Comparison of a standard and a high-concentration contrast medium protocol for MDCT angiography of the lower limb arteries.

PURPOSE: To prospectively compare a compact bolus (CB) injection protocol using high-iodine concentration contrast medium with a standard bolus (SB) injection protocol at equi-iodine doses for run-off computed tomographic angiography (CTA). MATERIALS AND METHODS: 64 patients with suspected peripheral arterial disease who underwent 40 or 64-slice run-off CTA were included in this IRB-approved study. Patients were randomized to undergo the CB protocol (32 patients, iomeprol 400mgI/mL, 100 mL, 4 mL/sec) or the SB protocol (32 patients, iomeprol 300mgI/mL, 134 mL, 4 mL/sec). Luminal contrast density (CD) values were measured and arterial opacification (AO) was scored (5-point scale). Cases of venous overlay or bolus overriding were documented. RESULTS: Overall arterial CD was significantly higher with the compact bolus (CB: 279 ± 57HU, SB: 234 ± 32HU, p = 0.0017). Segmental CD was significantly higher (p< 0.05) in 7 of 16 evaluated segments. Patency-based comparison revealed superior AO in vessels with relevant (50 - 99 %) stenoses (CB: 4.54 vs. SB: 4.18, p = 0.04). Contrast bolus overriding without pathological reasons, i. e., acute occlusions, was noted in one patient in each group. Venous overlay was observed less frequently in the CB group (CB vs. SB: 12 vs. 19 patients, n. s.; 29 of 64 legs [45 %] vs. 44 of 64 legs [69 %], p = 0.01). CONCLUSION: At equi-iodine doses, the CB protocol led to a quantitatively and qualitatively higher arterial opacification compared to the SB protocol. Therefore, a CB protocol should be favored for run-off CTA.

[Radial MRI of the hip joint for evaluation of degenerative changes in the young adult: a comparison of different sequences]. / Radiäre MRT des Hüftgelenks zur Abklärung präarthrotischer Veränderungen im jungen Erwachsenenalter: ein Vergleich verschiedener Sequenzen.

AIM: Femoroacetabular impingement has been shown to be an important cause for the development of osteoarthritis of the hip joint. Radial MRI of the hip has proven to be the diagnostic procedure of choice to differentiate which patient to operate. While examinations after instillation of contrast agents have been described, new papers have shown high accuracy without contrast medium. Since instillation of contrast medium is considered painful and poses the risk of infection, it is not performed for MRI evaluation of the hip at our institution. However, the question as to which sequence to use has not been settled yet. Therefore, four frequently used sequences using the same resolution were compared. MATERIALS AND METHODS: A retrospective analysis of T (1)-weighted (T (1)), T (2)-weighted (T (2)) and proton density sequences (the latter with and without fat saturation [PDfs and PD]) of 50 hips in 48 patients with femoro-acetabular impingement and developmental dysplasia of the hip was performed by two raters blinded to the clinical information. The different sequences were rated separately. Evaluated criteria were subjective imaging quality, power to differentiate acetabular from femoral cartilage as well as the labrum from the joint capsule, and localisation and characterisation of pathological changes in joint cartilage, the labrum and at the femoral head-neck junction. RESULTS: Subjective imaging quality was assessed to be similar for T (1), PDfs and PD, whereas it was significantly worse for T (2). In discriminating specific intraarticular structures, however, only PDfs and PD were superior. The differentiation of acetabular from femoral cartilage was possible in only 44% and 40% of T (1) and T (2) images, but in 79% and 76% of PDfs and PD images. Similar results were found for the differentiation of the acetabular labrum from its vicinity, especially the joint capsule (36%, 35%, 77% and 74%, respectively). Intralabral pathology was seen in a comparable extent in all sequences. An intramedullary oedema at the head-neck junction, however, was significantly more frequent in PDfs only (67% vs. 0%, 17% and 10% for PDfs vs. T (1), T (2) and PD). CONCLUSION: Despite their good subjective quality, T (1)- and T (2-)weighted sequences could not depict the acetabular labrum as efficiently as PD-weighted sequences. Concluding from our data, a PDfs sequence (possibly combined with a conventional PD sequence) is advantageous over T (1) and T (2) sequences. Intraarticular administration of contrast medium seems to be superfluous.

