[Radiation-induced cataract-an occult risk for urologists]. / Strahleninduzierter Katarakt ­ ein okkultes Berufsrisiko für Urologen.

BACKGROUND: Radiation-induced cataracts represent a relevant risk to people occupationally exposed to radiation. The annual limit dose for the eye lens was reduced to 20 mSv per year by German legislation (radiation protect law StrlSchG 2017; 2013/59/Euratom) based on recommendation of International Commission on Radiation Protection (2011 ICRP) to avoid radiation-induced cataracts. OBJECTIVES: Is there a risk of exceeding the annual limit dose for the eye lens in routine urological practice without special radiation protection for the head? METHODS: As part of a prospective, monocentric dosimetry study, of 542 different urological, fluoroscopically guided interventions, the eye lens dose was determined using a forehead dosimeter (thermo-luminescence dosemeter TLD, Chipstrate) over a period of 5 months. RESULTS: An average head dose of 0.05 mSv per intervention (max. 0.29 mSv) was found with an average dose area product of 485.33 Gy/cm2. Significant influencing factors for a higher dose were a higher patient body mass index (BMI), a longer operation time, and a higher dose area product. The level of experience of the surgeon showed no significant influence. DISCUSSION: With 400 procedures per year or an average of 2 procedures per working day, the critical annual limit value for the eye lenses or for the risk of radiation-induced cataract would be exceeded without special protective measures. CONCLUSION: Consistently effective radiation protection of the eye lens is essential for daily work in uroradiological interventions. This may require further technical developments.

Older People Facing the Crisis of COVID-19: Between Fragility and Resilience.

The health crisis we are facing is challenging seniors' resources and capacities for adaptation and resilience. The PACOVID survey, set up a few days after containment, investigates their psychological and social experiences with regard to the COVID-19 crisis and to what extent these characteristics, representations and attitudes have an impact on health and mortality. A telephone survey is being carried out on 935 people already followed up in the framework of ongoing epidemiological studies. As we are writing this article, the interviews conducted during the containment have just ended. Even though we will have to wait for the analysis of the results to draw conclusions, words collected by the psychologists during the interviews already illustrate a great heterogeneity in the way older adults lived this experience: social isolation, anxiety, the importance of family and the difficulty of being deprived of it, but also remarkable coping skills and resilience capacities.

Cytokine levels in children and adults with wheezing and asthma show specific patterns of variability over time.

Levels of cytokines are used for in-depth characterization of patients with asthma; however, the variability over time might be a critical confounder. To analyze the course of serum cytokines in children, adolescents and adults with asthma and in healthy controls and to propose statistical methods to control for seasonal effects. Of 532 screened subjects, 514 (91·5%) were included in the All Age Asthma Cohort (ALLIANCE). The cohort included 279 children with either recurrent wheezing bronchitis (more than two episodes) or doctor-diagnosed asthma, 75 healthy controls, 150 adult asthmatics and 31 adult healthy controls. Blood samples were collected and 25 µl serum was used for analysis with the Bio-Plex Pr human cytokine 27-Plex assay. Mean age, body mass index and gender in the three groups of wheezers, asthmatic children and adult asthmatics were comparable to healthy controls. Wheezers (34·5%), asthmatic children (78·7%) and adult asthmatics (62·8%) were significantly more often sensitized compared to controls (4·5, 22 and 22·6%, respectively). Considering the entire cohort, interleukin (IL)-1ra, IL-4, IL-9, IL-17, macrophage inflammatory protein (MIP)-1- α and tumor necrosis factor (TNF)- α showed seasonal variability, whereas IL-1ß, IL-7, IL-8, IL-13, eotaxin, granulocyte colony-stimulating factor (G-CSF), interferon gamma-induced protein (IP)-10, MIP-1 ß and platelet-derived growth factor (PDGF)-BB did not. Significant differences between wheezers/asthmatics and healthy controls were observed for IL-17 and PDGF-BB, which remained stable after adjustment for the seasonality of IL-17. Seasonality has a significant impact on serum cytokine levels in patients with asthma. Because endotyping has achieved clinical importance to guide individualized patient-tailored therapy, it is important to account for seasonal effects.

