Complexity of PEComas : Diagnostic approach, molecular background, clinical management.

Perivascular epithelioid cell neoplasms (PEComas) are a family of mesenchymal neoplasms with features of both melanotic and smooth muscle differentiation. PEComa morphology is highly variable and encompasses epithelioid to spindle cells often with clear cytoplasm and prominent nucleoli. Molecularly, most PEComas are defined by a loss of function of the TSC1/TSC2 complex. Additionally, a distinct small subset of PEComas harboring rearrangements of the TFE3 (Xp11) gene locus has been identified. By presenting a series of three case reports with distinct features, we demonstrate diagnostic pitfalls as well as the importance of molecular work-up of PEComas because of important therapeutic consequences.

[Complexity of PEComas : Diagnostic approach, molecular background, clinical management (German version)]. / Komplexität von PEComen : Diagnose, Molekulargenetik, klinisches Management.

Perivascular epithelioid cell neoplasms (PEComas) are a family of mesenchymal neoplasms with features of both melanotic and smooth muscle differentiation. PEComa morphology is highly variable and encompasses epithelioid to spindle cells often with clear cytoplasm and prominent nucleoli. Molecularly, most PEComas are defined by a loss of function of the TSC1/TSC2 complex. Additionally, a distinct small subset of PEComas harboring rearrangements of the TFE3 (Xp11) gene locus has been identified. By presenting a series of three case reports with distinct features, we demonstrate diagnostic pitfalls as well as the importance of molecular work-up of PEComas because of important therapeutic consequences.

Comparing perfusion CT evaluation algorithms for predicting outcome after endovascular treatment in anterior circulation ischaemic stroke.

AIM: To analyse perfusion CT (PCT) evaluation algorithms for their predictive value for outcome after endovascular therapy (ET) in acute ischaemic stroke. MATERIALS AND METHODS: Twenty-six patients were prospectively enrolled to undergo endovascular therapy for moderate to severe [National Institute of Health Stroke Scale (NIHSS) score of ≥5] anterior circulation stroke ≤6 h of onset. PCT datasets were evaluated according to three algorithms: visual mismatch estimate (VME), Alberta Stroke Programme Early CT Score (ASPECTS) perfusion, and quantitative perfusion ratios (QPRs: RCBF, RCBV) of cerebral blood flow (CBF) and volume (CBV). Results were correlated with outcome measures [NIHSS score at discharge, NIHSS score change until discharge (ΔNIHSSA/D), mRS at 90 days (mRS90d)] and compared with a matched control group. RESULTS: Recanalization was achieved in 73%, median NIHSS score decreased from 14 to 5 at discharge. The treatment and control group did not differ by VME and ASPECTS perfusion, nor did VME correlate with any of the three outcome measures. ASPECTS perfusion was not predictive of any outcome measure in the ET group. RCBF and RCBV were associated with ΔNIHSSA/D in controls and, inversely, the ET group, but not with mRS90d. Receiver operating characteristic (ROC) analysis of RCBF (and RCBV) showed a positive predictive and negative predictive value of 87% (78%) and 74% (73%), respectively, for discriminating major neurological improvement (ΔNIHSSA/D <7 versus ≥7). CONCLUSIONS: Implementation of QPRs for CBF and CBV are superior to clinically used VME and ASPECTS perfusion evaluation methods for predicting early outcome after ET for anterior circulation stroke.

Feasibility of gadoxetate disodium-enhanced MR cholangiography in chronic cholestatic biliary disease.

AIM: To investigate the feasibility of gadoxetate disodium-enhanced magnetic resonance (MR) cholangiography in chronic obstructive cholestatic biliary disease in the clinical setting. MATERIALS AND METHODS: Twenty-three patients with dilated bile duct trees and ten volunteers underwent gadoxetate disodium-enhanced liver MR cholangiography and were enrolled in the present retrospective study. Gadoxetate disodium was given in a standardized manner as a bolus injection at a dose of 0.25 mmol/kg of body weight (0.1 ml/kg). Region of interest-based measurement of mean enhancement of the dilated bile ducts was performed in series before gadoxetate disodium administration and during hepatobiliary phases. RESULTS: Direct comparison of mean bile duct enhancement during hepatobiliary phases in the clinical imaging window between healthy volunteers [4.7 ± 2.2 arbitrary units (au)] and patients with dilated bile ducts (0.1 ± 0.3 au) revealed significantly lower or absent enhancement in dilated bile ducts (p = 0.001). CONCLUSION: Standard clinical gadoxetate disodium-enhanced MR cholangiography is not a reliable technique for the evaluation of the biliary trees, because of altered biliary gadoxetate disodium elimination in patients with chronic obstructive biliary diseases.

