Benefit of Contrast-Enhanced Ultrasound (CEUS) in the Follow-Up Care of Patients with Colon Cancer: A Prospective Multicenter Study.

PURPOSE: According to the German guidelines on colorectal cancer, unenhanced ultrasound is recommended for follow-up. On the other hand, ultrasound and radiology societies specify the use of contrast-enhanced ultrasound for ruling out liver metastases. Studies focusing on the follow-up of cancer patients are lacking. The goal of this multicenter study initiated by the German Ultrasound Society (DEGUM) was to determine the potential benefit of contrast-enhanced ultrasound in the follow-up of patients with colon cancer. MATERIALS AND METHODS: Follow-up patients with colon cancer (UICC > IIa) were investigated. As scheduled according to the German guidelines, unenhanced ultrasound was performed followed by contrast-enhanced ultrasound. All liver lesions were recorded. In case of additional metastases detected on contrast-enhanced ultrasound, contrast-enhanced CT, MRI or biopsy was performed to confirm additional liver metastases. RESULTS: A total of 45 liver metastases were detected in 26/290 patients (= 9 %) using unenhanced ultrasound. A further 28 metastases were detected on contrast-enhanced ultrasound in these 26 patients. In 18 patients showing no liver metastases, 40 additional metastases were detected on unenhanced ultrasound. This means that 44 patients with a total of 113 liver metastases were detected on contrast-enhanced ultrasound (p = 0.0006). CONCLUSION: Contrast-enhanced ultrasound should be recommended in the follow-up of patients with colon cancer in addition to unenhanced ultrasound - the up-to-date standard.

Incidence of bleeding in 8172 percutaneous ultrasound-guided intraabdominal diagnostic and therapeutic interventions - results of the prospective multicenter DEGUM interventional ultrasound study (PIUS study).

PURPOSE: To analyse the incidence of bleeding after percutaneous ultrasound guided diagnostic and therapeutic intraabdominal interventions in a prospective multicentre study (DEGUM percutaneous interventional ultrasound study). MATERIALS AND METHODS: Within a time period of 2 years diagnostic and therapeutic intraabdominal interventions (with the exclusion of ascites paracentesis) performed percutaneously under continuous ultrasound (US) guidance were prospectively assessed using a pseudonymized standardized web site entry form. Number and type of intervention, operator experience, patient characteristics, medication, lab data as well as technical aspects of the procedure and bleeding complications were analysed according to the interventional radiology standards. RESULTS: 8172 US-guided intraabdominal interventions (liver n = 5903; pancreas n = 501, kidney n = 434, lymph node = 272, biliary system n = 153, spleen n = 63, other abdominal organs and extra-organic targets n = 999) were analysed in 30 hospitals. The majority were diagnostic biopsies including 1780 liver parenchyma, 3400 focal liver lesions and 404 pancreatic lesions. 7525 interventions (92.1 %) were performed in hospitalized patients (mean age 62.6 years). Most operators were highly experienced in US-guided interventions (> 500 interventions prior to the study n = 5729; 70.1 %). Sedation was administered in 1131 patients (13.8 %). Needle diameter was ≥ 1 mm in 7162 punctures (87.9 %) with main focus on core needle biopsies (18 G, n = 4185). Clinically relevant bleeding complications with need of transfusion (0.4 %), surgical bleeding control (0.1 %) and radiological coiling (0.05 %) were very rare. Bleeding complications with fatal outcome occurred in four patients (0.05 %). The frequency of major bleeding complications was significantly higher in patients with an INR > 1.5 (p < 0.001) and patients taking a medication potentially interfering with platelet function or plasmatic coagulation (p < 0.0333). CONCLUSION: This prospective multicentre study confirms the broad spectrum of percutaneous US-guided intraabdominal interventions. However diagnostic liver biopsies dominate with the use of core needle biopsies (18 G). Percutaneous US-guided interventions performed by experienced sonographers are associated with a low bleeding risk. Major bleeding complications are very rare. A pre-interventional INR < 1.5 and individual medication risk assessment are recommended.

