What are the potential limitations of drug coated balloons and possible ways to overcome.

In several independent randomized clinical studies, it has been shown that drug-coated balloons (DCBs) cause persistent clinically meaningful and statistically significant inhibition of restenosis in femoropopliteal arteries in comparison to percutaneous transluminal angioplasty with uncoated balloon catheters. The potential benefits of delivering an antiproliferative drug into the vessel wall using a balloon as transporter are manifold: 1) widespread applicability: balloon angioplasty is suitable for use in a wide range of lesions. The use of DCBs is technically less demanding and offers greater flexibility compared with stenting techniques. 2) Maintaining options: minimizing the use of durable implants is providing more options for following and complementary revascularization procedures; 3) proven efficacy: consistent, positive outcomes across studies and key subgroups have been demonstrated from the first preclinical studies to ongoing clinical trials. Beside the enthusiasm carried along with this novel technique and questioning if DCBs will become standard-of-care-therapy for the superficial femoral artery, the potential limitations have to be discussed.

CsI-detector-based dual-exposure dual energy in chest radiography for lung nodule detection: results of an international multicenter trial.

To assess both sensitivity and specificity of digital chest radiography alone and in conjunction with dual-exposure dual-energy chest radiography for the detection and classification of pulmonary nodules. One hundred patients with a total of 149 lung nodules (3-45 mm; median, 11 mm) confirmed by CT were included in this study. Dual-exposure dual-energy chest radiographies of each patient were obtained using a CsI detector system. Experienced board-certified chest radiologists from four different medical centers in Europe reviewed standard chest radiographs alone and in conjunction with dual-energy images blinded and in random order. The reviewers rated the probability of presence, calcification and malignancy of all lung nodules on a five-point rating scale. Lesions detected were identified by applying a specific coordinate system to enable precise verification by the study leader. A receiver-operating characteristic (ROC) analysis was performed. In addition to the 149 true-positive CT proven lesions, 236 false-positive lung nodules were described in digital chest radiographies in conjunction with dual-energy chest radiographies. The cumulative sensitivity of chest radiography in conjunction with dual energy was 43%, specificity was 55%. For digital radiography alone, sensitivity was 35% and specifity was 83%. For the dual energy system, positive predictive value was 58%, and negative predictive value was 66% compared to the digital radiography with a positive predictive value of 59% and a negative predictive value of 65%. Areas under the curve in a ROC analysis resulted in 0.631 (95% confidence interval =0.61 to 0.65) for radiography with dual energy and 0.602 (95% confidence interval =0.58 to 0.63) for digital radiography alone. This difference was not statistically significant. For the detection of lesion calcification or the determination of malignancy, ROC analysis also failed to show significant differences. CsI-based flat-panel dual-exposure dual-energy imaging added to standard chest radiography did not show statistically significant improvement for the detection of pulmonary nodules, nor the identification of calcifications, nor the determination of malignancy.

Planning transarterial radioembolization of colorectal liver metastases with Yttrium 90 microspheres: evaluation of a sequential diagnostic approach using radiologic and nuclear medicine imaging techniques.

The purpose of the study was to establish a diagnostic approach to the preparation of patients with colorectal liver metastases considered for transarterial radioembolization (RE). Twenty-two patients sequentially underwent computed tomography (CT; thorax/abdomen), magnetic resonance imaging (MRI; liver; hepatocyte-specific contrast), positron emission tomography (PET/PET-CT; F18-fluoro-desoxy-glucose), and angiography with perfusion scintigraphy [planar imaging; tomography with integrated CT (SPECT-CT)]. The algorithm was continued when no contraindication or alternative treatment option was found. The impact of each test on the therapy decision and RE management was recorded. Patient evaluation using CT revealed contraindications for RE in 4/22 patients (18%). Of the remaining 18 patients, 2 were excluded and 3 were assigned to locally ablative treatment based on MRI and PET results (28%). The remaining 13 patients entered the planning algorithm: SPECT-CT revealed gastrointestinal tracer accumulations in 4 (31%) patients [SPECT, 2 (15%)], making a modified application necessary. In five patients (38%), planar scintigraphy revealed relevant hepatopulmonary shunting. Therapy was finally administered to all 13 patients without therapy-related pulmonary or gastrointestinal morbidity. Each part of the diagnostic algorithm showed a relevant impact on patient management. The sequential approach appears to be suitable and keeps the number of unnecessary treatments and therapy risks to a minimum.

