Yvonne L. Hoogeveen

The diagnostic accuracy of CT and MRI in the staging of pelvic lymph nodes in patients with prostate cancer: a meta-analysis

AIM To compare the diagnostic accuracy of computed tomography (CT) and magnetic resonance imaging (MRI) in the diagnosis of lymph node metastases in prostate cancer. METHODS After a comprehensive literature search, studies were included that allowed construction of contingency tables for detection of lymph node metastases using CT or MRI. In addition, a summary receiver-operating characteristic (ROC) analysis was performed. RESULTS A total of 24 studies were included. For CT, pooled sensitivity was 0.42 (0.26-0.56 95% CI) and pooled specificity was 0.82 (0.8-0.83 95% CI). For MRI, the pooled sensitivity was 0.39 (0.22-0.56 95% CI) and pooled specificity was 0.82 (0.79-0.83 95% CI). The differences in performance of CT and MRI were not statistically significant. CONCLUSION CT and MRI demonstrate an equally poor performance in the detection of lymph node metastases from prostate cancer. Reliance on either CT or MRI will misrepresent the patients true status regarding nodal metastases, and thus misdirect the therapeutic strategies offered to the patient.

The 6-F nitinol TrapEase inferior vena cava filter: Results of a prospective multicenter trial

PURPOSE The authors report the first results of a new 6-F symmetrically designed permanent nitinol inferior vena cava (IVC) filter, the Cordis TrapEase, evaluated in a multicenter prospective study with 6-months of follow-up. MATERIALS AND METHODS A total of 65 patients (29 men, 36 women) who ranged in age from 37 to 96 years (mean age, 68 years) and who were at high risk of pulmonary embolism (PE) were enrolled in 12 centers in Europe and Canada. The study was approved by the institutional review boards at all centers. Study objectives were to evaluate filter effectiveness, filter stability, and caval occlusion. Indications for filter placement were deep vein thrombosis with recurrent thromboembolism and/or free-floating thrombus with contraindication to anticoagulation in 37 patients, and complications in achieving adequate anticoagulation in 28 patients. Follow-up included clinical examination, plain film, Doppler ultrasound, CT scan, and nuclear medicine. RESULTS The analysis of the data revealed a technical success of 95.4% (three filter-system related implantations not at the intended site, no events of filter tilting) and a clinical success of 100% at 6 months (no cases of symptomatic PE), the study primary endpoint. There were no cases (0%) of filter migration, insertion site thrombosis, filter fracture, or vessel wall perforation. During the study period, there were two cases of filter thrombosis: one case of early symptomatic thrombosis that was successfully treated in the hospital, and one case of nonsymptomatic filter thrombosis detected at 1-month follow-up, with spontaneous recanalization at 3 months. In the latter patient, some residual thrombus was still detected at 6 months. Of the study population of 65 patients, there were 23 deaths. These deaths were not related to the device or the implantation procedure but to the underlying disease process. CONCLUSION This study demonstrates the new nitinol permanent IVC filter to be a safe and an effective device, with a low overall complication rate, for use in patients with thromboembolic disease at high risk of PE.

Hydrodynamic Thrombectomy of Hemodialysis Fistulas: First Clinical Results

PURPOSE A hydrodynamic thrombectomy system was used for the treatment of recent dialysis shunt thrombosis. PATIENTS AND METHODS Sixteen shunt thromboses in 14 patients were included in the study. There were seven polytetrafluoroethylene grafts and nine native arteriovenous fistulas. Occlusion time ranged from 6 to 48 hours, and thrombus length ranged from 4 to 40 cm. RESULTS Thrombectomy was technically successful in 15 of 16 instances. No significant residual thrombus was found in 15 cases. In one case, half of the thrombus remained in the vessel and the procedure failed technically. One embolus to the radial artery occurred after balloon dilation following hydrodynamic thrombectomy and was removed percutaneously. Early rethrombosis within 24 hours occurred in five shunts; four more rethrombosed within 2 weeks to 3 months. Eleven shunts were available for follow-up. Cumulative patency was 41% after 6 months. CONCLUSION Hydrodynamic thrombectomy is a promising concept for declotting of both hemodialysis grafts and native shunts and may offer an alternative to thrombolysis and surgical thrombectomy.

