As the efficacy of brachytherapy prostate treatment is becoming realized, new models of 125I seeds are being introduced. In this article we present thermoluminescent dosimetry (TLD) in a solid water phantom for a new design of 125I seed (UroMed/Bebig Symmetra, Model I25.S06). TLD cubes, LiF TLD-100, from Bicron (Solon, OH) with dimension 1 x 1 x 1 mm3 were irradiated at various distances from the seed at angles ranging from 0 degrees to 90 degrees in 10 degrees increments. The TLD detectors were calibrated by irradiation in a 60Co teletherapy beam. Monte Carlo simulation was used to account for TLD energy dependence and the deviation of solid water composition (as determined by chemical analysis of a sample) from liquid water. Dose rates per unit air kerma strength were determined based on calibrations traceable to the 1999 NIST standard (corrected for NIST measurement errors made in 1999) for the Symmetra seed. Dose data is presented in TG-43 format as a function of distance and angle. Values for lambda, F(r, theta), g(r), and the anisotropy constant are obtained for use in radiation treatment planning (RTP) software. The dose rate constant was determined to be 1.033+/-6.4% cGy h(-1) U(-1), which is comparable to model 6702 and higher than model 6711. We find the relative dose distributions of the Symmetra seed are similar to model 6702, and less anisotropic than model 6711. After accounting for deviation of measured solid water composition from the manufacturer's specification, good agreement between TLD results and Monte-Carlo-aided values was found.

Objectives

ObjectivesThe aim of this feasibility study was to prospectively explore in a dog model of chronic ischemic renal disease (CIRD) the hypothesis that real-time contrast-enhanced ultrasonography (CEUS) can quantitatively evaluate the early perfusion changes of renal cortex.Materials and MethodsIn this animal care and use committee-approved study, the model of CIRD was carried out in healthy dogs (10.0∼12.0 kg, n = 5), by placing the Ameroid ring constrictors on the distal portion of right renal artery through operation. CEUS monitoring of right kidney perfusion was performed by intravenous bolus injection of 0.6 ml Sulfur hexafluoride filled microbubbles (SonoVue; Bracco S.P.A., Milan, Italy) every week after operation. The slope rate of ascending curve (A) and descending curve (α), area under curve (AUC), derived peak intensity (DPI), and time to peak (TTP) were measured in renal cortex using commercial quantification software (Q-LAB version 6; Philips Medical Systems, Bothell,WA,USA). The sensitivity of CEUS was compared with blood serum urea nitrogen (BUN) and serum creatinine (SCr) level.ResultsWith the progression of CIRD, dogs showed delayed enhancement and perfusion in renal CEUS curve. Earliest significant changes happened 4 weeks after operation on DPI and TTP which changed from 13.04±2.71 to 15.58±4.75 dB and 9.03±2.01 to 10.62±6.04 sec, respectively (P<.05).ConclusionsCEUS can display the perfusion changes of CIRD in the early period.

Objectives. To investigate the value of contrast-enhanced ultrasound (CEUS) in guidance of percutaneous biopsy in peripheral pulmonary lesions. Methods. This study focused on 53 patients (male: 38, female: 15, and mean age: 55.7 years ± 10.7) with 53 single peripheral pulmonary lesions. Before core needle (16-gauge) percutaneous biopsy, CEUS were performed in all lesions, with injection of 2.4 mL SonoVue (Bracco, Italy). The contrast-enhancement pattern, display rate of internal necrosis (nonenhanced) and active (obviously enhanced) areas, biopsy success rate, and pathological diagnosis rate were recorded. Results. All the peripheral pulmonary lesions were proved pathologically as benign lesions (n = 7), primary malignancies (n = 41), or metastasis (n = 5). Forty (86.9%) malignant lesions and 4 (57.1%) benign lesions showed internal necrosis areas on CEUS. The detection rate and average size of internal necrosis areas had been significantly improved compared to conventional ultrasound (P < 0.05). After CEUS, core needle percutaneous biopsies were performed successfully in the active areas of all lesions. The sampling success rate and pathological diagnosis rate were 100% and 98.1%. Conclusions. CEUS before biopsy provided useful diagnostic information about peripheral pulmonary lesions. By depicting internal necrotic and active areas, it is a promising technique for guaranteeing the accuracy, success, and safety of core needle biopsy.