[Diagnostics of vascular diseases as a cause for acute abdomen]. / Diagnostik vaskulärer Erkrankungen als Ursache für das akute Abdomen.

Vascular pathologies are rare causes of an acute abdomen. If the cause is a vascular disease a rapid diagnosis is desired as vascular pathologies are associated with high mortality. A differentiation must be made between arterial and venous diseases. An occlusion of the superior mesenteric artery is the most common reason for acute mesenteric ischemia but intra-abdominal arterial bleeding is also of great importance. Venous pathologies include thrombotic occlusion of the portal vein, the mesenteric vein and the vena cava.Multi-detector computed tomography (MDCT) is predestined for the diagnostics of vascular diseases of the abdomen. Using multiphasic contrast protocols enables reliable imaging of the arterial and venous vessel tree and detection of disorders with high sensitivity and specificity. Although conventional angiography has been almost completely replaced by MDCT as a diagnostic tool, it is still of high importance for minimally invasive interventions, for example in the management of gastrointestinal bleeding.

[Biomechanical investigation of fixed-angle plate osteosynthesis of the proximal humerus]. / Biomechanische Untersuchung der winkelstabilen Plattenosteosynthese am proximalen Humerus.

INTRODUCTION: Proximal humeral fractures are common in the elderly population and are often associated with osteoporosis. Fixation of unstable proximal humeral fractures is problematic due to loss of fixation in osteoporotic bone. Fixed-angle devices are intended to provide superior mechanical stability due to the principle of an internal fixator. The NCB(R)-PH (non-contact-bridging proximal humerus) plate is a new fixed-angle device that locks the screws to the plate by secondary insertion of a locking cap. The aim of this study was to investigate if and to what extent NCB-PH plates applied in the locked mode provide higher mechanical stability in a proximal humerus fracture model. METHODS: For this investigation 16 (8 pairs) fresh frozen cadaveric humeri were used. An AO/ASIF 11-B 1 fracture of the proximal humerus was created in each bone and fixed with the NCB-PH plate. In a paired setting one bone was fixed with the plate in the locked mode and the other with the plate in the non-locked mode. The bones were then subjected to 100 cycles of axial loading and interfragmentary motion was measured. Bones surviving this test were subjected to load-to-failure testing and the force at which failure occurred was recorded. RESULTS: Bones fixed with the plate in the locked mode showed a statistically significant lower (51%) interfragmentary rotation compared to bones fixed with the plate in the non-locked mode. There was also a tendency for the bones fixed with the plate in the locked mode to fail first under higher forces (16%) during load-to-failure testing. CONCLUSION: The NCB-PH plate provides superior interfragmentary stability when used in the locked mode in a human cadaveric proximal humerus fracture model. Therefore, we recommend that all screws should be inserted in the locked mode. The results suggest that the NCB-PH plate in the locked mode provides higher primary postoperative stability thus permitting early functional treatment of the patient.

[CT colonography: evaluation of two 3D algorithms in a screening population]. / CT-Kolografie: Vergleich zweier Visualisierungsalgorithmen an einem Screeningkollektiv.

PURPOSE: The purpose of this multicenter study was to compare a dissection display and an endoluminal display for CT colonography (CTC) by means of detection rates and evaluation time in a screening collective. MATERIALS AND METHODS: 4 blinded readers evaluated CTC datasets from 42 patients with 55 endoscopically confirmed polyps. The datasets were read in a randomized order using two different 3D visualization methods (endoluminal view vs. dissection display; EBW 2.0.1, Philips Medical Systems, Best/NL). Patients underwent cathartic cleansing as well as stool and fluid tagging. All readers except one were experienced in performing CTC. The per-lesion/per-patient sensitivity, per-patient specificity, and evaluation time were calculated. RESULTS: The overall per-lesion sensitivity using the dissection display (and endoluminal view) was 60% (53 %) for reader 1, 58% (60%) for reader 2, 67% (71%) for reader 3 and 55% (58%) for reader 4. The per-patient sensitivity using the dissection display (and endoluminal view) was 85% (85%) for reader 1, 80% (85%) for reader 2, 95% (90%) for reader 3 and 80% (80%) for reader 4. The per-patient specificity was 68% with dissection view (77% endoluminal view) for reader 1, 82% (82%) for reader 2, 59% (59%) for reader 3 and 82% (73%) for reader 4. The experienced readers were significantly faster using the perspective-filet view. CONCLUSION: Using a dissection display of CTC datasets does not result in superior detection rates for polyps if datasets are stool and fluid-tagged. 3 out of 4 readers evaluated the datasets significantly faster with the dissection display.