Prospective evaluation of CT-guided HDR brachytherapy as a local ablative treatment for renal masses: a single-arm pilot trial.

PURPOSE: In this pilot trial, we investigate the safety of CT-guided high-dose-rate brachytherapy (HDR-BT) as a local ablative treatment for renal masses not eligible for resection or nephrectomy. METHODS: We investigated renal function after irradiation by HDR-BT in 16 patients (11 male, 5 female, mean age 76 years) with 20 renal lesions (renal cell carcinoma n = 18; renal metastases n = 2). Two patients had previous contralateral nephrectomy and two had ipsilateral partial nephrectomy. Six lesions had a hilar localization with proximity to the renal pelvis and would have not been favorable for thermal ablation. Renal function loss was determined within 1 year after HDR-BT by renal scintigraphy and laboratory parameters. Further investigations included CT and MRI every 3 months to observe procedural safety and local tumor control. Renal function tests were analyzed by Wilcoxon's signed rank test with Bonferroni-Holm correction of p-values. Survival and local tumor control underwent a Kaplan-Meier estimation. RESULTS: Median follow-up was 22.5 months. One patient required permanent hemodialysis 32 months after repeated HDR-BT and contralateral radiofrequency ablation of multifocal renal cell carcinoma. No other patient developed a significant worsening in global renal function and no gastrointestinal or urogenital side effects were observed. Only one patient died of renal tumor progression. Local control rate was 95% including repeated HDR-BT of two recurrences. CONCLUSION: HDR-BT is a feasible and safe technique for the local ablation of renal masses. A phase II study is recruiting to evaluate the efficacy of this novel local ablative treatment in a larger study population.

[Small renal cell carcinoma-active surveillance and ablation]. / Kleines Nierenzellkarzinom ­ Aktive Überwachung und Ablation.

The incidence of renal cell carcinoma has been rising for years. At the same time there is an increasing prevalence of chronic renal failure with subsequent higher morbidity and shorter life expectancy in those affected. In the last decades the gold standard has thus shifted from radical to partial nephrectomy or tumor enucleation. A treatment alternative can be advantageous for selected patients with high morbidity and an increased risk of complications in anesthesia or surgery. Active surveillance represents a controlled delay in the initiation of treatment with a curative intention. Percutaneous radiofrequency ablation and laparoscopic cryoablation are currently the most commonly used treatment alternatives. Newer ablation procedures, such as high-intensity focused ultrasound, irreversible electroporation, microwave ablation, stereotactic ablative radiotherapy and high-dose brachytherapy have a high potential in some cases but are still considered experimental for the treatment.

Upper-Urinary-Tract Effects After Irreversible Electroporation (IRE) of Human Localised Renal-Cell Carcinoma (RCC) in the IRENE Pilot Phase 2a Ablate-and-Resect Study.

PURPOSE: Irreversible electroporation (IRE) is a new potential ablation modality for small renal masses. Animal experiments have shown preservation of the urine-collecting system (UCS). The purpose of this clinical study was to perform the first evaluation and comparison of IRE's effects on the renal UCS by using urinary cytology, magnetic-resonance imaging, and resection histology in men after IRE of pT1a renal-cell carcinoma (RCC). METHODS: Seven patients with biopsy-proven RCC pT1a cN0cM0 underwent IRE in a phase 2a pilot ablate-and-resect study (IRENE trial). A contrast-enhanced, diffusion-weighted MRI and urinary cytology was performed 1 day before and 2, 7, and 27 days after IRE. Twenty-eight days after IRE the tumour region was completely resected surgically. RESULTS: Technical feasibility was demonstrated in all patients. In all cases, MRI revealed complete coverage of the tumour area by the ablation zone with degenerative change. The urographic late venous MRI phase (urogram scans) demonstrated normal morphological appearances. Urine cytology showed a temporary vacuolisation of the cyto- and caryoplasmas after IRE. Whereas the urothelium showed signs of regeneration 28 days after IRE-ablation, the tumour and parenchyma below it showed necrosis and permanent tissue destruction. CONCLUSIONS: Renal percutaneous IRE appears to be a safe treatment for pT1a RCC. The preservation of the UCS with unaltered normal morphology as well as urothelial regeneration and a phenomenon (new in urinary cytology) of temporary degeneration with vacuolisation of detached transitional epithelium cells were demonstrated in this clinical pilot study.

