Radiation protection in CT-guided interventions: does real-time dose visualisation lead to a reduction in radiation dose to participating radiologists? A single-centre evaluation.

AIM: To evaluate if real-time dose visualisation during computed tomography (CT)-guided interventions leads to a reduction in radiation dose to participating radiologists. MATERIALS AND METHODS: The individual radiation dose radiologists are exposed to during CT interventions was measured using dedicated dosimeters (RaySafe i2-system, Unfors RaySafe GmbH, Billdal, Sweden) worn over the usual radiation protective apron. Initially, only the total radiation dose was measured, without visualisation (control group). In the following study period, the radiation dose was shown to participants on a live screen in real-time (experimental group). In both groups, the dose was recorded in 1-second intervals. The results collected were evaluated by comparison using descriptive statistics and mixed-effect models. In particular, the variables experience, gender, role, and position during the intervention were analysed. RESULTS: In total, 517 measurements of 304 interventions (n=249 with and n=268 without live screen) performed by 29 radiologists acting as interventionalists or assistants were analysed. All CT-guided interventions were performed percutaneously, the majority of which (n=280) were microwave ablations (MWA). Radiation doses in the group without visualisation were comparable with usual dose rates for the corresponding intervention type. The mean total radiation dose was reduced by 58.1% (11.6 versus 4.86 µSv) in the experimental group (p=0.034). The highest reduction of 78.5% (15.55 versus 3.35 µSv) was observed in radiologists with the role of assistant (p=0.002). Sub-analysis showed significant dose reduction (p<0.0001) for the use of live screen in general; considering all variables, the role "assistant" alone had a statistically significant influence (p=0.002). CONCLUSION: The real-time visualisation of active radiation dose during CT interventions leads to a relevant reduction in radiation dose to participating radiologists.

Continuous-flow DNP polarizer for MRI applications at 1.5 T.

Here we describe a new hyperpolarization approach for magnetic resonance imaging applications at 1.5 T. Proton signal enhancements of more than 20 were achieved with a newly designed multimode microwave resonator situated inside the bore of the imager and used for Overhauser dynamic nuclear polarization of the water proton signal. Different from other approaches in our setup the hyperpolarization is achieved continuously by liquid water flowing through the polarizer under continuous microwave excitation. With an available flow rate of up to 1.5 ml/min, which should be high enough for DNP MR angiography applications in small animals like mice and rats. The hyperpolarized liquid cooled to physiological temperature can be routed by a mechanical switch to a quartz capillary for injection into the blood vessels of the target object. This new approach allows hyperpolarization of protons without the need of an additional magnet and avoids the losses arising from the transfer of the hyperpolarized solution between magnets. The signal-to-noise improvement of this method is demonstrated on two- and three-dimensional phantoms of blood vessels.

Intra-individual comparison of CAIPIRINHA VIBE technique with conventional VIBE sequences in contrast-enhanced MRI of focal liver lesions.