MR microscopy of the human finger and correlation with histology--a proof-of-principle study.

Magnetic resonance imaging (MRI) with small surface coils is a well established method for the diagnostic evaluation of finger masses. Until now, histological examination has been required to reliably assess tumor extent and infiltration of surrounding structures. Ultra-high-field MR microscopy (MRM) allows evaluation of anatomical structures and pathologies with submillimeter resolution. This study describes the diagnostic prospects and potential of MRM based on the ex-vivo examination of different finger pathologies. Ten human digits were examined by ex-vivo MRM at 7.1 Tesla (ClinScan, Bruker BioScan) using a T2-weighted turbo spin echo (TSE) sequence. Imaging parameters were: TE 48 ms; TR 8370 ms; slice thickness 700 µm; matrix size 1024 × 1024 pixels; FOV 37 × 37 mm; in-plane resolution 36 × 36 µm/voxel. Afterwards specimens were examined histologically. Histology and MRM were correlated. MRM allowed evaluation of the anatomy of the nail, the tendon insertions, the distal interphalangeal joint, and the neurovascular bundles. Finger abnormalities evaluated by MRM included osteomyelitis and metastatic disease. Subsequent histological examination confirmed MRM findings regarding origin, internal makeup, and extent of the structures visualized. This study demonstrates the potential of MRM for imaging small anatomical structures and pathologies of the human finger. Our ex-vivo findings correlate strongly with histology, suggesting that MRM may gain a central role in assessing anatomical structures and pathology in terms of morphology, extent, and infiltration of surrounding structures. Therefore, with increasing availability, MRM is expected to become an essential tool not only in experimental studies but also for daily routine.

Neurogenic heterotopic ossification: epidemiology and morphology on conventional radiographs in an early neurological rehabilitation population.

OBJECTIVE: To retrospectively evaluate neurogenic heterotopic ossification in an early neurological rehabilitation population (phases B and C) with respect to epidemiology and morphology on conventional radiographs. MATERIALS AND METHODS: Over a 4-year period, 1,463 patients treated at a clinic for early neurological rehabilitation were evaluated for clinical symptoms of neurogenic heterotopic ossification. In case of clinical suspicion, plain radiographs of the expected sites were obtained. If heterotopic ossification was detected, the initial and subsequent radiographs were retrospectively analyzed for sites, size, and morphology. Immature lesions were categorized as small (<10 mm) or large (10-100 mm). RESULTS: The prevalence rate of neurogenic heterotopic ossification was 2.05%. The condition was most common in young male adults. The hip was the most common site accounting for more than half of the cases. Two or more ossifications were seen in 56.7% of the affected patients with approximately two-thirds showing bilateral symmetric involvement of corresponding joint regions. The size of ossifications strongly varied interindividually. Small immature lesions demonstrated less progression in size than large lesions during maturation (P < 0.05). CONCLUSION: Standard radiographs, as a fast and inexpensive technique, allow the expected size progression of heterotopic ossifications during maturation to be estimated, which is relevant in terms of therapeutic decisions, patient mobilization, and neurological rehabilitation.

[Laser ablation. Do we still need it?]. / Laserablation. Brauchen wir sie noch?

Laser ablation (LA) is momentarily the only invasive ablation procedure besides radiofrequency ablation (RFA) which can be performed entirely under magnetic resonance imaging (MRI) guidance. The long-term outcome and morbidity profiles are broadly identical for both modalities, excluding the RFA-specific prevalence for skin burns. The technical and logistic disadvantages of LA have been overcome since the introduction of miniaturized two-component applicators. The main advantage of LA is its superior MRI compatibility. Interference-free imaging during LA allows MR thermometric real-time therapy control without the need for RF filters. High-resolution thermometry in the target zone only makes sense without the extinction artifact of a metal probe and this condition is met only by the glass fibers of LA. An independent therapy monitoring is crucial in modern scenarios of oncologic quality management.

CT-angiographic collateralization predicts final infarct volume after intra-arterial thrombolysis for acute anterior circulation ischemic stroke.