Value of MDCT in preoperative local staging of rectal cancer for predicting the necessity for neoadjuvant radiochemotherapy.

PURPOSE: Neoadjuvant therapy may reduce local rectal cancer recurrence after total mesorectum extirpation. This study was performed to assess whether multi-detector row CT (MDCT) is capable of reliably differentiating UICC I (surgery) from UICC II-IV (neoadjuvant therapy). MATERIALS AND METHODS: 29 patients underwent preoperative MDCT of the abdomen in a portal venous phase. Two blinded readers independently evaluated the datasets on a dedicated workstation using axial and coronal reformations. Local tumor extension (T), nodal status (N) and distant metastases (M) were evaluated and the UICC stage was determined. Findings were correlated with postoperative histology. RESULTS: Histologically, 9 patients were UICC I; 20 UICC > I (II: 7; III: 11; IV: 2). Reader 1 correctly identified 3 / 9 as UICC I, overstaged 6 / 9, and correctly staged 20 / 20 as UICC > I. Reader 2 correctly identified 4 / 9 as UICC I, overstaged 5 / 9, understaged 4 / 20 and correctly staged 16 / 20 as UICC > I (PPV UICC I 100 % [50 %] reader 1 [reader 2], NPV 77 % [76 %], accuracy 79 % [69 %]). Reasons for overstaging by reader 1 (reader 2) included false-positive lymph nodes (LN) in 5 (5), overgrading T 1 tumors as T 3 in 1(0), and T overgrading in 4 / 5 (2 / 5) patients with false-positive LN. CONCLUSION: MDCT failed to reliably identify UICC I in rectal cancer patients. Therefore, a strategy based solely on MDCT to identify patients who would benefit from neoadjuvant therapy does not seem appropriate.

[Current imaging for rectal cancer]. / Aktuelle Bildgebung beim Rektumkarzinom.

Rectal cancer is one of the most common causes of death from cancer. Accurate staging is necessary for optimal treatment. The tumor node metastasis (TNM) system is used to describe numerically the anatomical extent of cancer. Various diagnostic methods provide accurate staging. Endorectal ultrasound (EUS) and magnetic resonance tomography (MR) are most adequate for determining tumor stage. Moreover, MR is highly accurate in predicting the circumferential resection margin. Accurate node staging remains however difficult with both EUS and MR. Modern multidetector row CT is predestined for detecting distant metastases as it is a widespread, fast, and reproducible method.

Evaluation of acute mesenteric ischemia: accuracy of biphasic mesenteric multi-detector CT angiography.

The purpose of this study was to explore the accuracy of multi-detector row helical CT (MDCT), using a biphasic mesenteric angiography protocol for evaluation of acute mesenteric ischemia (AMI). In total, 79 consecutive patients with clinical signs of AMI underwent contrast enhanced 16- or 40-channel MDCT. MDCT findings were correlated with surgery, endoscopy and clinical outcome. Sensitivity, specificity, and positive and negative predictive values were calculated using the patients in which AMI had been excluded as a control group. In 28 patients the final diagnosis was AMI. In 27 patients (96.4%) MDCT correctly diagnosed AMI (specificity of 97.9%). A sensitivity of 93%, specificity of 100%, and positive and negative predictive values of 100% and 94%, respectively were achieved for the CT findings of visceral artery occlusion, intestinal pneumatosis, portomesenteric venous gas or bowel wall thickening in combination with either portomesenteric thrombosis or solid organ infarction. Our findings suggest that mesenteric MDCT angiography is an accurate tool for fast diagnostic work-up of patients with suspected AMI.

Pitfalls in detection of acute gastrointestinal bleeding with multi-detector row helical CT.

Contrast-enhanced multi-detector row helical CT angiography is establishing itself as an accurate, rapid, and non-invasive diagnostic modality in patients with acute gastrointestinal bleeding. On arterial phase MDCT images ongoing hemorrhage can be revealed as an area of active extravasation of contrast material within the bowel lumen. This pictorial essay gives a short overview of current diagnostic modalities in assessing acute GI tract bleeding, typical MDCT findings, and depicts potential pitfalls in the detection of acute GI bleeding with MDCT.