PURPOSE: To evaluate the impact of controlled aliasing in parallel imaging results in higher acceleration (CAIPIRINHA) volume interpolated breath-hold examination (VIBE) magnetic resonance imaging (MRI) technique on image quality, reader confidence, and inter-observer agreement for the assessment of focal liver lesions in comparison with the standard VIBE approach. MATERIAL AND METHODS: In this IRB-approved intra-individual comparison study, abdominal arterial and portal-venous contrast-enhanced MRI studies were retrospectively analyzed in 38 patients with malignant liver lesions. Each patient underwent both CAIPIRINHA and conventional VIBE 3T MRI within 3 months, showing stable disease. Images were evaluated using 5-point rating scales by two blinded radiologists with more than 20 and 5 years of experience in MRI, respectively. Readers scored dignity of liver lesions and assessed which liver segments were affected by malignancy (ranging from 1=definitely benign/not affected to 5=definitely malignant/affected by malignancy). Readers also rated overall image quality, sharpness of intrahepatic veins, and diagnostic confidence (ranging from 1=poor to 5=excellent). RESULTS: Reviewers achieved a higher inter-observer reliability using CAIPIRINHA when they reported which liver segments were affected by malignancy compared to traditional VIBE series (κ=0.62 and 0.54, respectively, p<0.05). Similarly, CAIPIRINHA showed a slightly higher inter-rater agreement for the dignity of focal liver lesions versus the standard VIBE images (κ=0.50 and 0.49, respectively, p<0.05). CAIPIRINHA series also scored higher in comparison to standard VIBE sequences (mean scores: image quality, 4.2 and 3.5; sharpness of intrahepatic vessels, 3.8 and 3.2, respectively, p<0.05) for both reviewers and allowed for higher subjective diagnostic confidence (ratings, 3.8 and 3.2, respectively, p<0.05). CONCLUSION: Compared to the standard VIBE approach, CAIPIRINHA VIBE technique provides improved image quality and sharpness of intrahepatic veins, as well as higher diagnostic confidence. Additionally, this technique allows for higher inter-observer agreement when reporting focal liver lesions for both dignity and allocation.

Minimally invasive screw fixation of fractures in the thoracic spine: CT-controlled pre-surgical guidewire implantation in routine clinical practice.

AIM: To evaluate the feasibility and accuracy of minimally invasive, transpedicular screw placement in cervicothoracic fractures with the help of computed tomography (CT)-controlled guidewires. MATERIALS AND METHODS: Two hundred and ninety-three guidewires were inserted in 35 patients (42.9±21.2 years) under CT fluoroscopy (286 thoracic, seven cervical). There were 28 traumatic cases, three pathological fractures, three fractures due to infectious infiltrations, and one osteoporotic fracture. In 151 pedicles, screw placement was performed in the CT room. CT images were reviewed regarding accuracy and cortical violations using the popular 2 mm increment deviation classification of Gertzbein and Robbins. RESULTS: Guidewire implantation resulted in only 28 cortical contacts. Minor encroachments of the pedicle wall by inserted screws occurred in 39.1% (59 of 151) and in 23.8% if taking unavoidable encroachments into account (30 of 59). Pedicular isthmus width correlated to cortical guidewire contacts (r=-0.449; p=0.077) and pedicle violations (all graded "A") by the inserted screws (r=-0.581; p=0.049). Total procedural duration was 138.6±44.2 minutes, representing 14.5±11.6 minutes for each pedicle, while showing a significant correlation against higher vertebral levels (r=-0.849; p=0.0002) and the occurrence of pedicle violations (r=-0.641; p=0.027). CONCLUSIONS: The treatment of vertebral fractures with a guidewire-based pedicle screw insertion technique under CT imaging results in very high accuracy and a low complication rate.

Radiation dose and quickness of needle CT-interventions using a laser navigation system (LNS) compared with conventional method.

PURPOSE: The aim of this study was to analyse the radiation dose and quickness of needle interventions using a Laser Navigation System (LNS-group) compared with conventional method (control-group). MATERIALS AND METHODS: In this prospective, randomized, comparative study 58 patients (19 females, 39 males; mean age, 62.9 years) were punctured either with LNS (n=29) or with conventional method with a skin mark of the puncture site (n=29). In the LNS method the puncture site was marked with laser without additional CT. Thoracic and abdominal intervention was performed in 30 and 28 patients, respectively. Radiation dose and time of the procedures were analysed. Statistical significance was calculated according to the Mann-Whitney-U-test. RESULTS: Mean target access path in the patients of the LNS group was 6.0 cm (range, 3.0-10.1cm) and in the control group 6.0 cm (range, 1.0-10.3 cm). Time duration of complete intervention in the LNS group was 20:25 min (range, 07:00-34:00 min) and in the control group 28:00 min (range, 13:00-51:00 min). The dose-length-product (DLP) of intervention scan of the LNS group was 42.3 mGy cm (range, 10-125 mGy cm), and of the control group 59.7 mGy cm (range, 25-176.42 mGy cm). CONCLUSION: Using the LNS for CT-guided interventions results in faster intervention time with a lower dose.