A nterior mediastinal tumors are common in clinical settings. Common lesions include inflammatory vs. neoplastic lesions, benign vs. malignant lesions, and primary vs. metastatic lesions. Among these, lymphomas are medically treatable, thymomas are surgically treatable, and metastatic carcinomas are nonresectable (1). Primary mediastinal tumors represent only about 3% of the tumors within the chest wall. Metastatic carcinoma and non-Hodgkin's lymphoma are among common anterior mediastinal tumors. The rates of nonsurgical tumors such as lymphoma are higher than the rates of surgical diseases such as thymomas (2). Some anterior mediastinal tumors such as nonseminomatous germ cell tumors, thymic carcinomas, seminomas, lymphomas, and thymomas are quite similar in medical imaging appearance, but are quite different in treatment strategy; early and precise histopathologic diagnosis of anterior mediastinal lesions is essential for correct therapeutic decision, and remains an interesting diagnostic challenge (3).Several biopsy techniques and approaches have been previously described and are available to obtain specimens of anterior mediastinal lesions, including percutaneous image-guided core needle biopsy, parasternal anterior mediastinotomy, endoscopic ultrasonography (US)-guided biopsy, video-assisted thoracoscopic surgery, cervical mediastinoscopy, and open surgical procedures (1). Most of those procedures require intubation and general anesthesia. Open biopsy is associated with morbidity, chance of pleural dissemination, and poor long-term results. For these reasons, surgically strategies are not suitable for anterior mediastinum lesions (4).In general, US-guided percutaneous core needle biopsy is the first diagnostic choice because it is a minimally invasive, safe, and cost-effective procedure. I N T E R V E N T I O N A L R A D I O LO G Y O R I G I N A L A R T I C L E PURPOSEWe aimed to explore the value of contrast-enhanced ultrasonography (CEUS) in guidance of percutaneous biopsy of anterior mediastinal lesions. METHODSNinety patients with solitary anterior mediastinal lesions (55 males, 35 females; mean age, 46±4 years) were included. Patients were randomly divided into CEUS group (n=45) and conventional ultrasonography (US) group (n=45). Real-time US-guided core needle (16 G) percutaneous biopsies were performed in all lesions. The display of internal mammary arteries, internal necrosis, and active areas were recorded and compared. Biopsy success rate and diagnostic accuracy were compared between the two groups. RESULTSDisplay rate of unenhanced internal necrosis was higher in the CEUS group than in the US group (88.9% vs. 46.7%, P = 0.041). With real-time CEUS guidance, internal mammary arteries were effectively displayed and avoided during biopsies in 68.9% of the lesions (31/45). Of the lesions, 88.9% (80/90) were histologically proven, including 13 benign lesions and 67 malignancies. There was a significant difference in the rate of successful puncture attempts between the two groups (P = 0.041). CEUS gro...

Quantitative analysis of CEUS can show quantification of enhancement features of different renal tumor histotypes and may be helpful in their differential diagnosis.

No abstract

BackgroundAntiangiogenesis is a promising therapy for advanced hepatocellular carcinoma (HCC), but the effects are difficult to be evaluated. Pazopanib (GW786034B) is a pan-vascular endothelial growth factor receptor inhibitor, the antitumor effects or antiangiogenic effects haven't been investigated in HCC.MethodsIn vitro direct effects of pazopanib on human HCC cell lines and endothelial cells were evaluated. In vivo antitumor effects were evaluated in three xenograft nude mice models. In the subcutaneous HCCLM3 model, intratumoral blood perfusion was detected by contrast-enhanced ultrasonography (CEUS), and serial quantitative parameters were profiled from the time-intensity curves of ultrasonograms.ResultsIn vitro proliferation of various HCC cell lines were not inhibited by pazopanib. Pazopanib inhibited migration and invasion and induced apoptosis significantly in two HCC cell lines, HCCLM3 and PLC/PRF/5. Proliferation, migration, and tubule formation of human umbilical vein endothelial cells were inhibited by pazopanib in a dose-dependent manner. In vivo tumor growth was significantly inhibited by pazopanib in HCCLM3, HepG2, and PLC/PRF/5 xenograft models. Various intratumoral perfusion parameters changed over time, and the signal intensity was significantly impaired in the treated tumors before the treatment efficacy on tumor size could be observed. Mean transit time of the contrast media in hotspot areas of the tumors was reversely correlated with intratumoral microvessel density.ConclusionsAntitumor effects of pazopanib in HCC xenografts may owe to its antiangiogenic effects, and the in vivo antiangiogenic effects could be evaluated by quantitative CEUS.