Value of PET/CT and MR lymphography in treatment of prostate cancer patients with lymph node metastases

PURPOSE To determine the clinical value of two novel molecular imaging techniques: (11)C-choline positron emission tomography (PET)/computed tomography (CT) and ferumoxtran-10 enhanced magnetic resonance imaging (magnetic resonance lymphography [MRL]) for lymph node (LN) treatment in prostate cancer (PCa) patients. Therefore, we evaluated the ability of PET/CT and MRL to assess the number, size, and location of LN metastases in patients with primary or recurrent PCa. METHODS AND MATERIALS A total of 29 patients underwent MRL and PET/CT for LN evaluation. The MRL and PET/CT data were analyzed independently. The number, size, and location of the LN metastases were determined. The location was described as within or outside the standard clinical target volume for elective pelvic irradiation as defined by the Radiation Therapy Oncology Group. Subsequently, the results from MRL and PET/CT were compared. RESULTS Of the 738 LNs visible on MRL, 151 were positive in 23 of 29 patients. Of the 132 LNs visible on PET/CT, 34 were positive in 13 of 29 patients. MRL detected significantly more positive LNs (p < 0.001) in more patients than PET/CT (p = 0.002). The mean diameter of the detected suspicious LNs on MRL was significantly smaller than those detected by PET/CT, 4.9 mm and 8.4 mm, respectively (p < 0.0001). In 14 (61%) of 23 patients, suspicious LNs were found outside the clinical target volume with MRL and in 4 (31%) of 13 patients with PET/CT. CONCLUSION In patients with PCa, both molecular imaging techniques, MRL and (11)C-choline PET/CT, can detect LNs suspicious for metastasis, irrespective of the existing size and shape criteria for CT and conventional magnetic resonance imaging. On MRL and PET/CT, 61% and 31% of the suspicious LNs were located outside the conventional clinical target volume. Therefore, these techniques could help to individualize treatment selection and enable image-guided radiotherapy for patients with PCa LN metastases.

Minor and giant omphalocele: long-term outcomes and quality of life

PURPOSE Long-term outcome and quality of life in omphalocele (OC) studies are mainly focused on cosmetic disorders with the abdominal scar and gastrointestinal disorders. The aim of this study was to compare long-term mortality, morbidity, and quality of life between patients with minor and giant OCs. METHODS Records of 89 minor and 22 giant OC children were reviewed. A questionnaire on general health was sent to all patients. A second questionnaire concerning quality of life and functional status; Darthmouth COOP Functional Health Assessment Charts/WONCA (COOP/WONCA) was sent to all patients aged 18 years or older and a peer control group. RESULTS Of the surviving patients (69 minor OC, 20 giant OC), 12 were lost to hospital follow-up. The first questionnaire was returned by 64 (83%) of 77 patients. There were no significant differences in gastrointestinal disorders. Cosmetic problems were experienced significantly more in giant OC. The results of the COOP/WONCA charts indicated a good to very good quality of life in both groups comparable to the control group. CONCLUSIONS Our study indicates that after a high level of medical intervention perinatally, quality of life is good to very good in both groups and comparable to healthy young adults.