Magnetic resonance imaging evaluation of lipodystrophy in HIV-positive patients receiving highly active antiretroviral therapy.

We evaluated retrospectively an automated method for the separate detection of subcutaneous and visceral fat in the abdominal region by magnetic resonance studies in HIV-positive patients on highly active antiretroviral therapy. The patients were divided into four different groups: lipoatrophy, lipohypertrophy, mixed and the control group. The use of software for the automated detection of abdominal compartment visceral adipose tissue (VAT), total adipose tissue (TAT) and subcutaneous adipose tissue (SAT) was compared to manual evaluation methods (fuzzy C-mean). The results of ROC analysis showed that the parameters, particularly the VAT, are better than the VAT/TAT and at identifying patients with the symptoms of abdominal fat accumulation. A sensitivity of 80.3% and a specificity of 79.5% resulted from a threshold VAT value of >87 cm(2). Moreover, the manual evaluation method was shown to provide greater values for VAT and the VAT/TAT ratio than those given by the automated method. In the present study, a rapid MRI protocol for the detection and assessment of the course of lipodystrophy was presented and tested on a group of patients with signs of HALS, as well as on an antiretroviral naïve control group.

Body packers on your examination table: How helpful are plain x-ray images? A definitive low-dose CT protocol as a diagnosis tool for body packers.

AIM: To analyze the clinical value and radiation dose of plain x-rays and CT in examining patients suspected of ingesting drug-filled packets. MATERIALS AND METHODS: Thirty-eight patients with suspected internal concealment of drug-filled packets who were examined with plain x-rays or CT or both were included in the study. CT studies were performed using low-dose and standard-dose techniques. All radiographic images were analysed by two radiologists regarding identification of the packets and estimating the effective radiation dose from standard- and low-dose CT versus conventional x-ray examinations. Descriptive calculations were made regarding the number and density of packs and radiation dosage. The diagnostic performance of both radiologists with standard- and low-dose CT was calculated by analysing differences in the mean number of packs found. RESULTS: Thirty-one patients were positively identified as body packers with an average of 13 packs (min: n = 1, max: n = 58, total: n = 390); seven patients were not concealing drug packets. X-ray images were taken of 24 patients prior to CT, thus allowing a direct comparison between the two methods. The correct diagnosis was made in 42%, in 33% the radiologists were uncertain, and in 25% of drug packets were either not or wrongly identified. X-ray imaging had a positive predictive value of 20% with a negative predictive value of 81%. A total of 55 CT examinations were performed on all patients with a mean effective dose of 2 mSv (low dose) versus 9.3 mSv (standard dose). The visibility of packets on low-dose CT images compared to high-dose CT was not reduced: the radiologists identified 385 and 381 of the packets, respectively, with no difference regarding the examination technique (p = 0.24 and p = 0.253, respectively). The radiodensity of all drug-filled packets at CT ranged from 26-292 HU (mean 181.2 HU). CONCLUSION: X-ray imaging of supposed body packers leads to a significant risk of diagnostic errors and additional need for CT. Instead, a single abdominal low-dose CT examination will deliver the correct diagnoses in most cases, leading to safe clinical management of the suspects.

[Surgical treatment of scapholunate ligament injuries: clinical and radiological results]. / Operative Therapie bei skapholunären Bandverletzungen: Klinische und radiologische Ergebnisse.