Evaluation of accordance of magnetic resonance volumetric and flow measurements in determining ventricular stroke volume in cardiac patients.

BACKGROUND: Cardiovascular magnetic resonance imaging (CMR) has become an established noninvasive method for evaluating ventricular function utilizing three-dimensional volumetry. Postprocessing of volumetric measurements is still tedious and time consuming. Stroke volumes obtained by flow quantification across the aortic root or pulmonary trunk could be utilized to increase both speed of workflow and accuracy. PURPOSE: To assess accuracy of stroke volume quantification using MR volumetric imaging compared to flow quantification in patients with various cardiac diseases. Strategies for the augmentation of accuracy in clinical routine were deduced. MATERIAL AND METHODS: 78 patients with various cardiac diseases-excluding intra- or extracardiac shunts, regurgitant valvular defects, or heart rhythm disturbance-underwent cardiac function analysis with flow measurements across the aortic root and cine imaging of the left ventricle. Forty-six patients additionally underwent flow measurements in the pulmonary trunk and cine imaging of the right ventricle. RESULTS: Left ventricular stroke volume (LVSV) and stroke volume of the aortic root (SVAo) correlated with r=0.97, and Bland-Altman analysis showed a mean difference of 0.11 ml and a standard error of estimation (SEE) of 4.31 ml. Ninety-two percent of the data were within the 95% limits of agreement. Right ventricular stroke volume (RVSV) and stroke volume of the pulmonary trunk (SVP) correlated with a factor of r=0.86, and mean difference in the Bland-Altman analysis was fixed at -2.62 ml (SEE 8.47 ml). For RVSV and SVP, we calculated r=0.82, and Bland-Altman analysis revealed a mean difference of 1.27 ml (SEE 9.89 ml). LVSV and RVSV correlated closely, with r=0.91 and a mean difference of 2.79 ml (SEE 7.17 ml). SVAo and SVP correlated with r=0.95 and a mean difference of 0.50 ml (SEE 5.56 ml). CONCLUSION: Flow quantification can be used as a guidance tool, providing accurate and reproducible stroke volumes of both ventricles. Combining both offers a highly accurate tool to gauge ventricular function in a routine clinical setting, increasing workflow speed.

Detection and localization of acute upper and lower gastrointestinal (GI) bleeding with arterial phase multi-detector row helical CT.

The purpose of this study was to evaluate the accuracy of multi-detector row helical CT (MDCT) for detection and localization of acute upper and lower gastrointestinal (GI) hemorrhage or intraperitoneal bleeding. Thirty-six consecutive patients with clinical signs of acute bleeding underwent biphasic (16- or 40-channel) MDCT. MDCT findings were correlated with endoscopy, angiography or surgery. Among the 36 patients evaluated, 26 were examined for GI bleeding and 10 for intraperitoneal hemorrhage. Confirmed sites of GI bleeding were the stomach (n = 5), duodenum (n = 5), small bowel (n = 6), large bowel (n = 8) and rectum (n = 2). The correct site of bleeding was identifiable on MDCT in 24/26 patients with GI bleeding. In 20 of these 24 patients, active CM extravasation was apparent during the exam. Among the ten patients with intraperitoneal hemorrhage, MDCT correctly identified the bleeding source in nine patients. Our findings suggest that fast and accurate localization of acute gastrointestinal and intraperitoneal bleeding is achievable on MDCT.

Acute gastrointestinal bleeding: value of MDCT.

Contrast-enhanced multidetector row helical computed tomography (MDCT) scanning is establishing itself as a rapid, noninvasive, and accurate diagnostic method in suspected acute gastrointestinal bleeding. Active bleeding can be depicted as an area of focal high attenuation within the bowel lumen on arterial phase MDCT images. New MDCT technologies facilitate three-dimensional image reconstruction, and higher temporal resolution is available with new MDCT scanner generations. This allows for the acquisition of arterial- and portal-venous phase images of the whole abdomen, revealing potential bleeding sources and simultaneously depict morphological changes in the abdomen, such as intestinal tumors. This article gives an overview of available diagnostic modalities in assessing gastrointestinal (GI) tract hemorrhage, with a special emphasis on new MDCT technology.

[Interobserver agreement in the assessment of pulmonary infiltrates on chest radiography in community-acquired pneumonia]. / Detektion pneumonischer Infiltrate bei ambulant erworbener Pneumonie: Ubereinstimmung in der Befundung der Röntgen-Thoraxaufnahme.

