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A 79-year-old woman with a newly detected oval circumscribed lump in subcutaneous location on mammography and ultrasound turned out to be a Schwannoma after ultrasound-guided core needle biopsy. A 72-year-old woman with breast cancer in medical history demonstrated a new axillary mass in follow up, initially regarded as a lymph node metastasis. Core needle biopsy did not lead to a sufficient diagnosis. Pathologic examination after intraoperative sampling revealed a Schwannoma. These 2 case reports illustrate the importance of diagnostic imaging and remind to include Schwannomas in the differential diagnosis of breast and axillary masses.

Purpose To determine the magnetic resonance (MR) sequences best suited for the assessment of ablation zones after radiofrequency ablation (RFA). Methods Three percutaneous MR-guided RFA of the liver were performed on three swine. Four pre-contrast and two hepatobiliary post-contrast sequences were obtained after ablation. Tissue samples were extracted and stained for nicotinamide adenine dinucleotide diaphorase hydride (NADH) and with hematoxylin and eosin. Post-ablation MR images and NADH slides were segmented to determine the total ablation zone, their Dice similarity coefficient (DSC), and the contrast-to-noise ratio (CNR) of the visible ablation boundary to normal liver tissue. Results Two distinct layers were combined to determine the ablation zone: an inner layer of coagulation necrosis and an outer layer defined as the peripheral transition zone. Corresponding zones could be found in the MR images as well. Compared to histology, the total area of the MR ablation zone was significantly smaller on the pre-contrast T1 images (p p = 0.025). No significant difference in size of the ablation zone depiction could be found between histology, post-contrast T1 volumetric interpolated breath-hold examination (VIBE), and post-contrast T1 3D Turboflash (TFL) as well as T2 SPACE images. All sequences but the pre-contrast T1 VIBE sequence showed a DSC above 80% and a high CNR. Conclusions Post-contrast T1 3DTFL performs best when assessing ablation zones after RFA. Since the sequence requires a long acquisition time, T1 VIBE post-contrast offers the best compromise between acquisition time and estimation accuracy.

Background It is well known that physical abuse of children all too often escapes detection. Fractures are among the potential consequences of physical abuse but are also com- mon in childhood because of accidents. A question frequently addressed to the Medical Child Protection Hotline (Medizini- sche Kinderschutzhotline) is how fractures due to abuse can be distinguished from accidental fractures. Methods This review is based on pertinent publications retrieved by a search in PubMed and in the Cochrane Data- base, as well as on the authors' experience in a pediatric emergency department with ca. 29 000 consultations per year and in a child protection outpatient clinic with ca. 100 consultations per year. Results Fractures due to abuse are especially common among infants; their incidence is estimated at 56.8/100 000 among infants less than six months old and 39.8/100 000 among infants aged 6 to 11 months. In consideration of the age of the child, the type of fracture, the history, and other factors, a high probability of abuse can be suspected in many cases, so that further measures can be initiated. Conclusion All physicians involved in the care of children (even if only occasionally) should be aware of the major indicators of likely physical abuse and of the available oppor- tunities for counseling and intervention. Failures to diagnose child abuse are associated with high rates of recurrence and mortality.

Purpose: To find out if the hepatic transit time (HTT) shortening, which was already proven in patients with liver metastases by other modalities, can also be detected with MRI. Materials and Methods: The Patient group consisted of 20 subjects with liver metastases from colorectal cancer and the control group of 21 healthy subjects. Baseline and post contrast images were acquired before and after administration of Gd-BOPTA, using a T1-weighted bolus test sequence. Arrival times (AT) of the contrast agent for the aorta, the hepatic artery, the portal vein and one hepatic vein were determined. Based on arrival time measurements HTT were calculated. Results: All analyses showed significantly shorter HTT in patients with metastases compared with healthy volunteers (P < 0.05). There were no false positives using a threshold of 10.4 s for arterial to venous HTT. For aortal to venous and portal to venous HTT a threshold of 12.5 s and 4 s was calculated, respectively. No significant correlation between HTT and involved liver segments, overall volume of metastases or subject age was found. Conclusion: We conclude that HTT measurements using contrast enhanced MRI with Gd-BOPTA can detect hemodynamic changes due to metastatic liver disease from colorectal cancer. J. Magn. Reson. Imaging 2012; 36:1389–1394. © 2012 Wiley Periodicals, Inc.

