Diagnostische Genauigkeit und Dosisreduktion vaskulärer und perkutaner Interventionen mittels periinterventioneller Cone Beam Computertomographie (CBCT)

Jede Intervention lässt sich in die Schritte Visualisierung des Ziels, Navigation und Therapie unterteilen. Durch die Entwicklung neuer periinterventioneller, bildgebender Verfahren wie der Cone Beam Computertomographie (CBCT) besteht die Möglichkeit, dreidimensionale Schnittbilddatensätze mit isotropen Voxeln unmittelbar während einer Intervention zu akquirieren. Dieses Verfahren eröffnet somit neue Möglichkeiten für die Detektion von Zielstrukturen und Gefäßen. Die weitere Verarbeitung der Daten mit semiautomatisierten Softwaretools kann entscheidend zum Therapieerfolg beitragen. Wie bei jedem neuen bildgebenden Verfahren müssen entsprechende Untersuchungsprotokolle in der klinischen Routine in Bezug auf ihre Grenzen und ihre Dosiseffizienz getestet werden. In der vorliegenden Schrift wurden 6 Arbeiten zusammengefasst, welche die erarbeiteten Untersuchungsprotokolle in Hinblick auf die Möglichkeit der Tumor- und Gefäßdetektion sowie deren Dosiseffizienz evaluieren. Dafür wurden in der 1. Originalarbeit retrospektiv bei 28 Patienten mit insgesamt 85 hypervaskularisierten, hepatozellulären Karzinomen die Tumordetektionsrate eines neuen, einphasigen Splitbolus-Kontrastmittelprotokolls mit der präinterventionellen MRT in der arteriellen sowie hepatobiliären Kontrastmittelphase verglichen. Im CBCT ließen sich in einer qualitativen Untersuchung mit zwei Readern signifikant mehr Tumore im Vergleich zum MRT in der arteriellen Phase detektieren (121 vs. 94 / 170). Es konnte auch gezeigt werden, dass das periinterventionelle CBCT vergleichbar viele HCC-Manifestationen identifizieren kann wie das MRT in der hepatobiliären Kontrastmittelphase. Dabei zeigte sich in der quantitativen Analyse, dass der intrinsische Bildkontrast des CBCTs deutlich höher ist als im MRT (arterielles MRT: 0,11; hepatobiläres MRT:0,13; CBCT: 0,97, p < 0,001). Das Kontrast-zu- Rausch-Verhältnis ist dabei im MRT nicht signifikant höher als im CBCT (arterielles MRT: 7,79; hepatobiläres MRT: 8,58; CBCT: 4,43, p = 0,157). Basierend auf den Ergebnissen der ersten Studie wurde das Splitbolusprotokoll für die Detektion von hypervaskularisierten Tumoren optimiert. Die 2. Originalarbeit untersuchte retrospektiv an 20 konsekutiv therapierten Patienten mit 77 hypovaskularisierten Tumormanifestationen die Detektionsrate des modifizierten CBCT- Splitbolusprotokolls im Vergleich zur DSA. Es zeigte sich das 90% der Zieltumore im CBCT sichtbar waren, wohingegen in der konventionellen DSA lediglich 37,5% der Zielmanifestationen dargestellt werden konnten. Bezogen auf die Kontrast-zu-Rausch und intrinsischen Kontrastverhältnisse im Vergleich zur präintervenitonellen MRT konnten die Ergebnisse der 1. Originalarbeit auch für diese Tumorentitäten bestätigt werden. Das CBCT kann potentiell zu einer zusätzlichen Strahlenexposition bei TACE-Therapien führen. Daher wurden in der 3. Originalarbeit retrospektiv 140, in der klinischen Routine untersuchte, Patienten (70 Patienten mit CBCT- und 70 mit DSA-Navigation) in Hinblick auf die zusätzliche Strahlenbelastung durch das CBCT untersucht. Der Anteil des CBCTs an der Gesamtdosis betrug 6%. Aus einem CBCT-Datensatz kann jedoch der komplette Gefäßbaum extrahiert und der Fluoroskopie überlagert werden. Die Durchführung der CBCTs führte in der Studie im Durchschnitt zu einer Erhöhung des Gesamtdosisflächenproduktes um ca. 2%, jedoch besteht das Potential durch wegfallende DSA-Untersuchungen und konsequente Nutzung des 3D-Overlays die Gesamtdosis um bis zu 