PURPOSE: To assess interobserver agreement (IOA) in the diagnosis of pulmonary infiltrates on chest x-rays for patients with community-acquired pneumonia (CAP). MATERIALS AND METHODS: From 7/2002 to 12/2005, 806 adults with CAP were included in the multicenter study "CAPNETZ" (7 hospitals). Inclusion criteria were clinical signs of pneumonia and pulmonary opacification on chest x-rays. Each x-ray was reevaluated by two radiologists from the university hospital in consensus reading against the interpreter at the referring hospital in regard to: presence of infiltrate (yes/no/equivocal), transparency (50%), localization, and pattern of infiltrates (alveolar/interstitial). The following parameters were documented: digital or film radiography, hospitalization, fever, findings of auscultation, microbiological findings. RESULTS: The overall IOA concerning the detection of infiltrates was 77.7% (n=626; CI 0.75-0.81), the infiltrates were not verified in 16.4% (n=132) by the referring radiologist with equivocal findings in 5.9% (n=48). The IOA of the different clinical centers varied between 63.2% (n=38, CI 0.48-0.78) and 92.3% (n=65, CI 0.86-0.99). The IOA for the diagnosis of infiltrates was significantly higher for inpatients with 82.6% (n=546; CI 0.80-0.85) than for outpatients with 55.2 % (n=80; CI 0.47-0.63), p<0.0001. The IOA of infiltrates with a transparency >50% was 95.1% (n=215; CI 0.92-0.98) versus 80.4% (n=403; CI 0.77-0.84) for infiltrates with a transparency >50% (p<0.0001). In patients with positive auscultation, the IOA was higher (p=0,034). Chest x-rays of patients with antibiotic therapy or an alveolar infiltrate showed more equivocal findings compared to patients without these features. CONCLUSION: There is considerable interobserver variability in the diagnosis of pulmonary infiltrates on chest radiographs. The IOA is higher in more opaque infiltrates, positive auscultation and inpatients.

[Complaints in the follow-up of conservatively treated distal radius fractures--predictors in the initial radiograph]. / Beschwerden im Verlauf nach konservativ behandelten distalen Radiusfrakturen--Prädiktoren aus der initialen Röntgenaufnahme.

PURPOSE: Radius fractures are frequent in adults, and the long-term results of conservative treatment remain disappointing. This study examines predictors for the clinical outcome in the initial radiograph. This will help to identify patients who will benefit from surgical treatment. MATERIALS AND METHODS: A cohort study including a standardized telephone interview (Cooney score) was used to identify all conservatively treated patients with a distal radius fracture over a five-year period. The additional selection criteria were: over 15 years old, initial X-ray available, patient reachable by phone for the follow-up interview. The following measurements were taken from the initial radiograph: radius-base angle, radial shortening, radiopalmar angle and intraarticular displacement. Correlations and a simple test to predict negative outcome were computed. RESULTS: Of the initially identified 2211 patients with distal radius fracture, 179 also fulfilled the other criteria. The patients were 56.2 years old on average (standard deviation SD = +/- 22.45 years) and 72 % were female. 60 % of the fractures were on the right side. The average follow-up was 4.3 years (SD +/- 1.66). The Cooney score results averaged 85 points (with 100 being the optimal and maximum score), indicating good or very good functional results in the long term follow-up for 61 % of patients. However, 31 % received a rating of fair or poor and therefore had an unfavorable outcome. With respect to the correlations, age and shortening of the radius (but not gender) had a significant influence on the functional result. Using an age of 75 years or above and a radial shortening of at least 4 mm to predict an unfavorable outcome, the sensitivity is only 16 %, but the positive predictive value is 73 % and the specificity is 96 %. CONCLUSION: In the analysis of the initial radiographs after distal radius fracture, age and radial shortening primarily correlate with functional results after four years after conservative treatment. Using the values age > or = 75 and radial shortening > or = 4 mm, it is possible to predict an unfavorable functional outcome with a positive predictive value of 73 %. This could aid in the indication of operative treatment.

A retrospective evaluation of patient acceptance of computed tomography colonography ("virtual colonoscopy") in comparison with conventional colonoscopy in an average risk screening population.