BACKGROUND: The purpose of this work was to retrospectively evaluate clinical and radiological results after surgical treatment for scapholunate ligament ruptures. MATERIALS AND METHODS: Measurements of range of motion, strength, and angles, as well as postoperative score assessments were performed in 32 patients. RESULTS: The average mobility in the operated wrist was 52° for flexion, extension 57°, radial 24°, ulnar deviation 31° and forearm rotation outward 88° and inward 89°. The recovery of force was 89% compared with the healthy hand. It showed an average skapholunar angle of 63°, a radioulnar angle of 22° and an average carpal height according to Nattrass of 1.49. Our patients rated the operation result with a median DASH score of 11 points (range 0-70.8 points). The median objective Mayo Wrist Score was 80 points (range 45-100 points). CONCLUSION: Surgical treatment of scapholunate ligament rupture, especially against the background of carpal collapse, is a very satisfactory method with very good results in the objective function and strength, and a high level of patient satisfaction.

Chemosaturation with percutaneous hepatic perfusions of melphalan for hepatic metastases: experience from two European centers.

PURPOSE: Chemosaturation with percutaneous hepatic perfusion (PHP; Hepatic CHEMOSAT(®) Delivery System; Delcath Systems Inc, USA) is a minimally invasive, repeatable regional therapy for unresectable hepatic metastases. It uses a system of catheters and filters to isolate hepatic venous blood from the systemic circulation, allowing delivery of high-dose chemotherapy to the hepatic artery. Effluent hepatic venous blood is filtered before being returned to the systemic circulation, thereby reducing exposure to chemotherapy. We describe our experiences with chemosaturation-PHP at 2 European centers. MATERIALS AND METHODS: 14 patients presented unresectable hepatic metastases from solid tumors; 13 received 1 - 3 sessions of chemosaturation-PHP. Melphalan 2.0 (n = 1) or 3.0 (n = 12) mg/kg was given as a 30-minute infusion into the hepatic artery. 12 patients were evaluable for tumor response. RESULTS: One complete (cholangiocarcinoma, n = 1) and 6 partial responses (ocular, n = 3 or cutaneous melanoma, n = 3) were observed, 5 patients had stable disease (ocular melanoma, n = 3; breast cancer, n = 1; gastric cancer, n = 1). Mild to moderate filter-related toxicity (i. e. thrombocytopenia, anemia) was observed immediately post-procedure. Grade 3/4 melphalan-related pancytopenia developed after 1 - 2 weeks. All hematological events were managed effectively with transfusions and/or other supportive measures. The new high-efficiency filter showed milder toxicity and faster recovery. In one case, chemosaturation-PHP was abandoned prematurely due to heparin-induced vaginal bleeding, and one patient died due to retroperitoneal hemorrhage from heparin anti-coagulation. CONCLUSION: Chemosaturation-PHP for non-resectable liver metastases is a feasible treatment option when performed by an experienced multi-disciplinary team. It may be a promising regional therapy for patients with no effective treatment options.

MR-guided laser-induced thermotherapy (LITT) in patients with liver metastases of uveal melanoma.

PURPOSE: Evaluation of the local tumour control rate and survival data for magnetic resonance (MR) imaging-guided laser ablation of uveal malignant melanoma liver metastases by using laser-induced interstitial thermotherapy (LITT). MATERIALS AND METHODS: The LITT was performed in 18 patients with liver metastases (n = 44) from uveal malignant melanoma. All patients tolerated this intervention well. With the Kaplan-Meier method, the survival rates were calculated. Indications for the procedure were defined for patients with no more than five metastases, none of which were larger than 5 cm in diameter: The Indication for LITT treatment were recurrent liver metastases after partial liver resection (22%), locally non-resectable tumours (17%) or metastases in both liver lobes (61%). RESULTS: The mean survival rate for all treated patients was 3.6 years (95% CI: 2.19, 5.06). We started the calculation on the date of diagnosis of the metastases treated with LITT. The median survival was 1.83 years; 1-year survival, 88%; 3-year survival 47%, 5-year survival 17%. Calculated after the first LITT treatment the median survival was 2.8 years (95% CI: 1.0, 5.0). 10 patients were treated by transarterial chemoembolization before LITT. CONCLUSION: MR-guided LITT treatment shows a high local tumour control and survival rates in patients with liver metastases of uveal malignant melanoma.