BACKGROUND: Final infarct volume after thrombolysis for acute ischemic stroke depends on time to, and degree of reperfusion and residual blood flow, which is influenced by leptomeningeal collateralization. We evaluated the role of collateralization in the ischemic territory as a predictor of infarct size. METHODS: Twenty-five patients (17 women, 8 men, mean age: 67.6 ± 12.4 years) selected by non-contrast-enhanced CT and CT angiography (CTA) underwent intra-arterial thrombolysis (iaT) within 6 h after symptom onset (mean 4.1 ± 1.3 h) for middle cerebral and terminal internal carotid artery (MCA/ICA) stroke. CTA was evaluated for collateralization using thick-slice coronal and axial maximum-intensity projection reconstructions according to a simple score, the CTA collateralization score (CTA-cs): 0 = no collateral filling, 1 = ≤50%, 2 = >50% but <100%, and 3 = 100% collateral filling. We analyzed the association between the final infarct volume on CT 5 days after the intervention and the CTA-cs, successful reperfusion (Thrombolysis in Myocardial Infarction, TIMI, grades 2 and 3) and time to treatment in a prospective study approved by our institutional review board, with informed consent from all patients. RESULTS: Reperfusion was achieved in 72%. Asymptomatic and symptomatic parenchymal hemorrhage occurred in 2 patients (8%) each and hemorrhagic transformation in 4 (16%). CTA-cs (r = -0.63; p < 0.001) and postinterventional TIMI grade (r = -0.403; p = 0.046) were inversely associated with final infarct volume. After multiple regression analysis, CTA-cs and reperfusion remained as independent predictors of final infarct volume whereas time to treatment and initial stroke severity did not. CONCLUSION: The extent of collateralization and reperfusion are independent predictors of final infarct volume in acute MCA/ICA stroke treated with iaT. Time to treatment and stroke severity had no independent effect on final infarct volume.

[MR microscopy of the human eye]. / MR-Mikroskopie des humanen Auges.

Ultra-high-field MR microscopy is a novel, non-invasive imaging technique to explore the strcutures of the human eye without optical distorsions. This review aims to provide an insight into the technique of the method. The normal MR microscopic anatomy of the human eye with correlations to histology is demonstrated. The use of MR microscopy in ther experimental ophthalmological setting is discussed.

Income is associated with hippocampal/amygdala and education with cingulate cortex grey matter volume.

Income and education are both elements of a person's socioeconomic status, which is predictive of a broad range of life outcomes. The brain's gray matter volume (GMV) is influenced by socioeconomic status and mediators related to an unhealthy life style. We here investigated two independent general population samples comprising 2838 participants (all investigated with the same MRI-scanner) with regard to the association of indicators of the socioeconomic status and gray matter volume. Voxel-based morphometry without prior hypotheses revealed that years of education were positively associated with GMV in the anterior cingulate cortex and net-equivalent income with gray matter volume in the hippocampus/amygdala region. Analyses of possible mediators (alcohol, cigarettes, body mass index (BMI), stress) revealed that the relationship between income and GMV in the hippocampus/amygdala region was partly mediated by self-reported stressors, and the association of years of education with GMV in the anterior cingulate cortex by BMI. These results corrected for whole brain effects (and therefore not restricted to certain brain areas) do now offer possibilities for more detailed hypotheses-driven approaches.

Physically active life style is associated with increased grey matter brain volume in a medial parieto-frontal network.

To examine the association between the amount of sports activity performed during leisure time and gray matter volume (GMV) of the brain we investigated differences in GMV in a large cohort study of community-dwelling older adults. 967 individuals indicated their average weekly sports activity via a questionnaire, and underwent high resolution T1-weighted structural imaging of the brain. We used voxel based morphometry (CAT 12) in a region of interest approach for (1) comparing participants with higher versus lower sports activity (median split) and (2) calculating a linear regression on GMV and sports activity. We carefully corrected for other factors known to have an impact on GMV (sex, age, total brain volume, education, cigarettes and alcohol consumption, body mass index) and excluded pathology (history of psychiatric or neurological disease; visual inspection of brain scans). Those participants who spend more time performing sports activity per week (median split with > 1 h/week) showed higher GMV in the dorsomedial frontal lobe, the superior parietal lobe, and the precuneus/cuneus area. When splitting participants by their median (55.5 years) into two groups we found a stronger protective effect of sports against age related GMV decline for the older part of the cohort. Overall, a more active lifestyle was associated with increased GMV in areas associated with self-awareness and working memory. These cohort data support data on the protective role of sports activity for the GMV.