[Recurrent pain and swelling of the left leg in a 49-year-old male patient]. / Rezidivierende Beinschwellungen und Schmerzen im linken Bein bei einem 49-jährigen Patienten.

A 49-year-old male patient presented due to recurrent pain and swelling in the left leg. The patient had had deep venous thrombosis with pulmonary embolism 5 years previously. Since then, he had been treated with Vit-k-antagonists. Pronounced paraumbilical collateral circulation of unknown origin was striking. Doppler sonographic evaluation pointed to May-Thurner syndrome. This was confirmed by phlebography. Venous stenting of the stenosis in the left iliac vein achieved long-term symptom improvement. This case report is intended to draw attention to the rare May-Thurner syndrome as an important differential diagnosis of deep vein thrombosis and, at the same time, identify diagnostic and therapeutic treatment strategies.

[Prostate gland - what would urologists like to know from radiologists?] / Die Vorsteherdrüse ­ was möchte der Urologe vom Radiologen wissen?

A more than 100-year period, where the prostate was only seen and treated as a whole is coming to an end right now. Finally, high resolution imaging is providing deep insights and detailed information so that new therapeutic procedures can aim for the smallest targets within the gland. The long-standing wish of patients for individual noninvasive diagnostics and treatment of prostate diseases can now be fulfilled by providing new tailored concepts; however, in order to transfer the enormous amount of new information into the specific clinical patient situation, a closely knit interdisciplinary approach is required. In this setting, the traditional outpatient consultation service is overstretched in every aspect. It is now the time for new innovative constructs. The current one-sided service concept for urologists, radiologists and radiation therapists is therefore behind the times and the development of a "prostate management team" with equally cooperating partners from each specialty is the task for the future.

Radioablation of adrenal gland malignomas with interstitial high-dose-rate brachytherapy : Efficacy and outcome.

PURPOSE: To assess the efficacy, safety, and outcome of image-guided high-dose-rate (HDR) brachytherapy in patients with adrenal gland metastases (AGM). MATERIALS AND METHODS: From January 2007 to April 2014, 37 patients (7 female, 30 male; mean age 66.8 years, range 41.5-82.5 years) with AGM from different primary tumors were treated with CT-guided HDR interstitial brachytherapy (iBT). Primary endpoint was local tumor control (LTC). Secondary endpoints were time to untreatable progression (TTUP), time to progression (TTP), overall survival (OS), and safety. In a secondary analysis, risk factors with an influence on survival were identified. RESULTS: The median biological equivalent dose (BED) was 37.4 Gy. Mean LTC after 12 months was 88%; after 24 months this was 74%. According to CTCAE criteria, one grade 3 adverse event occurred. Median OS after first diagnosis of AGM was 18.3 months. Median OS, TTUP, and TTP after iBT treatment were 11.4, 6.6, and 3.5 months, respectively. Uni- and multivariate Cox regression analyses revealed significant influences of synchronous disease, tumor diameter, and the total number of lesions on OS or TTUP or both. CONCLUSION: Image-guided HDR-iBT is safe and effective. Treatment- and primary tumor-independent features influenced survival of patients with AGM after HDR-iBR treatment.

Olfactory Response and Host Plant Feeding of the Central American Locust Schistocerca piceifrons piceifrons Walker to Common Plants in a Gregarious Zone.

The Central American locust (CAL) Schistocerca piceifrons piceifrons Walker is one of the most harmful plant pests in the Yucatan Peninsula, where an important gregarious zone is located. The olfactory response and host plant acceptance by the CAL have not been studied in detail thus far. In this work, the olfactory response of the CAL to odor of various plant species was evaluated using an olfactometer test system. In addition, the host plant acceptance was assessed by the consumption of leaf area. Results showed that the CAL was highly attracted to odor of Pisonia aculeata. Evaluation of host plant acceptance showed that the CAL fed on Leucaena glauca and Waltheria americana, but not on P. aculeata or Guazuma ulmifolia. Analysis of leaf thickness, and leaf content of nitrogen (N) and carbon (C) showed that the CAL was attracted to plant species with low leaf C content.