46% zu reduzieren. Das Konzept zur Erkennung der Zielgefäße wurde in der 4. Originalarbeit auf die Prostataarterienembolisation (n = 22) übertragen. Da diese Intervention mit einer vergleichsweise hohen Strahlenexposition für Patient und Personal verbunden ist, ist eine schnelle Detektion der versorgenden Gefäße bei sehr variabler Anatomie im kleinen Becken und benigner Grunderkrankung von hoher Relevanz. Dabei konnte gezeigt werden, dass der Versorgungstyp im CBCT signifikant besser bestimmt werden konnte als in der selektiven DSA über die A.iliaca int. (p = 0,047). Während im CBCT alle Prostataarterien korrekt erkannt werden konnten, wurden in der DSA 18% (links) bzw. 17% (rechts) der Arterien nicht identifiziert. Der Dosisanteil des CBCTs an der Gesamtintervention lag erneut bei 6%, jener der DSA bei 84%. Somit kann das CBCT zu einer sicheren Detektion der Zielarterien sowie auch hier zu einer potentiellen Dosisreduktion beitragen. Daraufhin wurde der Einsatz des CBCT zur Führung transjugulärer Pfortaderpunktionen im Rahmen von 21 TIPSS-Anlagen (5. Originalarbeit) evaluiert. Eine CBCT-Gruppe wurde mit einer sonographisch geführten Vergleichsgruppe prospektiv (n = 15) sowie mit einem historischen Kollektiv mit alleiniger fluoroskopischer Navigation (n = 23) retrospektiv verglichen. Dabei konnte der transjuguläre Zugang zur Pfortader, wenn auch statistisch nicht signifikant, jedoch mit einer geringeren Anzahl an Punktionsversuchen im Vergleich zur Ultraschall-Kontrollgruppe (CBCT: 2, Ultraschall: 4) und einer niedrigeren Punktionszeit (32 ± 45min vs. 36 ± 45min) bei etwas längeren Interventionszeiten (CBCT 115 ± 52min, Ultraschall: 112 ± 41min, Fluoroskopie: 110 ± 33 min) erreicht werden. Die Strahlenexposition im CBCT war mit 563 ± 289 Gy*cm2 gegenüber der Ultraschall- (322 ± 186 Gy*cm2) und der Fluoroskopiegruppe mit 469 ± 352 Gy*cm2 und einem Dosisanteil von ca. 4% nicht signifikant erhöht (p = 0,069). Somit konnte gezeigt werden, dass TIPSS-Anlagen in CBCT-Navigation sicher möglich sind. Bei vergleichbarer Anzahl an Punktionen, Interventionsdauer sowie Strahlenexposition steht somit eine weitere Methode für komplexe TIPSS-Prozeduren zur Verfügung. In der 6. Originalarbeit wurden CBCT-gesteuerte, perkutane Pfortaderpunktionen im Rahmen von 20 Pfortaderembolisationen retrospektiv bewertet und mit einer sonographisch geführten Kontrollgruppe verglichen (CBCT: 10, Ultraschall: 10 Patienten). Unter CBCT-Führung konnte nach 3,1 ± 2,5 Punktionen ein sicherer perkutaner Zugang zur Pfortader hergestellt werden. Jedoch zeigte sich im Vergleich zur sonographischen Kontrollgruppe eine signifikant längere Interventionszeit (61 ± 27 min vs. 41,6 ± 15,2 min, p = 0,04) bei nicht signifikant höherer Strahlenexposition (CBCT: 288.060 ± 154.383 mGy*cm2 vs. 178.501 ± 115.221 mGy*cm2, p = 0,12), während der Dosisanteil des CBCTs bei 6% lag. Daraus lässt sich schließen, dass CBCT-gestützte perkutane Pfortaderpunktionen sicher möglich sind und insbesondere bei Patienten mit schlechten Schallbedingungen eine Alternative zur bisherigen Punktionsmethode darstellen können. Die Ergebnisse dieser Arbeit müssen jedoch bei der Übertragung auf neuere Angiographieanlagen entsprechend überprüft und ggf. angepasst werden. Zusammenfassend lässt sich feststellen, dass die CBCT eine große Bereicherung für vaskuläre Interventionen, insbesondere in Hinblick auf die Präzision der Eingriffe, darstellt. Sie bietet dabei ein großes Potential zur Dosisreduktion. Des weiteren kann die CBCT-Navigation auch für Punktionen beweglicher Zielstrukturen eine sichere Alternative darstellen, wenn herkömmliche Methoden an ihre Grenzen stoßen