Acute upper gastrointestinal hemorrhage: is a radiological interventional approach an alternative to emergency surgery?

The aim of our study was to discuss the option of endovascular treatment compared to surgery for patients with endoscopically unmanageable nonvariceal hemorrhage of the upper gastrointestinal tract. From 2000 to 2006, 23 patients (male, 15 male; female, 8; mean age, 69 years) who failed endoscopic therapy for upper gastrointestinal hemorrhage were retrospectively evaluated. Twelve patients were operated on (SG), whereas 11 patients had an endovascular intervention (IG). Technical and primary clinical success rates and complications rates were calculated. Clinical parameters and comorbidities were related to outcome. The surgical group suffered less frequently from pre-existing pulmonary diseases (SG, 17%; IG, 55%; p = 0.05) and had a higher incidence of shock requiring catecholamines (p < 0.01) or plasma expander therapy (p < 0.01). There was no significant difference in the incidence of recurrent bleeding episodes (SG, 17%; IG, 27%; p = 0.35) and mortality rates (SG, 17%; IG, 27%, p = 0.35). Deaths in the IG were due to recurrent bleeding. In patients with unsuccessful endoscopic control of nonvariceal bleeding of the upper GI tract, surgery remains a very effective treatment. However, in patients with a high surgical risk due to unknown bleeding sources and/or severe pre-existing diseases/comorbidities, endovascular therapy offers an excellent treatment option. These patients should then be operated on as early as possible to minimize the risk of recurrent bleeding episodes, which are associated with high morbidity and mortality.

[Teleradiology and mammography screening: evaluation of a network with dedicated workstations for reporting]. / Teleradiologie im Mammographie-Screening: Evaluation eines Testnetzes mit dedizierten Befundungsstationen.

PURPOSE: Evaluation of a system that supports a workflow for breast cancer screening by mammography. The time of installation, system reliability and workstation operation were evaluated. MATERIALS AND METHODS: The evaluated system (Image Diagnost, Munich, Germany) contains 2 diagnostic mammography workstations, a centralized server, and 2 Dicom shuttles for exchanging images via a physically existing network structure. Temporary archiving is possible. A mask designed for the needs of mammography screening facilitates assignment of BIRADS categories. The system automatically compares the categories assigned by a first and second reviewer and decides whether a consensus conference should be held. In the event that a conference is needed, the reviews are transmitted to the mammography expert responsible for the screening program and the consensus conference. Images are transferred via ISDN, Germany's National Research and Education Network (in the following DFN) and a central server between 2 sites which are approx. 100 km apart. We evaluated the duration of installation, the reliability of the system, and the usability of the workstation. Since we used curative mammography for evaluating the system, the patient age was noted for comparison. RESULTS: The system was installed in five days. Once installed, the system functioned without any major breakdowns. Mammography units of 2 manufacturers were able to be connected to the system without difficulty. Mammographies of 151 patients were exchanged between the sites and evaluated by 2 radiologists. 57 % of the patients were in the screening age (50-69 years). 9 exams were classified BIRADS 4a, 2 were 4b and 3 were BIRADS 5. The evaluations were technically perfect in 146/151 cases; hanging protocols had to be altered manually in 6 cases; the window/level had to be manually adjusted in 26/151 cases. Magnification was sufficient in all cases. The system exchanges examinations extremely quickly; up to 100 mammography exams may be evaluated in 1 hr. CONCLUSION: The system supports the workflow given by the German Mammography Screening program both locally and in a network.

Subinternship in Radiology - A Practical Start to the Specialization?

