression. Most investigations predominantly found these lesions in frontal lobe and basal ganglia supporting the hypothesis of a fronto-striatal dysfunction in depression. A prospective study was undertaken to investigate the association between extent of WMHs and clinical outcome in elderly depressed patients.
Thirty-one non-demented depressed subjects underwent a 1.5 T cranial MRI scan. The MRI scans were analysed in consensus by two experienced radiologists. Each MRI scan was assessed for presence and extent of WMHs, which are differentiated in periventricular hyperintensities (PVHs) and deep white matter hyperintensities (DWMHs). A total of 21 patients of the original cohort of 31 patients were re-assessed 5 years after baseline assessment. We ascertained the severity of depressive symptoms, the longitudinal course of depression, the cognitive decline and the global assessment of functioning at follow-up visit.
(1) Subjects with greater extent of WMHs had a significant higher Hamilton Depression Rating Scale (HAM-D) score, (2) had more severe longitudinal courses of depression (3) and had a lower Mini-Mental State Examination (MMSE) score.
WMHs on MRI are associated with poorer outcome in elderly depressed subjects. Further studies are needed to evaluate WHMs as prognostic factor for an appropriate treatment decision-making.
Journal of Psychiatric Research 06/2005; 39(3):285-93. · 4.66 Impact Factor