In situ ablation is increasingly being used for the treatment of liver malignancies. The application of these techniques is limited by the lack of a precise prediction of the destruction volume. This holds especially true in anatomically difficult situations, such as metastases in the vicinity of larger liver vessels. We developed a three-dimensional (3D) planning system for laser-induced thermotherapy (LITT) of liver tumors. The aim of the study was to validate the system for calculation of the destruction volume.LITT (28 W, 20 min) was performed in close contact to major hepatic vessels in six pigs. After explantation of the liver, the coagulation area was documented. The liver and its vascular structures were segmented from a pre-interventional CT scan. Therapy planning was carried out including the cooling effect of adjacent liver vessels. The lesions in vivo and the simulated lesions were compared with a morphometric analysis.The volume of lesions in vivo was 6,568.3 ± 3,245.9 mm(3), which was not different to the simulation result of 6,935.2 ± 2,538.5 mm(3) (P = 0.937). The morphometric analysis showed a sensitivity of the system of 0.896 ± 0.093 (correct prediction of destructed tissue). The specificity was 0.858 ± 0.090 (correct prediction of vital tissue).A 3D computer planning system for the prediction of thermal lesions in LITT was developed. The calculation of the directional cooling effect of intrahepatic vessels is possible for the first time. The morphometric analysis showed a good correlation under clinical conditions. The pre-therapeutic calculation of the ablation zone might be a valuable tool for procedure planning.

Severe courses of Crohn’s disease (CD) during pregnancy are rare. However, if occurring, the risk of miscarriage and low birth weight is increased. At present, only limited data is available on the treatment of CD during pregnancy. In particular, there are no standard guidelines for surgical therapy. Nevertheless, surgery is often unavoidable if complications during the course of the disease arise. This study provides a critical overview of conventional and interventional treatment options for CD complications during pregnancy and analyses the surgical experience gained thus far. For illustrative purposes, clinical cases of three young women with a severe clinical course during pregnancy are presented. After treatment-refractory for conservative and interventional measures, surgery remained as the only treatment option. In all cases, a split stoma was created after resection to avoid anastomotic leaks that would endanger the lives of mother and child. The postoperative course of all three patients was uneventful, and pregnancy remained intact until delivery. No further CD specific medication was required before birth. The management of CD patients during pregnancy requires close interdisciplinary co-operation between gastroenterologists, obstetricians, anaesthetists and visceral surgeons. For the protection of mother and child treatment should thus be delivered in a specialised centre. This article demonstrates the advantages of surgical therapy by focusing on alleviating CD complaints and preventing postoperative complications.

Einleitung: Die onkologische Sicherheit der Radiofrequenzablation (RFA) ist insbesondere durch den Kühleffekt großer Lebergefäße eingeschränkt. Ziel der vorliegenden Studie war es, ein interdisziplinär entwickeltes Planungssystem für die RFA von Lebertumoren in Hinblick[for full text, please go to the a.m. URL], 127. Kongress der Deutschen Gesellschaft für Chirurgie

This study was designed to evaluate whether the computed tomography (CT) reflects the extent of the inflammation in sigmoid diverticulitis (SD) in order to draw conclusions for selecting the appropriate treatment. Two hundred four patients who underwent resection for SD from January 2003 to December 2008 were included. The preoperative CT stage was compared with intraoperative and histological findings. Patients were classified into phlegmonous (Hansen–Stock IIa), abscess-forming (HS IIb), and free perforated (HS IIc) forms of SD. Patients with a recurrent type of diverticulitis were excluded. In the phlegmonous type (HS IIa; n = 75), we found a correlation with the preoperative stage in 52% (intraoperative) and 56% (histological), an understaging in 12% (intraoperative) and 11% (histological), and an overstaging in 36% (intraoperative) and 33% (histological). In the abscess-forming type (HS IIb, Hinchey I/II; n = 87), we found conformity in 92% (intraoperative) and 90% (histological), understaging in 3% (intraoperative) and 0% (histological), and overstaging in 5% (intraoperative) and 10% (histological). In the presence of a free perforation (HS IIc, Hinchey III/IV; n = 42), we saw conformity in 100% (intraoperative and histological). The positive predictive value for correctly diagnosing of phlegmonous type (HS IIa), abscess-forming type (HS IIb), and free perforation (HS IIc) by CT was intraoperatively (histologically) 52% (56), 92% (90), and 100% (100), respectively. The CT is one of the most accurate methods for staging in SD. However, in the phlegmonous type (HS IIa), it leads to an overestimation of the findings in every third patient. It must be clarified whether this pronounced low inflammation should really be regarded as a complicated form of SD. In contrast, the abscess-forming (HS IIb) and free perforated (HS IIc) type of complicated SD is very well reflected by CT.