Past and current surgical treatment of giant omphalocele: outcome of a questionnaire sent to authors

PURPOSE Operative treatment of giant omphalocele (OC) is still a challenge for pediatric surgeons. We were interested to ascertain whether published operative techniques for giant OC once advocated by their authors were still being used by these authors and whether the techniques had been modified or even abandoned for other techniques. METHODS Relevant studies concerning the treatment of giant OC were identified by an electronic search. Publication date of the articles was from 1967 to 2009. A questionnaire was sent to the first author or coauthor, unless contact details were unavailable. The described surgical techniques were categorized into primary closure, staged closure, and delayed closure. RESULTS Almost half of the authors (42%), independent of the initial technique used (primary, staged, or delayed closure), changed or stopped using their technique after the publication of the article. The change was not to one particular proven better technique. Herniation rate was lower in delayed closure (9% delayed vs 18% staged vs 58% primary). CONCLUSIONS The results of the questionnaire did not show a generally accepted method of treatment after more than 30 years of innovations in managing patients with a giant OC. There are generally 2 main treatment modalities: staged closure and delayed closure. Because of the lack of large patient numbers and late follow-up, long-term results of the published techniques are needed, and randomized multicenter trials based on these outcomes are recommended. Until then, we remain dependent on expert opinions.

Cone beam CT guidance provides superior accuracy for complex needle paths compared with CT guidance.

OBJECTIVE To determine the accuracy of cone beam CT (CBCT) guidance and CT guidance in reaching small targets in relation to needle path complexity in a phantom. METHODS CBCT guidance combines three-dimensional CBCT imaging with fluoroscopy overlay and needle planning software to provide real-time needle guidance. The accuracy of needle positioning, quantified as deviation from a target, was assessed for inplane, angulated and double angulated needle paths. Four interventional radiologists reached four targets along the three paths using CBCT and CT guidance. Accuracies were compared between CBCT and CT for each needle path and between the three approaches within both modalities. The effect of user experience in CBCT guidance was also assessed. RESULTS Accuracies for CBCT were significantly better than CT for the double angulated needle path (2.2 vs 6.7 mm, p<0.001) for all radiologists. CBCT guidance showed no significant differences between the three approaches. For CT, deviations increased with increasing needle path complexity from 3.3 mm for the inplane placements to 4.4 mm (p=0.007) and 6.7 mm (p<0.001) for the angulated and double angulated CT-guided needle placements, respectively. For double angulated needle paths, experienced CBCT users showed consistently higher accuracies than trained users [1.8 mm (range 1.2-2.2) vs 3.3 mm (range 2.1-7.2) deviation from target, respectively; p=0.003]. CONCLUSION In terms of accuracy, CBCT is the preferred modality, irrespective of the level of user experience, for more difficult guidance procedures requiring double angulated needle paths as in oncological interventions. ADVANCES IN KNOWLEDGE Accuracy of CBCT guidance has not been discussed before. CBCT guidance allows accurate needle placement irrespective of needle path complexity. For angulated and double-angulated needle paths, CBCT is more accurate than CT guidance.

Vena Cava Filter Behavior and Endovascular Response: An Experimental In Vivo Study

AbstractPurpose: To evaluate the behavior and endovascular response of a new nitinol permanent vena cava filter, the TrapEase. Methods: Percutaneous implantation of the filter was performed in six goats, with inferior vena cava (IVC) diameter close to that of man. Radiologic data concerning the IVC, filter diameter, patency and stability were collected. At 2, 4, 20 and 26 weeks post-implantation, histopathologic analysis of the IVC wall was performed at the site of filter distension, and distal and proximal to the filter. Results: All filters remained patent. There was no migration and no signs of biological incompatibility. Signs of neointimalization were seen at 2 weeks, with well-developed neointima at 4 weeks. No acute vessel wall perforation was detected by cavography at implantation. During follow-up histologic analysis at 26 weeks, perforation of some of the small fixation barbs was seen, causing minimal damage to the vessel wall and adjacent organ tissue without impairing organ function. These events were well tolerated, probably due to the gradual nature of the penetration of fixation barbs allowing reactive fibrous tissue development. At 26 weeks the parallel filter struts were well covered with neointima and did not perforate the vessel wall. There were no complications associated with the filter implantation. Conclusions: The TrapEase vena cava filter was well tolerated and is suitable for incorporation into the IVC wall of healthy animals without any apparent deleterious reaction due to biological incompatibility.