Purpose: To identify factors influencing medical students to choose radiology in the four-month clinical elective in the final year of medical school following radiology subinternships. Materials and Methods: A subsample of medical students in a nationwide German online survey evaluated a subinternship in radiology (19 items). They were divided into four groups: Students who could imagine doing a clinical elective in radiology in the practical year based on their experiences during the subinternship ("yes, based on subinternship"), students who could not ("no, based on subinternship") and students who had made this decision prior to the subinternship ("yes, prior to subinternship" and "no, prior to subinternship"). Results: 94 medical students evaluated a radiology subinternship (54.4 % females). Based on their experiences during the subinternship, 54 students (57.4 %) intended to do a final year clinical elective in radiology, 39 of them (41.5 %) being encouraged by the subinternship. 40 (42.6 %) reported having a negative attitude towards a clinical elective in radiology, 16 of them (17.0 %) having made this decision based on their subinternship experience. Groups did not differ regarding gender (p = 0.396) and age (p = 0.853). Students motivated to do a final year clinical elective in radiology experienced excellent academic teaching (p = 0.001) and practical involvement (p = 0.003), achieved their learning goals more often (p = 0.001), were better integrated into the team (p = 0.001), and acquired more practical skills (p = 0.003). Overall satisfaction was higher in these groups (p = 0.001). Conclusion: Satisfaction with a radiology subinternship is crucial for motivating medical students to do a final year clinical elective in radiology. A structured subinternship and continuous mentoring should be targeted to keep students connected to radiology. Key Points: • Radiology subinternships influence further interest in the specialization.• The quality and structure of teaching critically influence student satisfaction.• Team integration and practical involvement positively affect the attitude towards a specialization. Citation Format: • Kasch R, Wirkner J, Hosten N et al. Subinternship in Radiology - A Practical Start to the Specialization? Fortschr Röntgenstr 2016; 188: 1024 - 1030.

Population-Based Imaging and Radiomics: Rationale and Perspective of the German National Cohort MRI Study.

UNLABELLED: The MRI study within the German National Cohort, a large-scale, population-based, longitudinal study in Germany, comprises comprehensive characterization and phenotyping of a total of 30 000 participants using 3-Tesla whole-body MR imaging. A multi-centric study design was established together with dedicated core facilities for e. g. managing incidental findings or providing quality assurance. As such, the study represents a unique opportunity to substantially impact imaging-based risk stratification leading to personalized and precision medicine. Supported by the developments in the field of computational science, the newly developing scientific field of radiomics has large potential for the future. In the present article we provide an overview on population-based imaging and Radiomics and conceptualize the rationale and design of the MRI study within the German National Cohort. KEY POINTS: • Population-based imaging and Radiomics constitute two emerging fields with great oppertunities and challenges for Radiology.• As part of the MRI-study of the NAKO approximately 30 000 subjects will undergo 3 Tesla whole-body MRI.• MR Imaging data is publicly accessable and will provide important insights into the natural history of disease processes and personalized risk profiles of the general population. Citation Format: • Schlett CL, Hendel T, Weckbach S et al. Population-Based Imaging and Radiomics: Rationale and Perspective of the German National Cohort MRI Study. Fortschr Röntgenstr 2016; 188: 652 - 661.

Advanced brain aging: relationship with epidemiologic and genetic risk factors, and overlap with Alzheimer disease atrophy patterns.

We systematically compared structural imaging patterns of advanced brain aging (ABA) in the general-population, herein defined as significant deviation from typical BA to those found in Alzheimer disease (AD). The hypothesis that ABA would show different patterns of structural change compared with those found in AD was tested via advanced pattern analysis methods. In particular, magnetic resonance images of 2705 participants from the Study of Health in Pomerania (aged 20-90 years) were analyzed using an index that captures aging atrophy patterns (Spatial Pattern of Atrophy for Recognition of BA (SPARE-BA)), and an index previously shown to capture atrophy patterns found in clinical AD (Spatial Patterns of Abnormality for Recognition of Early Alzheimer's Disease (SPARE-AD)). We studied the association between these indices and risk factors, including an AD polygenic risk score. Finally, we compared the ABA-associated atrophy with typical AD-like patterns. We observed that SPARE-BA had significant association with: smoking (P<0.05), anti-hypertensive (P<0.05), anti-diabetic drug use (men P<0.05, women P=0.06) and waist circumference for the male cohort (P<0.05), after adjusting for age. Subjects with ABA had spatially extensive gray matter loss in the frontal, parietal and temporal lobes (false-discovery-rate-corrected q<0.001). ABA patterns of atrophy were partially overlapping with, but notably deviating from those typically found in AD. Subjects with ABA had higher SPARE-AD values; largely due to the partial spatial overlap of associated patterns in temporal regions. The AD polygenic risk score was significantly associated with SPARE-AD but not with SPARE-BA. Our findings suggest that ABA is likely characterized by pathophysiologic mechanisms that are distinct from, or only partially overlapping with those of AD.

Intestinal fluid volumes and transit of dosage forms as assessed by magnetic resonance imaging.