Diagnostic Value of Initial Chest CT Findings for the Need of ICU Treatment/Intubation in Patients with COVID-19

Computed tomography (CT) plays an important role in the diagnosis of COVID-19. The aim of this study was to evaluate a simple, semi-quantitative method that can be used for identifying patients in need of subsequent intensive care unit (ICU) treatment and intubation. We retrospectively analyzed the initial CT scans of 28 patients who tested positive for SARS-CoV-2 at our Level-I center. The extent of lung involvement on CT was classified both subjectively and with a simple semi-quantitative method measuring the affected area at three lung levels. Competing risks Cox regression was used to identify factors associated with the time to ICU admission and intubation. Their potential diagnostic ability was assessed with receiver operating characteristic (ROC)/area under the ROC curves (AUC) analysis. A 10% increase in the affected lung parenchyma area increased the instantaneous risk of intubation (hazard ratio (HR) = 2.00) and the instantaneous risk of ICU admission (HR 1.73). The semi-quantitative measurement outperformed the subjective assessment diagnostic ability (AUC = 85.6% for ICU treatment, 71.9% for intubation). This simple measurement of the involved lung area in initial CT scans of COVID-19 patients may allow early identification of patients in need of ICU treatment/intubation and thus help make optimal use of limited ICU/ventilation resources in hospitals

CT-Based Risk Stratification for Intensive Care Need and Survival in COVID-19 Patients—A Simple Solution

We evaluated a simple semi-quantitative (SSQ) method for determining pulmonary involvement in computed tomography (CT) scans of COVID-19 patients. The extent of lung involvement in the first available CT was assessed with the SSQ method and subjectively. We identified risk factors for the need of invasive ventilation, intensive care unit (ICU) admission and for time to death after infection. Additionally, the diagnostic performance of both methods was evaluated. With the SSQ method, a 10% increase in the affected lung area was found to significantly increase the risk for need of ICU treatment with an odds ratio (OR) of 1.68 and for invasive ventilation with an OR of 1.35. Male sex, age, and pre-existing chronic lung disease were also associated with higher risks. A larger affected lung area was associated with a higher instantaneous risk of dying (hazard ratio (HR) of 1.11) independently of other risk factors. SSQ measurement was slightly superior to the subjective approach with an AUC of 73.5% for need of ICU treatment and 72.7% for invasive ventilation. SSQ assessment of the affected lung in the first available CT scans of COVID-19 patients may support early identification of those with higher risks for need of ICU treatment, invasive ventilation, or death

Yttrium-90 radioembolization for unresectable hepatocellular carcinoma: predictive modeling strategies to anticipate tumor response and improve patient selection

Objectives: This study aims to better characterize potential responders of Y-90-radioembolization at baseline through analysis of clinical variables and contrast enhanced (CE) MRI tumor volumetry in order to adjust therapeutic regimens early on and to improve treatment outcomes. Methods: Fifty-eight HCC patients who underwent Y-90-radioembolization at our center between 10/2008 and 02/2017 were retrospectively included. Pre- and post-treatment target lesion volumes were measured as total tumor volume (TTV) and enhancing tumor volume (ETV). Survival analysis was performed with Cox regression models to evaluate 65% ETV reduction as surrogate endpoint for treatment efficacy. Univariable and multivariable logistic regression analyses were used to evaluate the combination of baseline clinical variables and tumor volumetry as predictors of >= 65% ETV reduction. Results: Mean patients' age was 66 (SD 8.7) years, and 12 were female (21%). Sixty-seven percent of patients suffered from liver cirrhosis. Median survival was 11 months. A threshold of >= 65% in ETV reduction allowed for a significant (p = 0.04) separation of the survival curves with a median survival of 11 months in non-responders and 17 months in responders. Administered activity per tumor volume did predict neither survival nor ETV reduction. A baseline ETV/TTV ratio greater than 50% was the most important predictor of arterial devascularization (odds ratio 6.3) in a statistically significant (p = 0.001) multivariable logistic regression model. The effect size was strong with a Cohen's f of 0.89. Conclusion: We present a novel approach to identify promising candidates for Y-90 radioembolization at pre-treatment baseline MRI using tumor volumetry and clinical baseline variables

A prospective randomized controlled trial assessing the effect of music on patients’ anxiety in venous catheter placement procedures