Bipolar radiofrequency ablation (RFA) can avoid complications such as thermal tissue damage, a possible consequence of monopolar RFA. However, basic studies about the dosage/effect relationship of bipolar systems are missing. This is systematic research on ex vivo beef livers to find which capacity parameters produce high energy in the tissue and achieve large lesion volumes.The active lengths 20, 30 and 40 mm of a bipolar, internally cooled applicator were studied. The tissue was fresh ex vivo beef liver. Five measurements each for each active applicator with a power between 10 and 50 W were conducted.The best power for the 20 mm applicator was 15 W, since the highest achieved volume was 5,599+/-1,760 mm(3) and the highest amount of energy introduced to the tissue was 15+/-3 kJ. The best power for the 30 mm applicator was 20 W (volume 14,538+/-1,220 mm(3), energy 24+/-1 kJ). For the 40 mm applicator, the best power was 20 W, (volume 20,562+/-896 mm(3), energy 24+/-0 kJ).The results of this study help clinicians determine which active length is required for the applicator and which presetting should be selected to achieve a defined coagulation volume size.

OBJECTIVE:: To evaluate the diagnostic efficacy (accuracy, sensitivity, specificity) of 1.0 M gadobutrol versus 0.5 M gadopentetate for the classification of lesions as either benign or malignant in patients with known or suspected liver lesions. METHODS AND MATERIALS:: A multicenter, phase-III, randomized, interindividually controlled comparison study with blinded reader evaluation was performed to investigate the diagnostic efficacy of a bolus injection of 1.0 M gadobutrol compared with 0.5 M gadopentetate at a dose of 0.1 mmol Gd/kg BW.The imaging protocol included a dynamic 3D-evaluation, static conventional, and fat saturated T1-weighted sequences. MR datasets were evaluated by 3 independent radiologists. The standard of reference was defined by an independent truth panel (radiologist or hepatologist).The safety evaluation included adverse events, vital signs, and physical examination. RESULTS:: A total of 497 of 572 patients were eligible for the final efficacy analysis. Noninferiority of gadobutrol-enhanced magnetic resonance imaging (MRI) for the classification of liver lesions was demonstrated on the basis of diagnostic accuracy determined by the on-site investigators (-0.098, 0.021) as well as for the average reader of the blinded evaluation (-0.096, 0.014) (95% confidence interval), compared with the predefined standard of reference. Very similar increases in sensitivity (ranging from approximately 10% to approximately 55%) and specificity (ranging from approximately 1%- approximately 18%) compared with precontrast MRI were also observed for the 2 contrast agent groups, with maximum differences of 4%.Very similar, low rates of adverse events were recorded for each of the 2 groups. No clinically relevant changes in vital signs or the results of the physical examination were observed in any patient. CONCLUSION:: This study documents evidence for the noninferiority of a single i.v. bolus injection of 1.0 M gadobutrol (0.1 mmol/kg body weight) to 0.5 M gadopentetate (0.1 mmol/kg body weight) in the diagnostic assessment of liver lesions with contrast-enhanced MRI. The known excellent safety profile of gadobutrol was confirmed in this clinical trial and is similar to that of gadopentetate.