Hepatic arterial infusion with irinotecan in patients with liver metastases of colorectal cancer: results of an extended phase I study.

BACKGROUND: To define the maximum tolerated dose (MTD) tolerability and efficacy of intra-arterial chemotherapy with irinotecan in patients with liver metastases of colorectal carcinoma (CRC). METHODS: Superselective intra-arterial irinotecan was applied on days 1, 14, 28 and 42. The initial dose was 140 mg/m² with escalation in the subsequent patient group to 160 mg/m². The final protocol toxicity evaluation was 260 mg/m². Patients required histologically proven disease and adequate bone marrow, liver and renal function, no extrahepatic metastasis and a life expectancy >12 weeks. results: Thirty-three patients were enrolled (median age 65, range 49-78 years). On dose level VI (240 mg/m²), 1 case of dose-limiting toxicity (DLT) (granulocytopenia) was observed, leading to an enlarged cohort of 6 patients. As no additional DLT was detected on this level, an escalation to level VII was performed. On the dose level of 260 mg/m², irinotecan DLTs were observed, resulting in the termination of escalation and the declaration of dose level VI as MTD. Imaging follow-up with Response Evaluation Criteria in Solid Tumors (RECIST) criteria revealed a complete response in 1 patient, stable disease in 31 patients, and progressed disease in 1 patient. The median time to progression was 4.7 months, the median overall survival 15.6 months. CONCLUSION: The method of intra-arterial chemotherapy with irinotecan is well tolerated and shows promising local response rates in liver metastases of CRC.

[Treatment of liver metastases of colorectal carcinoma: overview of hyperthermal ablation methods]. / Therapie von Lebermetastasen des kolorektalen Karzinoms: Übersicht der hyperthermen Ablationsverfahren.

AIM AND METHOD: This paper presents the basic techniques and clinical results of the most common hyperthermal ablation methods for patients with malignant liver metastases of colorectal carcinoma. An overview of recently published data is provided using selected articles from the literature and our own clinical experience in an interdisciplinary liver centre. RESULTS: Radiofrequency ablation (RFA), microwave ablation (MWA) and laser ablation (LITT) show comparable results concerning survival data. Local recurrence is less frequent after LITT (7,1-10%) than after RFA (32-44%) and MWA (7-15%). Survival depends on many factors. The 3-year survival rate for RFA ranges from 20,2-71,3%, for MWA it is 51,1% and for LITT from 56-77%. Mean complication rates range from 1,8-10%. Recent studies showed promising results after combined therapy of regional chemotherapy or regional radiotherapy with thermal ablation. CONCLUSION: Ablation methods such as RFA, MWA and LITT show good local tumor control with low complication rates and are usually performed on an outpatient basis. Indications are <5 metastases limited to the liver with a maximum diameter of ≤4 cm when surgical resection is contraindicated or has been previously performed. The decision should be made by an interdisciplinary tumor board.

Endovascular embolisation therapy in men with erectile impotence due to veno-occlusive dysfunction.

OBJECTIVES: To evaluate the impact of endovascular embolisation therapy in men with erectile impotence due to veno-occlusive dysfunction. METHODS: We retrospectively evaluated 29 patients with a history of erectile impotence due to veno-oclusive dysfunction confirmed by pharmacocavernosometry and cavernosography. All underwent endovascular embolisation therapy over transfemoral approach. After positioning the catheter system at the target level heights, embolisation with N-butyl-2-cyanoacrylate (Histoacryl(®)) was performed. Technical and clinical success as well as major and minor complications were evaluated. RESULTS: All procedures were performed without any major or minor events. Complication rate was 0%. Technical success was achieved in 27/29 (93.1%). Two patients failed for anatomical reasons. Overall clinical success was achieved in 24/27 (88.8%) patients with recovering from E1 (poor tumescense/no rigidity) to E4 (good tumescence/intermediate rigidity) in 11/27 (40.7%), E1 to E5 in 8/27 (tumescence/normal rigidity) (29.6%) and E1 to E3 (good tumescence/poor rigidity) in 5/27 (18.5%) respectively. 3/27 (11.1%) received no change in ED severity score. CONCLUSION: Endovascular embolisation therapy for veno-occlusive dysfunction in erectile impotence is a safe and effective therapeutic option with low complication rate and highly technical and clinical success rates.