The aim of the study was to assess the influence of music on anxiety levels compared to standard patient care in patients undergoing venous catheter placement procedures. This prospective randomized controlled trial included patients undergoing placement procedures for peripherally inserted central venous catheters (PICC), ports and central venous catheters (CVC). Patients were randomly assigned to a music intervention group (MIG) and a control group (CTRL). State and trait anxiety levels were assessed as primary outcome using the state-trait anxiety inventory (STAI) before and after the procedures. Secondary outcomes comprised averaged heart rate for all participants and time of radiological surveillance for port placement procedures exclusively. 72 participants were included into the final analysis (MIG n = 40; CTRL n = 32). All procedures were successful and no major complications were reported. Mean levels for post-interventional anxieties were significantly lower in the MIG compared to the CTRL (34.9 +/- 8.9 vs. 44 +/- 12.1; p < 0.001). Mean heart rate in the MIG was significantly lower than in the CTRL (76.1 +/- 13.7 vs. 93 +/- 8.9; p < 0.001). Procedure time for port implantation was significantly longer in the MIG by 3 min 45 s (p = 0.031). Music exposure during central venous catheter placement procedures highly significantly reduces anxiety and stress levels and can be used to improve patients' overall experience in the angio suite

Liver Venous Deprivation (LVD) Versus Portal Vein Embolization (PVE) Alone Prior to Extended Hepatectomy: A Matched Pair Analysis

Background: To investigate whether liver venous deprivation (LVD) as simultaneous, portal vein (PVE) and right hepatic vein embolization offers advantages in terms of hypertrophy induction before extended hepatectomy in non-cirrhotic liver. Materials and Methods: Between June 2018 and August 2019, 20 patients were recruited for a prospective, nonrandomized study to investigate the efficacy of LVD. After screening of 134 patients treated using PVE alone from January 2015 to August 2019, 14 directly matched pairs regarding tumor entity (cholangiocarcinoma, CC and colorectal carcinoma, CRC) and hypertrophy time (defined as time from embolization to follow-up imaging) were identified. In both treatment groups, the same experienced reader (> 5 years experience) performed imaging-based measurement of the volumes of liver segments of the future liver remnant (FLR) prior to embolization and after the standard clinical hypertrophy interval ( similar to 30 days), before surgery. Percentage growth of segments was calculated and compared. Results: After matched follow-up periods (mean of 30.5 days), there were no statistically significant differences in relative hypertrophy of FLRs. Mean +/- standard deviation relative hypertrophy rates for LVD/PVE were 59 +/- 29.6%/54.1 +/- 27.6% (p = 0.637) for segments II + III and 48.2 +/- 22.2%/44.9 +/- 28.9% (p = 0.719) for segments II-IV, respectively. Conclusions: LVD had no significant advantages over the standard method (PVE alone) in terms of hypertrophy induction of the FLR before extended hepatectomy in this study population

Hepatocellular carcinoma tumor thrombus entering the right atrium treated with combining percutaneous and intravenous high-dose-rate brachytherapy: a case report

The presented report describes a case of a Hepatocellular carcinoma (HCC) tumor thrombus (TT) infiltrating the inferior vena cava (IVC) and the right atrium (RA) in a 66-year old male patient who initially presented with TT related symptoms. CT-guided high-dose-rate brachytherapy (HDRBT) was performed for both, the intraparenchymal primary and the TT. A marked improvement of the tumor-related symptoms and shrinkage of the tumor mass were achieved six months after treatment initiation. The combination of intravascular and percutaneous HDRBT demonstrating a promising approach to palliate tumor-related symptoms in advanced HCC with macrovascular invasion

Low impact of regular PCR testing on presence at work site during the COVID-19 pandemic: experiences during an open observational study in Lower Saxony 2020-21