A prospective Phase 2a pilot study investigating focal percutaneous irreversible electroporation (IRE) ablation by NanoKnife in patients with localised renal cell carcinoma (RCC) with delayed interval tumour resection (IRENE trial).

INTRODUCTION: Focal ablation therapy is playing an increasing role in oncology and may reduce the toxicity of current surgical treatments while achieving adequate oncological benefit. Irreversible electroporation (IRE) has been proposed to be tissue-selective with potential advantages compared with current thermal-ablation technologies or radiotherapy. The aim of this pilot trial is to determine the effectiveness and feasibility of focal percutaneous IRE in patients with localised renal cell cancer as a uro-oncological tumour model. METHODS: Prospective, monocentric Phase 2a pilot study following current recommendations, including those of the International Working Group on Image-Guided Tumor Ablation. Twenty patients with kidney tumour (T1aN0M0) will be recruited. This sample permits an appropriate evaluation of the feasibility and effectiveness of image-guided percutaneous IRE ablation of locally confined kidney tumours as well as functional outcomes. Percutaneous biopsy for histopathology will be performed before IRE, with magnetic-resonance imaging one day before and 2, 7, 27 and 112 days after IRE; at 28 days after IRE the tumour region will be completely resected and analysed by ultra-thin-layer histology. DISCUSSION: The IRENE study will investigate over a short-term observation period (by magnetic-resonance imaging, post-resection histology and assessment of technical feasibility) whether focal IRE, as a new ablation procedure for soft tissue, is feasible as a percutaneous, tissue-sparing method for complete ablation and cure of localised kidney tumours. Results from the kidney-tumour model can provide guidance for designing an effectiveness and feasibility trial to assess this new ablative technology, particularly in uro-oncology.

[Arterial and portal venous complications after HPB surgical procedures: Interdisciplinary management]. / Arterielle und portalvenöse Gefäßkomplikationen nach HBP-Eingriffen : Interdisziplinäres Management.

The surgical treatment of hepatopancreatobiliary (HPB) diseases requires complex operative procedures. Within the last decades the morbidity (36-50 %) and mortality (<5 %) of these procedures could be reduced; nonetheless, postoperative complications still occur in 41.2 % of cases. Compared with hepatobiliary procedures, pancreatic surgery shows an increased rate of complications. Postoperative bleeding has a major effect on the outcome and the incidence is 6.7 % after pancreatic surgery and 3.2 % after hepatobiliary surgery. The major causes of early postoperative hemorrhage are related to technical difficulties in surgery whereas late onset postoperative hemorrhage is linked to anastomosis insufficiency, formation of fistulae or abscesses due to vascular arrosion or formation of pseudoaneurysms. In many cases, delayed hemorrhage is preceded by a self-limiting sentinel bleeding. The treatment is dependent on the point in time, location and severity of the hemorrhage. The majority of early postoperative hemorrhages require surgical treatment. Late onset hemorrhage in hemodynamically stable patients is preferably treated by radiological interventions. After interventional hemostatic therapy 8.2 % of patients require secondary procedures. In the case of hemodynamic instability or development of sepsis, a relaparotomy is necessary. The treatment concept includes surgical or interventional remediation of the underlying cause of the hemorrhage. Other causes of postoperative morbidity and mortality are arterial and portal venous stenosis and thrombosis. Following liver resection, thrombosis of the portal vein occurs in 8.5-9.1 % and in 11.6 % following pancreatic resection with vascular involvement. Interventional surgical procedures or conservative treatment are suitable therapeutic options depending on the time of diagnosis and clinical symptoms. The risk of morbidity and mortality after HPB surgery can be reduced only in close interdisciplinary cooperation, which is particularly true for vascular complications.

Assessment and monitoring of liver function by ¹³C-aminopyrine breath test after selective transarterial chemoembolisation of hepatocellular carcinoma.