Purpose To evaluate the accuracy of four MR sequences used as part of a whole-body MRI protocol to detect pulmonary lesions in cancer patients. Materials and Methods A total of 31 oncology patients were imaged in a 1.5T MR scanner (Magnetom Avanto; Siemens Medical Solutions, Germany) for whole-body staging. MR chest imaging included: axial and coronal T2-weighted (T2w)–short-tau inversion-recovery (STIR), axial T2w turbo spin-echo (TSE), and contrast-enhanced (CE) three-dimensional (3D) volumetric interpolated breathhold examination (VIBE). Multidetector computed tomography (MDCT) of the thorax served as the reference standard. The MDCT and MR images were evaluated independently by two radiologists. Comparative analysis was performed per lesion, per lobe, and per patient. Sensitivity, specificity, and predictive values were determined. Results Compared to MDCT that detected 268 pulmonary lesions ranging from 2 to 75 mm in diameter, the MR sensitivities were 91.1%, 92.5%, 90.8%, and 87.3% for the coronal STIR, the axial STIR, the axial T2w-TSE, and the axial CE 3D-VIBE, respectively. Undetected pulmonary lesions were either calcified or smaller than 10 mm in the axial diameter. With coronal STIR, six false-positive findings were detected; with axial STIR, 14 were detected; with axial T2w-TSE, 10 were detected; and with 3D-VIBE, seven were detected. Conclusion Pulmonary MRI is feasible as part of a whole-body MRI protocol. In our study, STIR images achieved high accuracy compared to chest MDCT for pulmonary lesions of 3 mm in size or larger. J. Magn. Reson. Imaging 2008. © 2008 Wiley-Liss, Inc.

A major problem of segmentation of magnetic resonance images is that intensities are not standardized like in computed tomography. This article deals with the correction of inter volume intensity differences that lead to a missing anatomical meaning of the observed gray values. We present a method for MRI intensity standardization of whole body MRI scans. The approach is based on the alignment of a learned reference and the current histogram. Each of these histograms is at least 2-d and represents two or more MRI sequences (e.g., T1- and T2-weighted images). From the matching a non-linear correction function is gained which describes a mapping between the intensity spaces and consequently adapts the image statistics to a known standard. As the proposed intensity standardization is based on the statistics of the data sets only, it is independent from spatial coherences or prior segmentations of the reference and newly acquired images. Furthermore, it is not designed for a particular application, body region or acquisition protocol. The method was evaluated on whole body MRI scans containing data sets acquired by T1/FL2D and T2/TIRM sequences. In order to demonstrate the applicability, examples from noisy and pathological image series acquired on a whole body MRI scanner are given.

In a multidisciplinary conference patients with advanced non-resectable hepatocellular carcinoma (HCC) were stratified according to their clinical status and tumor extent to different regional modalities or to best supportive care. The present study evaluated all patients who were stratified to repeated transarterial chemoembolization (TACE) from 1999 until 2003 in terms of tumor response, toxicity, and survival. A moderate embolizing approach was chosen using a combination of degradable starch microspheres (DSM) and iodized oil (Lipiodol) in order to combine anti-tumoral efficiency and low toxicity.Fourty-seven patients were followed up prospectively. TACE treatment consisted of cisplatin (50 mg/m(2)), doxorubicin (50 mg/m(2)), 450-900 mg DSM, and 5-30 ml Lipiodol. DSM and Lipiodol were administered according to tumor vascularization. Patient characteristics, toxicity, and complications were outlined. In multivariate regression analyses of pre-treatment variables from a prospective database, predictors for tumor response and survival after TACE were determined.112 TACE courses were performed (2.4+/-1.5 courses per patient). Mean maximum tumor size was 75 (+/-43) mm, in 68% there was bilobar disease. Best response to TACE treatment was: progressive disease (PD) 9%, stable disease (SD) 55%, partial remission (PR) 36%, and complete remission (CR) 0%. Multivariate regression analyses identified tumor sizeor=75 mm, tumor numberor=5, and tumor hypervascularization as predictors for PR. The overall 1-, 2-, and 3-year-survival rates were 75%, 59%, and 41%, respectively, and the median survival was 26 months. Low alpha-fetoprotein levels (400 ng/ml) (Odds ratio=3.3) and PR as best response to TACE (Odds ratio=6.7) were significantly associated with long term survival (30 months, R(2)=36%). Grade 3 toxicity occurred in 7.1% (n=8), and grade 4 toxicity in 3.6% (n=4) of all courses in terms of reversible leukopenia and thrombocytopenia. The incidence of major complications was 5.4% (n=6). All complications were managed conservatively. The mortality within 6 weeks after TACE was 2.1% (one patient).DSM and Lipiodol were combined successfully in the palliative TACE treatment of advanced HCC resulting in high rates of tumor response and survival at limited toxicity. Favourable tumor response was associated with tumor extent and vascularization. TACE using DSM and Lipiodol can be considered a suitable palliative measure in patients who might not tolerate long acting embolizing agents.