AIM: The gastrointestinal transit of sequentially administered capsules was investigated in relation to the availability of fluid along the intestinal lumen by magnetic resonance imaging. METHODS: Water-sensitive magnetic resonance imaging was performed on 12 healthy subjects during fasting and 1 h after a meal. Specifiable non-disintegrating capsules were administered at 7, 4 and 1 h prior to imaging. RESULTS: While food intake reduced the mean fluid volumes in the small intestine (105 +/- 72 mL vs. 54 +/- 41 mL, P < 0.01) it had no significant effect on the mean fluid volumes in the colon (13 +/- 12 mL vs. 18 +/- 26 mL). The mean number of separated fluid pockets increased in both organs after meal (small intestine: 4 vs. 6, P < 0.05; large intestine: 4 vs. 6, P < 0.05). The distribution of capsules between the small and large intestine was strongly influenced by food (colon: 3 vs. 17 capsules, P < 0.01). CONCLUSIONS: The results show that fluid is not homogeneously distributed along the gut, which likely contributes to the individual variability of drug absorption. Furthermore, transport of fluid and solids through the ileocaecal valve is obviously initiated by a meal-induced gastro-ileocaecal reflex.

[No detectable nephrotoxic side effect using a dimer, non-ionic contrast media in cerebral perfusion computed tomography in case of suspected brain ischemia]. / Keine nachweisbare Nephrotoxizität eines dimeren nichtionischen Röntgenkontrastmittels bei der notfallmässigen kraniellen Perfusions-Computertomographie.

PURPOSE: In suspected brain ischemia, the perfusion cerebral computed tomography (cCT) should be performed with the lowest amount of contrast media to avoid a contrast media induced nephropathy (CIN) even if the patient already is in renal failure. We were interested to find the best parameters for this examination. MATERIAL AND METHODS: From February 2000 to March 2003, 138 patients (58 females, 80 males, mean age 66.8 years) underwent cCT-perfusion immediately after the admission to our stroke unit. Of these patients, 62% (n = 86) had normal renal function and 38% (n = 52) renal failure (up to 381 micromol/l basic serum creatinine). We varied volume (20-80 ml), flow (5 vs. 7.2 ml/s) and concentration (270 vs. 320 ml/mg iodine) of a dimer, non-ionic contrast media (Visipaque) to establish 5 groups. So we got patients receiving 6 g, 12 g, 16 g, 19 g and 25 g of iodine. After generating the perfusion maps, two radiologists reviewed the quality of the maps and scored it (1-5). We measured the serum creatinine before contrast application and at follow up cCT (days 3 and 7). RESULTS: The quality of the maps increases with increasing amount of iodine. However, the diagnostic result was not significantly better using more than about 16 g of iodine (e. g., 60 ml--7.2 ml/s--270 mg/ml) in cCT-perfusion studies. Only one patient had a pathologic increase in serum creatinine (day 1: 93; day 4: 146 micromol/l) but died at day 5 because of massive co-morbidity and septic pneumonia. No CIN occurred even in the patient group with pre-existent renal failure. CONCLUSIONS: About 60 ml contrast media and a moderate flow rate of about 7 ml/s ensure good results in perfusion-cCT, even if the patients have poor blood circulation or arteriosclerosis. The use of a dimer, non-ionic contrast media (range of 6-25 g iodine) seems to minimize the risk of CIN in the daily routine.

[Laser-induced thermotherapy (LITT) of tumors of the liver in central location: results and complications]. / Laserinduzierte Thermotherapie (LITT) von Lebertumoren in zentraler Lokalisation: Ergebnisse und Komplikationen.

PURPOSE: To investigate whether laser-induced thermotherapy (LITT) for tumors of the liver in central location is a sufficient and safe therapeutic option. MATERIAL AND METHODS: According to predefined criteria, 23 of 136 patients were chosen to be treated with LITT because of malignant liver tumors. At the time of the first LITT, the patients had 28 central tumors (27 metastases, one HCC), which were treated in 34 sessions with 64 laser applications and had a clinical and imaging follow-up every 3 months. RESULTS: The primary effectiveness rate was 74.1% and the secondary effectiveness rate 82.1%. The mortality rate was 0%. Major complications occurred in one patient (hemorrhagic pleural effusion), while minor complications occurred in 10 patients. During the median follow-up of 20 months (range 3-57 months), local tumor progression developed in 22% of the tumors. The effectiveness rate was 78.6%, 71.4% and 64.3% after 3, 6 and 9 months. The median survival was 46.0 months (95% confidence interval: 28.6-47.1 months). CONCLUSION: In our patients, complications and ablation rate of laser-induced thermotherapy for central liver tumors do not differ from those in peripheral location as described in the literature.