Zusammenfassung Ziel: Effizienz der Strahlenschutzmittel bez?glich der Augenlinsendosis des Untersuchers bei fluoroskopischen Interventionen. Material und Methoden: Ein Patientenphantom wurde an einer DSA-Anlage exponiert. Dosismessungen erfolgten mittels Ionisationskammer in Augenposition des Untersuchers. Die Messungen imitierten fluoroskopische Interventionen, wobei die Reduktion der Streustrahlung durch den tischmontierten Strahlenschutz (Untertisch-Vorhang und ?bertisch-Aufsatz) beurteilt wurde. Die Effizienz der deckenmontierten Bleiacrylglasscheibe wurde im Streustrahlungsfeld eines Quaderphantoms bestimmt. Die Schutzwirkung verschiedener Bleiglasbrillen und Bleiacrylglasvisiere wurde durch Thermolumineszenzdosimetrie an einem Kopfphantom in Direktstrahlung evaluiert. Ergebnisse: Die Exposition der Linse bei radiologischen Untersuchungen von ca. 110???550??Sv wird durch den Untertisch-Vorhang nur gering reduziert. Durch Vorhang plus Aufsatz kann die Linsendosis bei Interventionen am Abdomen in PA-Projektion etwa um den Faktor 2 reduziert werden. In?25?-LAO ergibt sich ein Reduktionsfaktor zwischen 1,2 und 5. Die AP-Projektion ergibt die h?chsten Dosiswerte, auch ist die Wirkung des tischmontierten Strahlenschutzes minimal. Die deckenmontierte Bleiacrylglasscheibe reduziert die Linsendosis bei optimaler Positionierung etwa um den Faktor 30.?Die Bleiglasbrillen und -visiere reduzieren die Linsendosis maximal um den Faktor 8???10. Je?nach Design der untersuchten Modelle ist die Schutzwirkung geringer, insbesondere f?r Strahlungen am Kopfphantom aus laterokaudaler Richtung. Teils werden sogar Erh?hungen der Linsendosis durch die Visiere beobachtet. Schlussfolgerung: Die Exposition der Augenlinse kann bei konsequenter Anwendung der Strahlenschutzmittel auch unterhalb der neuen Grenzwerte der ICRP gehalten werden.
Purpose To investigate contrast dynamics and artifacts associated with different breathing maneuvers during pulmonary computed tomography angiography (pCTA) in a prospective randomized clinical trial. Method Three different breathing maneuvers (inspiration, expiration, Mueller) were randomly assigned to 146 patients receiving pCTA for suspected pulmonary embolism (PE). Contrast enhancement of central and peripheral arteries and imaging quality of lung parenchyma were compared and analyzed. Results were compared by using the analysis of variances (ANOVA) and Kruskal-Wallis-Test. Results Mean enhancement in the pulmonary trunk was highest during breath-hold in inspiration (293 HU, range 195–460 HU) compared to Mueller (259 HU, range 136–429 HU, p = 0022) and expiration (267 HU, range 115–376 HU). This was similar for the right pulmonary artery (inspiration 289 HU, range 173–454 HU; Mueller 250 HU, range 119–378 HU; p = 0.007; expiration 257 HU, range 114–366 HU; p = 0.032) and left pulmonary artery (inspiration 280.3 HU, range 170–462 HU; Mueller 245 HU, range 111–371 HU; p = 0.016; expiration 252 HU, range 110–371 HU). Delineation of peripheral arteries was significantly better in inspiration vs Mueller (p = 0.006) and expiration (p = 0.049). Assessment of the lung parenchyma was significantly better in inspiration vs Mueller (p = 0.013) or expiration (p < 0.001). Conclusions Resting inspiratory position achieved the highest enhancement levels in central and peripheral pulmonary arteries and best image quality of the pulmonary parenchyma in comparison to other breathing maneuvers. It is necessary to train the maneuver prior to the examination in order to avoid deep inspiration with the risk of suboptimal opacification of the pulmonary arteries.
The aim of this study was to evaluate whether a 3-dimensional (3D) camera can outperform highly trained technicians in precision of patient positioning and whether this transforms into a reduction in patient exposure. Materials and Methods: In a single-center study, 3118 patients underwent computer tomography (CT) scans of the chest and/or abdomen on a latest generation single-source CT scanner supported with an automated patient positioning system by 3D camera. One thousand five hundred fifty-seven patients were positioned laser-guided by a highly trained radiographer (camera off ) and 1561 patients with 3D camera (camera on) guidance. Radiation parameters such as effective dose, organ doses, CT dose index, and dose length product were analyzed and compared. Isocenter accuracy and table height were evaluated between the 2 groups. Results: Isocenter positioning was significantly improved with the 3D camera (P < 0.001) as compared with visual laser-guided positioning. Absolute table height differed significantly (P < 0.001), being higher with camera positioning (165.6 ± 16.2 mm) as compared with laser-guided positioning (170.0 ± 20.4 mm). Radiation exposure decreased using the 3D camera as indicated by dose length product (321.1 ± 266.6 mGy•cm; camera off: 342.0 ± 280.7 mGy•cm; P = 0.033), effective dose (3.3 ± 2.7 mSv; camera off: 3.5 ± 2.9; P = 0.053), and CT dose index (6.4 ± 4.3 mGy; camera off: 6.8 ± 4.6 mGy; P = 0.011). Exposure of radiation-sensitive organs such as colon (P = 0.015) and red bone marrow (P = 0.049) were also lower using the camera. Conclusions: The introduction of a 3D camera improves patient positioning in the isocenter of the scanner, which results in a lower and also better balanced dose reduction for the patients.
HER2-targeted therapy is currently the subject of several studies in lung cancer and other solid tumors using either tyrosine kinase inhibitors (TKI) or targeted-antibody–drug conjugates. We describe a 61-year-old female patient with HER2 mutated adenocarcinoma of the lungs who received chemo-immunotherapy, followed by trastuzumab deruxtecan (T-DXd) and third-line Ramucirumab/Docetaxel at disease progression. Plasma ctDNA monitoring was obtained at 12 timepoints during therapy and revealed HER2 mutation allele frequencies that corresponded to the clinical course of disease. HER2-targeted T-DXd therapy resulted in a profound clinical response and may be an option for NSCLC patients carrying an activated HER2 mutation. Longitudinal liquid biopsy quantification of the underlying driver alteration can serve as a powerful diagnostic tool to monitor course of therapy.
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