Background: Since social distancing during the COVID-19-pandemic had a profound impact on professional life, this study investigated the effect of PCR testing on on-site work. Methods: PCR screening, antibody testing, and questionnaires offered to 4,890 working adults in Lower Saxony were accompanied by data collection on demographics, family status, comorbidities, social situation, health-related behavior, and the number of work-related contacts. Relative risks (RR) with 95 % confidence intervals were estimated for the associations between regular PCR testing and other work and health-related variables, respectively, and working on-site. Analyses were stratified by the suitability of work tasks for mobile office. Results: Between April 2020 and February 2021, 1,643 employees underwent PCR testing. Whether mobile working was possible strongly influenced the work behavior. Persons whose work was suitable for mobile office (mobile workers) had a lower probability of working on-site than persons whose work was not suitable for mobile office (RR = 0.09 (95 % CI: 0.07 – 0.12)). In mobile workers, regular PCR-testing was slightly associated with working on-site (RR = 1.19 (0.66; 2.14)). In those whose working place was unsuitable for mobile office, the corresponding RR was 0.94 (0.80; 1.09). Compared to persons without chronic diseases, chronically ill persons worked less often on-site if their workplace was suitable for mobile office (RR = 0.73 (0.40; 1.33)), but even more often if their workplace was not suitable for mobile office (RR = 1.17 (1.04; 1.33)). Conclusion: If work was suitable for mobile office, regular PCR-testing did not have a strong effect on presence at the work site. Trial registration: An ethics vote of the responsible medical association (Lower Saxony, Germany) retrospectively approved the evaluation of the collected subject data in a pseudonymized form in the context of medical studies (No. Bo/30/2020; Bo/31/2020; Bo/32/2020)

Mobile SARS‑CoV‑2 screening facilities for rapid deployment and university-based diagnostic laboratory

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic has created a public crisis. Many medical and public institutions and businesses went into isolation in response to the pandemic. Because SARS-CoV-2 can spread irrespective of a patient's course of disease, these institutions’ continued operation or reopening based on the assessment and control of virus spread can be supported by targeted population screening. For this purpose, virus testing in the form of polymerase chain reaction (PCR) analysis and antibody detection in blood can be central. Mobile SARS-CoV-2 screening facilities with a built-in biosafety level (BSL)-2 laboratory were set up to allow the testing offer to be brought close to the subject group's workplace. University staff members, their expertise, and already available equipment were used to implement and operate the screening facilities and a certified diagnostic laboratory. This operation also included specimen collection, transport, PCR and antibody analysis, and informing subjects as well as public health departments. Screening facilities were established at different locations such as educational institutions, nursing homes, and companies providing critical supply chains for health care. Less than 4 weeks after the first imposed lockdown in Germany, a first mobile testing station was established featuring a build-in laboratory with two similar stations commencing operation until June 2020. During the 15-month project period, approximately 33,000 PCR tests and close to 7000 antibody detection tests were collected and analyzed. The presented approach describes the required procedures that enabled the screening facilities and laboratories to collect and process several hundred specimens each day under difficult conditions. This report can assist others in establishing similar setups for pandemic scenarios

Fluid preinjection for microwave ablation in an ex vivo bovine liver model assessed with volumetry in an open MRI system

PURPOSEWe aimed to detect possible differences in microwave ablation (MWA) volumes after different fluid preinjections using magnetic resonance imaging (MRI).MATERIALS AND METHODSMWA volumes were created in 50 cuboid ex vivo bovine liver specimens (five series: control [no injection], 10 mL water, 10 mL 0.9% NaCl, 10 mL 6% NaCl, and 10 mL 12% NaCl preinjections; n=10 for each series). The operating frequency (915 megahertz), ablation time (7 min), and energy supply (45 watts) were constant. Following MWA, two MR sequences were acquired, and MR volumetry was performed for each sequence.RESULTSFor both sequences, fluid preinjection did not lead to significant differences in MWA ablation volumes compared to the respective control group (sequence 1: mean MWA volumes ranged from 7.0±1.2 mm [water] to 7.8±1.3 mm [12% NaCl] vs. 7.3±2.1 mm in the control group; sequence 2: mean MWA volumes ranged from 4.9±1.4 mm [12% NaCl] to 5.5±1.9 mm [0.9% NaCl] vs. 4.7±1.6 mm in the control group). The ablation volumes visualized with the two sequences differed significantly in general (P < 0.001) and between the respective groups (control, P ≤ 0.001; water, P < 0.001; 0.9% NaCl, P < 0.001; 6% NaCl, P ≤ 0.001; 12% NaCl, P < 0.001). The volumes determined with sequence 1 were closer to the expected ablation volume of 8 mL compared to those determined with sequence 2.CONCLUSIONFor the fluid qualities and concentrations assessed, there is no evidence that fluid preinjection results in larger coagulation volumes after MWA. Because ablation volumes determined by MRI vary with the sequence used, interventionalists should gain experience in how to interpret postinterventional imaging findings (with the MR scanner, sequences, and parameters used) to accurately estimate the outcome of the interventions they perform