BACKGROUND: Liver function and tumor staging are essential parameters for selection of treatment modalities in patients with hepatocellular carcinoma (HCC). Transarterial chemoembolization (TACE) is associated with a risk of deterioration of liver function. In clinical routine hepatic function in patients with liver cirrhosis is assessed by the Child-Pugh-classification. Dynamic breath tests allow the assessment of the hepatic functional mass and have the potential to give more accurate information on hepatic function periinterventionally. PATIENTS AND METHODS: A prospective clinical study was performed in 13 patients receiving a total of 18 TACE sessions. (13)C-aminopyrine breath test was performed the day before TACE, 2 days and 30 days after TACE and correlated with standard laboratory work-up of the patients. RESULTS: Fourteen TACE sessions were performed in Child A liver cirrhosis, 4 in Child B cirrhosis. All patients presented with impaired aminopyrine metabolism at baseline. No significant changes in the (13)C aminopyrine breath test following TACE were observed. Two patients treated in Child A cirrhosis decompensated to Child B, one of them recovered. No further decompensation was observed in patients treated in Child B cirrhosis. DISCUSSION AND CONCLUSION: Liver function assessment with (13)C-aminopyrine breath test and Child-Pugh-classification following TACE was discordant in a large proportion of patients. Whether a quantification of mitochondrial liver function in patients planned to undergo locoregional treatment of HCC in liver cirrhosis is helpful in the prediction of postprocedural liver decompensation needs to be addressed in larger prospective clinical trials.

Identification of predictive CT angiographic factors in the development of high-risk type 2 endoleaks after endovascular aneurysm repair in patients with infrarenal aortic aneurysms.

PURPOSE: An extensive analysis of the value of computed tomography (CT) parameters as potential predictors of the clinical outcome of type 2 endoleaks after endovascular aortic aneurysm repair (EVAR). MATERIALS AND METHODS: Initial CT scans of 130 patients with abdominal aortic aneurysms (AAAs) were retrospectively reviewed. On the basis of postoperative CT scans and angiographies, patients were stratified into a low-risk group (LRG; without or transient type 2 endoleak; n = 80) and a high-risk group (HRG, persistent type 2 endoleak or need for reintervention; n = 50). Statistical analysis comprised a univariate and multivariate analysis. RESULTS: Anatomical, thrombus-specific, as well as aortic side branch parameters were assessed on the initial CT scan. Of all anatomical parameters, the diameter of the immediate infrarenal aorta was significantly different in the univariate analysis (LRG 22.4 ±â€Š3.8 mm; HRG 23.6 ±â€Š2.5 mm; p = 0.03). The investigation of the thrombus-specific parameters showed a trend towards statistical significance for the relative thrombus load (LRG 31.7 ±â€Š18.0%; HRG 25.3 ±â€Š17.5%; p = 0.09). Assessment of aortic side branches revealed only for the univariate analysis significant differences in the patency of the inferior mesenteric artery (LRG 71.3%; HRG 92.0%; p = 0.003) and their diameter (LRG 3.3 ±â€Š0.7 mm; HRG 3.8 ±â€Š0.9 mm; p = 0.004). In contrast, the number of lumbar arteries (LAs; LRG 2.7 ±â€Š1.4; HRG 3.6 ±â€Š1.2; univariate: p = 0.01; multivariate: p = 0.006) as well as their diameter (LRG 2.1 ±â€Š0.4 mm; HRG 2.4 ±â€Š0.4 mm; univariate: p < 0.001; multivariate: p = 0.006) were highly significantly associated with the development of type 2 endoleaks of the HRG. CONCLUSION: The most important predictive factors for the development of high-risk type 2 endoleaks were mainly the number and the diameter of the LAs which perfused the AAA. KEY POINTS: • This study is a very detailed and comprehensive analysis of the value of various CT parameters as potential predictors of the clinical outcome of type 2 endoleaks after EVAR. • Anatomical as well as thrombus-specific parameters were unsuitable as predictors. • The most important predictive factors were mainly the number and the diameter of the LAs which perfused the AAA.

[Differential Vascular Medical Management of Visceral Artery Aneurysms in a Single-Centre Consecutive Patient Cohort as Part of an Ongoing Disease-Specific Systematic Clinical Prospective Observational Study]. / Differenzielles gefäßmedizinisches Management des Viszeralarterienaneurysmas anhand einer unizentrischen konsekutiven Patientenkohorte im Rahmen einer laufenden krankheitsspezifischen, klinisch-systematischen, prospektiven Observationsstudie.

