M Pech

First experiences with intravenous port systems authorized for high pressure injection of contrast agent in multiphasic computed tomography

PURPOSE The aim of this prospective study was to examine two port systems for intravenous chemotherapy, authorized for high pressure injection, with respect to implantation, complications, implementation, and patency. MATERIALS AND METHODS 40 high pressure port systems of the two available models (20 x Power Port [Bard], 20 x T-Port-Contrast [PFM]) and 20 standard port systems (X-Port [BARD]) as the control group were implanted. Both high pressure systems are authorized for injection with a maximum pressure of 300 PSI. The patient population was comprised of patients with different malignomas and liver metastases. At regular intervals following the protocol of the chemotherapy, multiphasic CT for tumor staging was carried out. RESULTS The intravenous port systems were implanted without complications under sonographic guidance with transjugular access. The mean implantation time was 30 min (range: 22 - 40 min). After a median follow-up time of 6 months, the port patency was 100%. No port infections and no complications during high pressure injection of contrast agent occurred during this period. The level of contrast measured in the aorta was equivalent to the level of contrast in the vessels when contrast agent is administered over a large peripheral intravenous access. CONCLUSION The intravenous high pressure port systems are equivalent to standard systems with regard to implantation and implementation. Intravenous chemotherapy can be performed as usual. The advantage is the possibility of multiphasic CT with authorized flow rates of up to 5 ml/sec.

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 ± 3.8 mm; HRG 23.6 ± 2.5 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 ± 18.0%; HRG 25.3 ± 17.5%; 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 ± 0.7 mm; HRG 3.8 ± 0.9 mm; p = 0.004). In contrast, the number of lumbar arteries (LAs; LRG 2.7 ± 1.4; HRG 3.6 ± 1.2; univariate: p = 0.01; multivariate: p = 0.006) as well as their diameter (LRG 2.1 ± 0.4 mm; HRG 2.4 ± 0.4 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.

CT-gesteuerte Brachytherapie

Ziel:Analyse der Sicherheit und Effektivität CT-gesteuerter Brachytherapie zur Ablation von Lebermalignomen.Patienten und Methodik:21 Patienten mit 21 Lebermalignomen (19 Metastasen, zwei primäre Lebermalignome) wurden mit perkutaner, CT-gesteuerter interstitieller Brachytherapie mit 192Ir behandelt. Alle Patienten wiesen Umstände auf, die eine bildgeführte thermische Ablation mit Radiofrequenz oder laserinduzierter Thermotherapie (LITT) einschränkten: Tumordurchmesser ≥ 5 cm bei sieben, enge Lagebeziehung zu Pfortader oder großen Lebervenen bei zehn, enge Lagebeziehung zur Hepatikusgabel bei vier Patienten. Die Dosimetrie erfolgte über unmittelbar nach CT-geführter Applikatorpositionierung akquirierte dreidimensionale CT-Datensätze.Ergebnisse:Die mittlere Tumorgröße betrug 4,6 cm (2,5–11 cm). Die minimale Dosis innerhalb des Tumorvolumens lag im Mittel bei 17 Gy (12–20 Gy). Der Volumenanteil gesunden Leberparenchyms mit einer Exposition > 5 Gy betrug 18% (5–39%) vom Lebergesamtvolumen abzüglich Tumorlast. Übelkeit und Erbrechen traten bei sechs Patienten auf (28%). Ein Patient entwickelte eine Obstruktion des Ductus choledochus durch ein strahleninduziertes Tumorödem in unmittelbarer Nachbarschaft. Leberenzymparameter und Bilirubinwerte zeigten regelhaft diskrete Anstiege ohne klinisches Korrelat. Die lokale Tumorkontrolle betrug 87% nach 6 Monaten und 70% nach 12 Monaten.Schlussfolgerung:CT-gesteuerte Brachytherapie ist sicher und effektiv. Die Technik ermöglicht gegenüber thermischen Ablationsverfahren eine breitere Indikationsstellung hinsichtlich Tumorgröße und Tumorlokalisation.Purpose:To assess safety and efficacy of CT-guided brachytherapy of liver malignancies.Patients and Methods:21 patients with 21 liver malignancies (19 metastases, two primary liver tumors) were treated with interstitial CT-guided brachytherapy applying a 192Ir source. In all patients, the use of image-guided thermal tumor ablation such as by radiofrequency or laser-induced thermotherapy (LITT) was impeded either by tumor size ≥ 5 cm in seven, adjacent portal or hepatic vein in ten, or adjacent bile duct bifurcation in four patients. Dosimetry was performed using three-dimensional CT data sets acquired after CT-guided positioning of the brachytherapy catheters.Results:The mean tumor diameter was 4.6 cm (2.5–11 cm). The mean minimal tumor dose inside the tumor margin amounted to 17 Gy (12–20 Gy). The proportion of the liver parenchyma exposed to > 5 Gy was 18% (5–39%) of total liver parenchyma minus tumor volume. Nausea and vomiting were observed in six patients after brachytherapy (28%). One patient demonstrated obstructive jaundice due to tumor edema after irradiation of a metastasis adjacent to the bile duct bifurcation. We commonly encountered asymptomatic increases of liver enzymes. Local control rates after 6 and 12 months were 87% and 70%, respectively.Conclusion:CT-guided brachytherapy is safe and effective. This technique displays broader indications compared to image-guided thermal ablation by radiofrequency or LITT with respect to tumor size or localization.