Sonographically guided venous puncture and fluoroscopically guided placement of tunneled, large-bore central venous catheters for bone marrow transplantation-high success rates and low complication rates.

BACKGROUND AND OBJECTIVE: Traditionally, large lumen, tunneled central venous catheters have been implanted by surgeons. We used a technique of sonographically guided jugular venous puncture and fluoroscopically guided catheter placement to achieve a high rate of technical success and to reduce complication rates. MATERIALS AND METHODS: Between June 2002 and December 2006, 186 Patients have been referred to the Radiology Department for 211 implantations of large-lumen, tunneled, central venous catheters. Insertions were performed under maximum sterile barrier in the angio suite using combined sonographic guidance for puncture of the internal jugular vein and fluoroscopy for placement of a triple lumen 12.5 F catheter (Hickman, BARD Murray Hill, NJ, USA). All interventions were performed under local anesthesia without need for anesthesiologic surveillance. Peri- and postinterventional complications were recorded using standardized international recommendations. RESULTS: Catheter implantation was technically successful in 207 of 211 cases (98.1%). Technical failure resulted in four patients due to chronic occlusions of the superior vena cava. No major complications were recorded. Four (1.9%) accidental arterial punctures occurred peri-interventionally; 24 (11.4%) early complications (bleeding, dysfunction, catheter rupture, and infection) and ten (4.7%) late complications (infection, dysfunction) were recorded. A clinically suspected catheter infection required catheter removal in 21 (10%) cases; 11 of 13 non-infectious catheter complications (bleeding, dysfunction, rupture) could be treated successfully by interventional-radiological treatment. CONCLUSION: Percutaneous implantation of large-lumen, tunneled, central venous catheters can be achieved with a high technical success rate and a low complication rate under combined sonographic and fluoroscopic guidance. In cases of mechanical complications, catheter rescue by interventional techniques is possible in the vast majority of cases.

Radiofrequency ablation in combination with embolization in metachronous recurrent renal cancer in solitary kidney after contralateral tumor nephrectomy.

PURPOSE: To evaluate the feasibility and safety of minimally invasive, percutaneous techniques in metachronous recurrent renal cell cancers (RCCs) in solitary kidneys. METHODS: In 4 patients, recurrent RCC was treated by radiofrequency ablation (RFA) (RITA, StarBurst) alone, and in 2 patients by RFA in combination with superselective transarterial particle-lipiodol embolization using 3 Fr microcatheters. RFA was guided by computed tomography in 5 patients, and by magnetic resonance imaging in 1 patient. Mean tumor diameter was 26.7 mm (range 10-45 mm). All interventions were technically successful; during follow-up 1 patient developed recurrent RCC, which was retreated by RFA after embolization. RESULTS: No major peri- or postprocedural complications occurred. Changes in creatinine (pre- vs. post-intervention, 122 vs. 127 micromol/l) and calculated creatinine clearance (pre- vs. post-intervention, 78 vs. 73 ml/min) after ablation were minimal. CONCLUSION: In single kidneys, percutaneous, minimally invasive techniques are safe and feasible. In large tumors, or where there are adjacent critical structures, we prefer a combination of embolization and thermal ablation (RFA).

Liver malignancies: CT-guided interstitial brachytherapy in patients with unfavorable lesions for thermal ablation.

PURPOSE: To evaluate computed tomography (CT)-guided brachytherapy in patients with very large liver malignancies or with liver tumors located adjacent to the liver hilum. MATERIALS AND METHODS: In this prospective nonrandomized phase II trial, we treated 20 patients (19 liver metastases and one cholangiocarcinoma) with CT-guided high-dose-rate (HDR) brachytherapy using a (192) Iridium source. All patients demonstrated no functional liver degradation prior to irradiation. Entry criteria were liver tumors > 5 cm (group A, n = 11, no upper limit) or liver tumors < or = 5 cm adjacent to the liver hilum (group B, n = 9). Dose planning for brachytherapy was performed with three dimensional (3D) CT data acquired after percutaneous applicator positioning. Magnetic resonance (MR) imaging follow-up was performed 6 weeks and every 3 months post intervention. Primary endpoints were complications, local tumor control (absence of tumor growth after treatment followed by shrinkage of the lesion starting at 6 months) and progression-free survival. RESULTS: The mean tumor diameter was 7.7 cm (range, 5.5-10.8 cm) in group A, 3.6 cm (range, 2.2-4.9 cm) in group B. On average, a minimal dose of 17 Gy in the target volume was applied (range, 12-25 Gy). Severe side effects were recorded in two patients (10%). One patient demonstrated an obstructive jaundice caused by tumor edema after irradiation of a metastasis adjacent to the bile duct bifurcation. One patient developed intra-abdominal hemorrhage that was treated by a single blood transfusion and has ceased. We frequently encountered moderate increases of liver enzymes (70% of patients) and bilirubin (50% of patients) without clinical symptoms and thus considered to be insignificant. The median follow-up was 13 months. In group A (tumors > 5 cm), primary local tumor control after 6 and 12 months was 74% and 40%, respectively; in group B, it was 100% and 71%, respectively. All but one local recurrence (in a patient with diffuse tumor progression) were successfully treated during another CT-guided brachytherapy leading to a primary assisted local control of 93% after 12 months. CONCLUSION: CT-guided brachytherapy based on individual dose plans and 3D CT data sets generated encouraging results in large liver malignancies as well as in tumors located adjacent to the liver hilum.