AIM, PATIENTS AND METHODS: By means of a systematic single-centre prospective observational study, spectrum (symptomatology, frequency) and diagnostics of the different visceral artery aneurysm sites as well as the postinterventional course of the various therapeutic options used according to local finding and patient's clinical status as well as risk factors were analysed to contrast the different procedures (conservative, image-guided radiological intervention, open vascular surgery) in consideration of their decision-making criteria and their early postinterventional outcome (on the basis of complication rate, peri-interventional morbidity and hospital lethality) including relevant references from the literature. RESULTS: During a time period of 14 years, 22 patients (sex ratio: 12 males/10 females; mean age: 54.3 [range: 22-76] years) were registered. Most frequently, visceral artery aneurysms occurred in the splenic artery (50 %). The gastroduodenal artery, the hepatic artery and the right renal artery were affected in each with 13.6 % (n = 3/22), the superior mesenteric artery in 9.1 % (n = 2/22). The majority of patients (54.5 %) were treated with image-guided radiological intervention, whereas in 31.8 %, the patient underwent open vascular surgery and 13.6 % of cases were managed with "watchful waiting". While morbidity was 21.1 % (n = 4/19), overall lethality was 9.1 % (n = 2/22). CONCLUSION: Decision-making for a specific therapeutic approach should be made (i) after adequate diagnostic measures (transabdominal ultrasound, MR angiography, duplex ultrasonography, CT-A/DSA if required), (ii) on an individual case-adapted base, (iii) in a vascular surgical centre, (iv) case-associated to the specific local finding (in particular, according to size/specific probability of rupture [cave: gravidity]) and (v) according to the individual risk profile using the whole spectrum of therapeutic options (conservative vs. interventional; image-guided radiological intervention [endovascular repair such as embolisation, stent or stent graft] vs. open vascular surgery [according to a step-up approach]; open vascular ligation vs. reconstruction after exclusion of the aneurysm) including sufficient quality assurance of the treatment results as well as control investigations (duplex ultrasonography; MR-A if required) in a specialised vascular surgical out-patient centre within appropriate time intervals.

[What does the visceral surgeon need to know about computed tomography in the diagnostic work-up of the acute abdomen?]. / Was muss der Viszeralchirurg über den Einsatz der Computertomografie in der Abklärung des akuten Abdomens wissen.

The acute abdomen is a very serious yet common condition of patients presenting in the emergency department. The clinical symptoms of patients with acute abdomen are often unspecific. The responsibility of the surgeon in charge is to differentiate acute life-threatening from less serious conditions with a high level of diagnostic accuracy in a minimal period of time. Imaging represents a cornerstone in the diagnostic work-up of patients with acute abdomen. Computed tomography (CT) is increasingly utilised to detect emergency conditions in patients with acute abdomen. In this review article we aim to elaborate the role of CT in the imaging strategy for acute abdomen in comparison to conventional radiography, ultrasonography and magnetic resonance imaging. In addition, relevant factors pertaining for the indication of CT such as exposure to ionising radiation and safety of iodinated contrast media are discussed.

Can early computed tomography angiography after endovascular aortic aneurysm repair predict the need for reintervention in patients with type II endoleak?

PURPOSE: This study was designed to identify parameters on CT angiography (CTA) of type II endoleaks following endovascular aortic aneurysm repair (EVAR) for abdominal aortic aneurysm (AAA), which can be used to predict the subsequent need for reinterventions. METHODS: We retrospectively identified 62 patients with type II endoleak who underwent early CTA in mean 3.7 ± 1.9 days after EVAR. On the basis of follow-up examinations (mean follow-up period 911 days; range, 373-1,987 days), patients were stratified into two groups: those who did (n = 18) and those who did not (n = 44) require reintervention. CTA characteristics, such as AAA, endoleak, as well as nidus dimensions, patency of the inferior mesenteric artery, number of aortic branch vessels, and the pattern of endoleak appearance, were recorded and correlated with the clinical outcome. RESULTS: Univariate and receiver operating characteristic curve regression analyses revealed significant differences between the two groups for the endoleak volume (surveillance group: 1391.6 ± 1427.9 mm(3); reintervention group: 3227.7 ± 2693.8 mm(3); cutoff value of 2,386 mm(3); p = 0.002), the endoleak diameter (13.6 ± 4.3 mm compared with 25.9 ± 9.6 mm; cutoff value of 19 mm; p < 0.0001), the number of aortic branch vessels (2.9 ± 1.2 compared with 4.2 ± 1.4 vessels; p = 0.001), as well as a "complex type" endoleak pattern (13.6 %, n = 6 compared with 44.4 %, n = 8; p = 0.02). CONCLUSIONS: Early CTA can predict the future need for reintervention in patients with type II endoleak. Therefore, treatment decision should be based not only on aneurysm enlargement alone but also on other imaging characteristics.