Microcirculation of subepithelial gastric tumors using contrast-enhanced ultrasound.

OBJECTIVES: The evaluation of subepithelial tumors of the stomach is normally the domain of gastroscopy and endoscopic ultrasound. We investigated these rare tumors using transabdominal B-mode ultrasound and performed perfusion analysis of these tumors with contrast enhanced ultrasound. METHODS: Patients with gastrointestinal stromal tumors (GIST, n = 3), leiomyoma (n = 1) and schwannoma (n = 1) were routinely examined using conventional B-mode-ultrasound, colour Doppler ultrasound and contrast-enhanced ultrasound (contrast media: Sonovue; ultrasound device: Siemens Acuson Sequoia 512). Gastroscopy, endosonography with puncture of the subepithelial tumor and computed tomography were also performed in all patients. After surgery, the resected stomach tumors were correlated with the preoperative imaging findings. RESULTS: All calculated tumor sizes using any imaging modalities showed a good correlation with the macroscopic tumor sizes ex-vivo. Histologically increased tumor size of the GISTs was correlated with large, central avascular areas. The GISTs and the leiomyoma presented with mixed echogenicity in B-mode-ultrasound. Colour Doppler ultrasound was able to detect some vessels in the periphery of the tumor only. Using contrast-enhanced ultrasound the GISTs and the leiomyoma presented hypervascular. The contrast pattern of these lesions was from the periphery to the centre or diffuse or a progressive centrifugal fill in during the arterial phase. We also registered slowly progressive washout starting at the end of the arterial phase and increasing into the late phase. The contrast media behaviour in the schwannoma was different from that describt above within the GISTs: it was noted to have a diffuse intralesional pattern at the start of the arterial phase followed by an early, rapidly progressing washout-phenomenon. CONCLUSION: In our pilot study B-mode transabdominal ultrasound was able to visualise gastric subepithelial tumors larger than three centimetre. Contrast-enhanced ultrasound is a proven method in clinical practice for the perfusion analysis of gastric subepithelial tumors. It can also be used for the planning of ultrasound-guided biopsies to avoid punctures of necrotic tumor parts.

Contrast-enhanced ultrasound for the characterization of focal liver lesions--diagnostic accuracy in clinical practice (DEGUM multicenter trial).

PURPOSE: To evaluate the diagnostic benefit of contrast-enhanced ultrasound for the differential diagnosis of liver tumors in clinical practice. MATERIALS AND METHODS: From May 2004 to December 2006 1349 patients (male 677, female 672) with a hepatic tumor lacking a definite diagnosis based on B-mode ultrasound and power Doppler ultrasound were examined at 14 hospitals by contrast-enhanced ultrasound using a standardized protocol (pulse/phase inversion imaging, mechanical index < 0.4). The Tumor status was assessed based on the vascularity pattern and contrast enhancement seen in focal lesions during the arterial, portal, and late phase. The diagnosis established after contrast-enhanced ultrasound was compared to histology (> 75% cases) or in some cases to CT or MRI. RESULTS: The final diagnosis of hepatic tumors included 573 benign hepatic tumors (hemangiomas n = 242, focal nodular hyperplasia n = 170, hepatocellular adenoma n = 19, other benign lesions n = 142) and 755 malignant hepatic tumors (metastases n = 383, hepatocellular carcinoma n = 279, other malignant lesions n= 93). The overall diagnostic accuracy of contrast-enhanced ultrasound in comparison to the correct final diagnosis based on the combined gold standard was 90.3%. Contrast-enhanced ultrasound was able to correctly assess 723/755 malignant lesions (sensitivity 95.8%) and 476/573 benign lesions (specificity 83.1%). The positive predictive value of contrast-enhanced ultrasound for the diagnosis of a malignant tumor was 95.4% and the negative predictive value of contrast-enhanced ultrasound was 95.7%. CONCLUSION: Contrast-enhanced ultrasound clearly improves the differential diagnosis of hepatic tumors and is very helpful in clinical practice when B-scan or power Doppler morphological criteria are missing.