[CT-Guided brachytherapy. A novel percutaneous technique for interstitial ablation of liver metastases]. / CT-gesteuerte Brachytherapie. Eine neue perkutane Technik zur interstitiellen Ablation von Lebermetastasen.

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 (192)Ir 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 > or = 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.

CT-guided interstitial brachytherapy of liver malignancies alone or in combination with thermal ablation: phase I-II results of a novel technique.

PURPOSE: To assess the safety and efficacy of CT-guided brachytherapy alone or in combination with laser-induced thermotherapy (LITT) in patients with liver malignancies. METHODS AND MATERIALS: Thirty-seven patients presented with 36 liver metastases and two primary liver carcinomas. Twenty-one patients were treated with CT-guided high-dose-rate brachytherapy alone using a 192Ir source. Sixteen patients received brachytherapy directly after MRI-guided LITT. The indications for brachytherapy alone were a tumor size >5 cm, adjacent central bile duct or adjacent major vessels causing unfavorable cooling effects for thermal ablation, and technical failures of LITT. The dosimetry for brachytherapy was performed using three-dimensional CT data acquired after percutaneous applicator positioning. On average, a minimal dose of 17 Gy inside the tumor margin was applied (range, 10-20 Gy). RESULTS: The mean tumor size was 4.6 cm (range, 2.5-11 cm). The mean liver volume receiving > or =5 Gy was 16% (range, 2-40%) of the total liver. Severe complications were recorded in 2 patients (5%). One patient developed acute liver failure possibly related to accidental continuation of oral capecitabine treatment. Another patient demonstrated obstructive jaundice owing to tumor edema after irradiation of a metastasis adjacent to the bile duct bifurcation. A commonly encountered moderate increase of liver enzymes was greatest in patients with combined treatment. The local control rate after 6 months was 73% and 87% for combined treatment and brachytherapy alone, respectively. CONCLUSION: CT-guided brachytherapy using three-dimensional CT data for dosimetry is safe and effective alone or in combination with LITT. Brachytherapy as a stand-alone treatment displayed genuine advantages over thermal tumor ablation.

Percutaneous transluminal laser angioplasty versus balloon dilation for treatment of popliteal artery occlusions.

PURPOSE: To compare the immediate results, complication rates, and long-term outcomes of percutaneous transluminal laser angioplasty (PTLA) versus balloon dilation alone in the treatment of popliteal artery occlusions. METHODS: In a prospective nonrandomized study conducted between December 1994 and June 2000, 215 symptomatic patients with unilateral popliteal occlusions were treated with either dilation alone (88 patients: 52 men; mean age 62 years, range 48-83) or PTLA (127 patients: 70 men; mean age 64 years, range 49-86) using a 308-nm excimer laser followed by dilation. The average occlusion length was 10.4 cm (range 3-14). RESULTS: PTLA was successful in recanalizing 105 (82.7%) arteries, while the recanalization rate for dilation alone was only 70.4% (62/88; p=0.045). After a mean follow-up of 36 months (range 6-52), the primary and secondary patency rates were 21.7% and 50.8%, respectively, in patients with PTLA and 16.3% and 35.2% in the angioplasty group (p=0.762). The complication rates associated with both techniques were similar. CONCLUSIONS: Although initial recanalization may be better with PTLA, it does not appear to add any long-term benefit over balloon dilation alone.