Stenting of stenotic mesenteric arteries for symptomatic chronic mesenteric ischemia.

BACKGROUND: We report the results of our single center series of patients with chronic mesenteric ischemia (CMI) to determine the role of stenting in the management of patients. PATIENTS AND METHODS: We retrospectively reviewed all patients with CMI treated endovascularly with stent revascularisation from January 2008 to January 2011.CMI diagnosis was made according to clinical symptoms, including postprandial abdominal pain, food fear, and weight loss. Additionally, the diagnosis was confirmed by duplex ultrasonography and/or computed tomography angiography and/or contrast-enhanced magnetic resonance angiography. RESULTS: All 45 patients presented with typical CMI symptoms: 45/45 (100 %) had postprandial pain, 31/45 (68.8 %) had a weight loss of more than 10 kilograms, and 11/45 (24.4 %) suffered from ischemic colitis combined with lower gastrointestinal bleeding. In three patients occlusion could not be crossed, therefore considered as technical failure. A total of 55 arteries were stented in the remaining 42 patients. Nineteen patients underwent SMA stenting alone, eight underwent celiac stenting, alone and three patients underwent stenting of inferior mesenteric artery (IMA) alone. We performed combined stenting of the celiac artery and superior mesenteric artery in ten patients, and one patient underwent a combined stenting of the celiac artery and the IMA. All three mesenteric arteries were stented in only one patient. Primary technical success was achieved in 42/45 (94.8 %) patients. Clinical symptom relief was achieved in 39/45 (86.6 %) patients with abdominal pain. Increased body weight was observed in 28/31 (90.3 %) patients with an average weight gain of 8.8 kilograms (5 - 12 kilograms), and 10/11 (90.9 %) patients recovered from ischaemic colitis/lower gastrointestinal bleeding. CONCLUSIONS: Stent revascularisation can be considered as the first-line therapy for patients with chronic mesenteric ischemia.

First human study in treatment of unresectable liver metastases from colorectal cancer with irinotecan-loaded beads (DEBIRI).

The objective of this pilot clinical study was to assess the safety, technical feasibility, pharmacokinetic (PK) profile and tumour response of DC Bead™ with irinotecan (DEBIRI™) delivered by intra-arterial embolisation for the treatment of metastatic colorectal cancer. Eleven patients with unresectable liver metastases from CRC, tumour burden <30% of liver volume, adequate haematological, liver and renal function, performance status of <2 were included in this study. Patients received up to 4 sessions of TACE with DEBIRI at 3-week intervals. Feasibility of the procedure, safety and tumour response were assessed after each cycle. PK was measured after the first cycle. Patients were followed up to 24 weeks. Only mild to moderate adverse events were observed. DEBIRI is a technically feasibile procedure; no technical complications were observed. Average Cmax for irinotecan and SN-38 was 194 ng/ml and 16.7 ng/ml, respectively, with average t½ of 4.6 h and 12.4 h following administration of DEBIRI. Best overall response during the study showed disease control in 9 patients (2 patients with partial response and 7 with stable disease, overall response rate of 18%). Our study shows that transarterial chemoembolisation with irinotecan-loaded DC beads (DEBIRI) is safe, technically feasible and effective with a good PK profile.

[Radiological diagnosis and intervention of cholangiocarcinomas (CC)]. / Radiologische Diagnostik und Intervention von Cholangiokarzinomen (CC).