AIM: In nonresectable cholangiocellular carcinoma (CCC) therapeutic options are limited. Recently, systemic chemotherapy has shown response rates of up to 30%. Additional regional therapy of the arterially hyper vascularized hepatic tumors might represent a rational approach in an attempt to further improve response and palliation. Hence, a protocol combining transarterial chemoembolization and systemic chemotherapy was applied in patients with CCC limited to the liver. METHODS: Eight patients (6 women, 2 men, mean age 62 years) with nonresectable CCC received systemic chemotherapy (gemcitabine 1000 mg/m2) and additional transarterial chemoembolization procedures (50 mg/m2 cisplatin, 50 mg/m2 doxorubicin, up to 600 mg degradable starch microspheres). Clinical follow-up of patients, tumor markers, CT and ultrasound were performed to evaluate maximum response and toxicity. RESULTS: Both systemic and regional therapies were tolerated well; no severe toxicity (WHO III/IV) was encountered. Nausea and fever were the most commonly observed side effects. A progressive rarefication of the intrahepatic arteries limited the maximum number of chemoembolization procedures in 4 patients. A median of 2 chemoembolization cycles (range, 1-3) and a median of 6.5 gemcitabine cycles (range, 4-11) were administered. Complete responses were not achieved. As maximum response, partial responses were achieved in 3 cases, stable diseases in 5 cases. Two patients died from progressive disease after 9 and 10 mo. Six patients are still alive. The current median survival is 12 mo (range, 9-18); the median time to tumor progression is 7 mo (range, 3-18). Seven patients suffered from tumor-related symptoms prior to therapy, 3 of these experienced a treatment-related clinical relief. In one patient the tumor became resectable under therapy and was successfully removed after 10 mo. CONCLUSION: The present results indicate that a combination of systemic gemcitabine therapy and repeated regional chemoembolizations is well tolerated and may enhance the effect of palliation in a selected group of patients with intrahepatic nonresectable CCC.

Objective: The oncologically safe application of thermal in-situ ablation techniques is limited by a lack of precise prediction and online monitoring of the resulting destruction. Knowledge about intrahepatic vessel structure is important for therapy planning. The aim of the current study was to validate in-vivo an interdisciplinary developed 3D planning system for the in-situ ablation of liver tumors with regard to intrahepatic vessel segmentation. Methods: 10 domestic pigs were used (40 kg, endotracheal anaesthesia, cross-laparatomy). After surgical preparation of the extra-hepatic vessels, an angiographie catheter was implanted in the portal vein. A computed tomography (CT, Siemens Somatom l6, 1 mm slices, DICOM2 data acquisition) was performed an each pig. The scans were carried out using a peripheral venous contrast medium (CM) and a selective CM-CT via the implanted portal vein catheter. After removal of the liver, a corrosion cast with acrylic resin via the portal vein catheter was prepared in-situ. The image data was transferred to the planning system and the vessel segmentation was carried out. The validation was performed by comparing the corrosion cast and the computed segmentation. Results: A segment classification of the pig liver was established. Standard CTs allowed for segmentation of the portal vein branches down to 3rd degree subsegment vessels. The comparison between the patterns of the corrosion cast and the peripheral veins and selective segmentation showed complete correlation to the 1st degree subsegment vessels and a correlation of 97% to the 2nd degree subsegment vessels. Incorrect segmentations, i.e. assignment of adjacent vessel systems, or aborts of segmentation were not abserved. Conclusions: 1.) A 3D computer planning system was developed for predicting thermal lesions resulting from in-situ ablation. 2.) The algorithms for vessel segmentation resulted in a precise depiction of the in-vivo intrahepatic vessel structure. 3.) This planning system facilitates the calculated use of thermal in-situ ablation techniques.