Assessment of needle guidance devices for their potential to reduce fluoroscopy time and operator hand dose during C-arm cone-beam computed tomography-guided needle interventions.

PURPOSE To assess whether the use of needle guidance devices can reduce fluoroscopy time and operator hand dose during cone-beam computed tomography-guided needle interventions. MATERIALS AND METHODS The freehand technique was compared with techniques employing two distinct needle holders and a ceiling-mounted laser guidance technique. Laser guidance was used either alone or in combination with needle holders. Four interventional radiologists were instructed to reach predetermined targets in an abdominal phantom using these techniques. Each operator used all six techniques three times. Fluoroscopy time, procedure time, operator hand dose, and needle tip deviation were obtained for all simulated needle interventions. All data are presented as median (ranges). RESULTS All procedures were successfully completed within 2-4 minutes, resulting in a deviation from target of 0.8 mm (0-4.7). In freehand procedures, the fluoroscopy time to reach the target was 50 seconds (31-98 s). Laser guidance, used alone or in combination with needle holders, reduced fluoroscopy time to 31 seconds (14-68 s) (P<.02). The operator hand dose in freehand procedures was 275 μSv (20-603 μSv). Laser guidance alone or in combination with needle holders resulted in a reduction of the hand dose to<36 μSv (5-82 μSv) per procedure (P<.001). There were no statistically significant effects on hand dose levels or fluoroscopy time when the needle holders were employed alone. CONCLUSIONS Compared with the freehand technique, all three tested needle guidance devices performed with equivalent efficiency in terms of accuracy and procedure time. Only the addition of laser guidance was found to reduce both fluoroscopy time and operator hand dose.

Detectability of motions in AAA with ECG-gated CTA : A quantitative study

PURPOSE ECG-gated CT enables the visualization of motions caused by the beating of the heart. Although ECG gating is frequently used in cardiac CT imaging, this technique is also very promising for evaluating vessel wall motion of the aortic artery and the motions of (stent grafts inside) abdominal aortic aneurysms (AAA). Late stent graft failure is a serious complication in endovascular repair of aortic aneurysms. Better understanding of the motion characteristics of stent grafts will be beneficial for designing future devices. In addition, these data can be valuable in predicting stent graft failure in patients. To be able to reliably quantify the motion, however, it is of importance to know the performance and limitations of ECG gating, especially when the motions are small, as is the case in AAA. Since the details of the reconstruction algorithms are proprietary information on the CT manufacturers and not in the public domain, empirical experiments are required. The goal of this study is to investigate as to what extent the motions in AAA can be measured using ECG-gated CT. The authors quantitatively investigate four aspects of motion in ECG-gated CT: The detectability of the motion of objects at different amplitudes and different periodic motions, the temporal resolution, and the volume gaps that occur as a function of heart rate. METHODS They designed an experiment on a standard static phantom to empirically determine temporal resolution. To investigate motion amplitude and frequency, as well as patient heart rate, they designed dynamic experiments in which a home-made phantom driven by a motion unit moves in a predetermined pattern. RESULTS The duration of each ECG-gated phase was found to be 185ms, which corresponds to half of the rotation time and is thus in accordance with half scan reconstruction applied by the scanner. By using subpixel localization, motions become detectable from amplitudes of as small as 0.4mm in the x direction and 0.7mm in the z direction. With the rotation time used in this study, motions up to 2.7Hz can be reliably detected. The reconstruction algorithm fills volume gaps with noisy data using interpolation, but objects within these gaps remain hidden. CONCLUSIONS This study gives insight into the possibilities and limitations for measuring small motions using ECG-gated CT. Application of the experimental method is not restricted to the CT scanner of a single manufacturer. From the results, they conclude that ECG-gated CTA is a suitable technique for studying the expected motions of the stent graft and vessel wall in AAA.