To present current data on diagnosis, indication and different therapy options in patients with cholangiocarcinoma (CC) based on an analysis of the current literature and clinical experience. The diagnostic routine includes laboratory investigations with parameters of cholestasis and also serum tumor markers CA19 - 9 and CEA. After ultrasound for clarifying a tumor and/or dilated bile ducts, contrast-enhanced magnetic resonance imaging (MRI) should be performed with magnetic resonance cholangiography (MRCP). The accuracy (positive predictive value) for diagnosing a CC is 37-84% (depending on the location) for ultrasound, 79-94% for computed tomography (CT), and 95% for MRI and MRCP. An endoscopic retrograde cholangiography (ERCP) can then be planned, especially if biliary drainage or cytological or histological specimen sampling is intended. A curative approach can be achieved by surgical resection, rarely by liver transplantation. However, many patients are not eligible for surgery. In addition to systemic chemotherapy, locoregional therapies such as transarterial chemoembolization (TACE), hepatic arterial infusion (HAI)--also known as chemoperfusion--, drug eluting beads-therapy (DEB) as well as thermoablative procedures, such as laser-induced thermotherapy (LITT), microwave ablation (MWA) and radiofrequency ablation (RFA) can be provided with a palliative intention.

Repeated transarterial chemoembolisation using different chemotherapeutic drug combinations followed by MR-guided laser-induced thermotherapy in patients with liver metastases of colorectal carcinoma.

BACKGROUND: To evaluate a treatment protocol with repeated transarterial-chemoembolisation (TACE) downsizing before MR-guided laser-induced interstitial thermotherapy (LITT) using different chemotherapeutic combinations in patients with unresectable colorectal cancer (CRC) liver metastases. METHODS: Two hundred and twenty-four patients were included in the current study. Transarterial-chemoembolisation (mean 3.4 sessions per patient) was performed as a downsizing treatment to meet the LITT requirements (number5, diameter <5 cm). The intra-arterial protocol consisted of either Irinotecan and Mitomycin (n=77), Gemcitabine and Mitomycin (n=49) or Mitomycin alone (n=98) in addition to Lipiodol and Embocept in all patients. Post TACE, all patients underwent LITT (mean 2.2 sessions per patient). RESULTS: Overall, TACE resulted in a mean reduction in diameter of the target lesions of 21.4%. The median time to progression was 8 months, calculated from the start of therapy and the median local tumour control rate was 7.5 months, calculated as of therapy completion. Median survival of patients calculated from the beginning of TACE was 23 months (range 4-110 months), in patients treated with Irinotecan and Mitomycin the median was 22.5 months, Gemcitabine and Mitomycin 23 months and Mitomycin only 24 months with a statistically significant difference between the groups (P<0.01). CONCLUSION: Repeated TACE offers adequate downsizing of CRC liver metastases to allow further treatment with LITT. The combined treatment illustrates substantial survival rates and high local tumour control with statistically significant differences between the three protocols used. Further randomised trials addressing the current study results are required.

Role of uterine artery Doppler in the management of uterine leiomyoma by arterial embolization.

OBJECTIVES: To study Doppler changes in the uterine artery immediately following and 3 months after uterine artery embolization (UAE) and to test the feasibility of using uterine artery Doppler as a predictor of the predominant side of arterial supply to leiomyomas, amount of embolizing material needed and leiomyoma tumor volume at follow-up. METHODS: The study included 38 patients undergoing UAE for leiomyomas. Uterine artery Doppler was performed transabdominally before, within 6 hours after and 3 months after UAE to determine the peak systolic (PSV) and end-diastolic (EDV) velocities and resistance index (RI). Leiomyoma volume was measured using contrast-enhanced magnetic resonance imaging (MRI) before and 3 months after UAE. The predominant side of arterial supply to the leiomyoma was determined on digital subtraction angiography using the uterine artery diameter and tumor blush after contrast injection. For correlations with leiomyoma volume, the average PSV, EDV and RI of both sides was used, while for prediction of the predominant side of supply and for correlation with the amount of embolizing material needed, separate measurements from each side were used. RESULTS: Relative to the pre-embolization value, the uterine artery PSV and EDV were significantly reduced (P < 0.05) immediately following UAE, while the RI was significantly elevated (P < 0.05). For prediction of the predominant side of supply, the lowest RI showed the highest accuracy (81.6%). There was no significant correlation between the pre-embolization PSV, EDV or RI and the amount of embolizing material utilized. Immediately post-embolization EDV and RI values were statistically significantly correlated with the 3-month follow-up leiomyoma volume, with RI showing the strongest correlation (P = 0.0400 and 0.0002, rho = 0.34 and - 0.58, respectively). The leiomyoma volume was predicted to have reduced by 38-61% after 3 months if the immediate post-embolization average RI value was between 0.82 and 0.88. CONCLUSION: Pre-interventional Doppler assessment can be used to predict the predominant side of supply to leiomyomas but not the amount of embolizing material needed. Immediate post-interventional Doppler assessment can predict the leiomyoma volume after UAE.