Prospective Evaluation of the radiologist's hand dose in CT-guided interventions.

PURPOSE: Assessment of radiologist's hand dose in CT-guided interventions and determination of influencing factors. MATERIALS AND METHODS: The following CT-guided interventions were included: Core biopsy, drainage, periradicular therapy, and celiac plexus neurolysis. The hand dose was measured with an immediately readable dosimeter, the EDD-30 (Unfors, Sweden). The default parameters for CT fluoroscopy were 120 kV, 90 mA and a 4 mm slice thickness. All interventions were performed on a 16-slice CT unit (Aquilion 16 Toshiba, Japan). The tumor size, degree of difficulty (1 - 3), level of experience and device parameters (mAs, dose-length product, scan time) were documented. RESULTS: 138 CT-guided interventions (biopsy n = 99, drainage n = 23, pain therapy n = 16) at different locations (lung n = 41, retroperitoneum n = 53, liver n = 25, spine n = 19) were included. The lesion size was 4 - 240 mm (median: 23 mm). The fluoroscopy time per intervention was 4.6 - 140.2 s (median: 24.2 s). The measured hand dose ranged from 0.001 - 3.02 mSv (median: 0.22 mSv). The median hand dose for lung puncture (n = 41) was slightly higher (median: 0.32 mSv, p = 0.01) compared to that for the liver, retroperitoneum and other. Besides physical influencing factors, the degree of difficulty (p = 0.001) and summed puncture depth (p = 0.004) correlated significantly with the hand dose. CONCLUSION: The median hand dose for different CT-guided interventions was 0.22 mSv. Therefore, the annual hand dose limit would normally only be reached with about 2000 interventions.

Short- and mid-term effects of irreversible electroporation on normal renal tissue: an animal model.

PURPOSE: Irreversible electroporation (IRE) is a novel nonthermal tissue ablation technique by high current application leading to apoptosis without affecting extracellular matrix. Previous results of renal IRE shall be supplemented by functional MRI and differentiated histological analysis of renal parenchyma in a chronic treatment setting. METHODS: Three swine were treated with two to three multifocal percutaneous IRE of the right kidney. MRI was performed before, 30 min (immediate-term), 7 days (short-term), and 28 days (mid-term) after IRE. A statistical analysis of the lesion surrounded renal parenchyma intensities was made to analyze functional differences depending on renal part, side and posttreatment time. Histological follow-up of cortex and medulla was performed after 28 days. RESULTS: A total of eight ablations were created. MRI showed no collateral damage of surrounded tissue. The highest visual contrast between lesions and normal parenchyma was obtained by T2-HR-SPIR-TSE-w sequence of DCE-MRI. Ablation zones showed inhomogeneous necroses with small perifocal edema in the short-term and sharp delimitable scars in the mid-term. MRI showed no significant differences between adjoined renal parenchyma around ablations and parenchyma of untreated kidney. Histological analysis demonstrated complete destruction of cortical glomeruli and tubules, while collecting ducts, renal calyxes, and pelvis of medulla were preserved. Adjoined kidney parenchyma around IRE lesions showed no qualitative differences to normal parenchyma of untreated kidney. CONCLUSIONS: This porcine IRE study reveals a multifocal renal ablation, while protecting surrounded renal parenchyma and collecting system over a mid-term period. That offers prevention of renal function ablating centrally located or multifocal renal masses.