PURPOSE: To evaluate patient acceptance of computed tomography (CT) colonography compared with conventional colonoscopy by means of a self-assessed questionnaire. MATERIAL AND METHODS: Four-hundred-and-one patients with valid address information from our patient collective were preselected. Patient acceptance was evaluated retrospectively using a self-assessed questionnaire. The patients underwent CT colonography in our institution using 4x or 16x multi-detector row (MDR) CT. Two-hundred-and-forty-six patients returned a completed questionnaire, 157 of these indicating that they had undergone both virtual and conventional colonoscopy. RESULTS: One-hundred-and-twenty (76.4%) of the 157 patients would undergo another CT colonography if necessary, while only 14 patients would not. One-hundred-and-sixteen (73.9%) patients favored the actual examination procedure of CT colonography (P<0.0001), while only 6.4% preferred the conventional method. Preparation prior to CT colonography was experienced as more convenient than preparation prior to conventional colonoscopy (52.2% versus 14%). CONCLUSION: CT colonography was preferred in terms of both preparation and the actual procedure itself.

[An unusual foreign body in the upper gastrointestinal tract causing nonspecific abdominal pain]. / Ungewöhnlicher Fremdkörper im oberen Gastrointestinaltrakt als Ursache eines unklaren Abdomens.

The risk of penetration of vena cava filters through the wall of the vena cava is estimated to be as high as 25%, although clinical symptoms are observed far less frequently in patients with this complication. Due to the close relationship between vena cava and duodenum, the latter can be injured by dislocated filters. We describe the presentation, evaluation, and treatment of a patient with a cava filter protruding into the duodenum, and we review the literature.

[GI hemorrhage with fulminant shock induced by jejunal gastrointestinal stromal tumor (GIST) coincident with duodenal neuroendocrine carcinoma (NET) + neurofibromatosis (NF) -- case report and review of the literature]. / Hämorrhagischer Schock bei Doppelmalignom: Gastrointestinaler Stromatumor (GIST) und neuroendokrines Karzinom bei Morbus Recklinghausen.

BACKGROUND: The incidence of neuroendocrine tumors (NET) and of gastrointestinal stromal tumors (GIST) is 0.5 and 1 - 2 in 100,000; the prevalence of neurofibromatosis is 1 in 3000 live births in Western countries. CASE REPORT: A 43-year-old white woman with a six-month history of meleana, paleness, vertigo and fatigue was not referred to any gastrointestinal doctor for diagnostic work-up. Finally, she collapsed and was admitted to hospital because of an acute gastrointestinal bleeding. Endoscopically the source of bleeding could not be localized while blood in the duodenum and proximal jejunum was demonstrable. The source of bleeding could not be identified by endoscopy, CT scan or angiography. The patient developed a fulminant gastrointestinal hemorrhage with hemoglobin levels below 3.5 g %. An emergency laparotomy and pylorus-preventing Whipple operation was performed. Pathological studies showed a GIST with 3.5 cm diameter of the proximal jejunum which was the source of bleeding. Coincidentally a neuroendocrine carcinoma of the duodenum was found. CONCLUSION: This case is the first presentation of the coincidence of a neuroendocrine carcinoma of the duodenum with a jejunal bleeding gastrointestinal stromal tumor in neurofibromatosis type1 which led to hemorrhagic shock. In neurofibromatosis -- even if non-symptomatic -- the increased incidence of tumor needs to be considered.

[Local radiofrequency ablation of liver lesions--possibilities and limitations]. / Lokale Radiofrequenzablation von Leberherden--Möglichkeiten und Grenzen.

Radiofrequency ablation (RFA) is currently the most established technique for the local destruction of tumors within the liver. It is technically straightforward, can be repeated and combines a high efficiency in tissue destruction with a low to moderate incidence of complications. This review explains the principle of RFA and lists currently available systems. In addition, the rationale behind RFA is discussed, and an overview of clinical indications, results and complications is presented. One of the main problems in assessing the clinical value of RFA is the fact that no large and controlled randomized studies are available, while the number of ablations and treated tumor entities are steadily increasing. From a technical point of view, the major problem is the still limited volume of necrosis that is achievable. The indication for RFA has to be discussed as interdisciplinary. A complete tumor necrosis should be the aim of all ablations, with the exception of symptomatic metastases of neuroendocrine tumors. The value of additional chemotherapy to RFA is still unclear, especially in the treatment of liver metastases.