[Robot-assisted biopsies in a high-field MRI system - first clinical results]. / Roboterunterstützte Punktion in einem Hochfeld-Kernspintomografen - erste klinische Ergebnisse.

PURPOSE: The purpose of this study was to examine the clinical use of MR-guided biopsies in patients with suspicious lesions using a new MR-compatible assistance system in a high-field MR system. MATERIALS AND METHODS: Six patients with suspicious focal lesions in various anatomic regions underwent percutanous biopsy in a high-field MR system (1.5 T, Magnetom Espree, Siemens) using a new MR-compatible assistance system (Innomotion). The procedures were planned and guided using T 1-weighted FLASH and TrueFISP sequences. A servopneumatic drive then moved the guiding arm automatically to the insertion point. An MRI compatible 15G biopsy system (Somatex) was introduced by a physician guided by the needle holder and multiple biopsies were performed using the coaxial technique. The feasibility, duration of the intervention and biopsy findings were analyzed. RESULTS: The proposed new system allows accurate punctures in a high-field MR system. The assistance device did not interfere with the image quality, and guided the needle virtually exactly as planned. Histological examination could be conducted on every patient. The lesion was malignant in four cases, and an infectious etiology was diagnosed for the two remaining lesions. Regarding the differentiation of anatomical and pathological structures and position monitoring of the insertion needle, TrueFISP images are to be given preference. The average intervention time was 41 minutes. Lesions up to 15.4 cm beneath the skin surface were punctured. CONCLUSION: The proposed MR-guided assistance system can be successfully utilized in a high-field MR system for accurate punctures of even deep lesions in various anatomic regions.

Radiofrequency ablation in experimental bone metastases using a controlled and navigated ablation device.

BACKGROUND: Radiofrequency ablation is a minimal invasive therapy in the treatment of bone metastases. In this study we present a new ablation system enabling an ablation in multiple directions and with an adaptable size and shape. MATERIAL AND METHODS: VX-2 tumor was used for the induction of experimental bone metastases in the femur of six New Zealand white rabbits. X-ray imaging as well as CT and MRI scans before and after treatment was carried out. After detecting bone tumor, radiofrequency ablation was performed. The ablation instrument contained a 10 g bipolar, articulated extendable electrode and a proprietary generator with an impedance controlled algorithm. All bones and the soft tissue were examined histologically. RESULTS: All animals developed local bone tumor. Mean duration until first osteolytic lesions on CT-scans was 48±14 days. The mean lesion area was 26 mm(2). No systemic tumor spread was seen. 6 radiofrequency procedures were carried out with a mean application time of 6 min±2:30 and an average temperature in the region of effect of 55 °C±4. MRI imaging demonstrated an ablation zone of 23±6 mm around the electrode. Histopathology showed an extensive heat necrosis with no remaining tumor cells in the ablation area. CONCLUSION: Radiofrequency ablation is a quickly developing treatment option on the field of minimal invasive bone tumor therapy. The electrode enables an ablation adapted to size and shape of the metastases. Further clinical studies are necessary to test and enhance this radiofrequency system.