Background & Aims: VP22-mediated intercellular transport provides an approach to deliver functional chimeric proteins into a high percentage of target cells. The aim of this study was to evaluate the efficacy of p53/VP22 fusion protein in gene therapy of liver tumors. Methods: Expression vectors of N- and C-terminal fusion proteins of p53 and VP22 were subcloned and transcriptional properties of chimeric proteins were assessed by luciferase assays. Adenoviral vectors expressing p53 wild type (AdGFP/p53wt) and p53-VP22 (AdGFP/p53-VP22) were generated to investigate the VP22-mediated spreading in normal liver and in liver tumors in vivo by green fluorescent protein fluorescence and p53 immunohistochemistry. Gene therapy was investigated in subcutaneous and preclinical orthotopic animal tumor models after subcutaneous and intra-arterial administration of the adenoviruses, and tumor growth was assessed by direct calibration and magnetic resonance imaging. Results: p53-VP22 showed enhanced transcriptional activity compared with p53 wild type. VP22-mediated intercellular transport of p53 could be observed in the normal liver and in liver tumors in vivo and was correlated with increased antitumor efficacy of gene therapy and improved survival of the animals. Conclusions: Fusion of VP22 to p53 strongly improves the results of p53 replacement gene therapy. Furthermore, the demonstrated VP22-mediated intercellular transport in the liver could be important for other strategies in liver gene therapy, providing a tool for enhancing the effect of gene therapy in liver diseases such as metabolic disorders or viral hepatitis. GASTROENTEROLOGY 2002;123:608-618

Abstract 593 Background: The international FIT Trial (ASH 2007) had shown that Radioimmunotherapy (RIT) with 90Yttrium Ibritumomab Tiuxetan (Zevalin®) significantly improves the remission rate in follicular lymphoma (FL) if given as consolidation after chemotherapy. Since high remission rates are achieved in combination with both mild and aggressive chemotherapy regimens we asked whether chemotherapy is needed at all before applying RIT. Methods: Previously untreated patients with follicular lymphoma Grade I-IIIA from 7 centers in Austria, Germany, Italy, and Sweden have entered a prospective phase II clinical trial. Patients received 90Yttrium Ibritumomab Tiuxetan at the standard single dose of 15 MBq/kg (0.4 mCi/kg). Only stage III and IV FL patients older than 50 y (as required by radiation safety agency) and with clinical need for treatment (tumor lesions increasing at least 50% in the last 6 months, B-Symptoms, bulky disease up to 10cm) were allowed to enter the protocol. The primary end point was the clinical and molecular remission rate six months after primary treatment with 90Yttrium Ibritumomab Tiuxetan. Secondary end points were time to progression as well as safety and tolerability of 90Yttrium Ibritumomab Tiuxetan. Results: 59 of 60 planned patients have been recruited between July 2007 and June 2010. Treatment was well tolerated without severe acute toxicity and with only grade I-II adverse events. Hematological toxicity was modest: 24 patients exhibit Thrombocytopenia (in one case Grade 4, in 13 cases Grade 3) and Neutropenia, (Grade 3 in 13 cases, no grade 4), Anemia (only grade 1–2) was noticed in 5 patients, other side effects were grade 1 or 2. Febrile episodes were not observed after RIT. At the first follow-up 6 months after RIT 25 patients were in complete remission (45%) and 22 patients were in partial remission (40%) adding up to an ORR of 85%. One year after therapy, the response rate is 72% with 52% CR and 20% PR. Among the 33 patients who have reached a follow up of more than 18 months, 52% continue to stay in complete remission, 9% are still in partial remission while 36% of the patients progressed and are off study, either in observation or with a new treatment. At a median follow-up of 23 months the PFS is 17.9 months. 2 Deaths occurred during observation time, both patients had been off study because of progressive disease: one patient died of progressive lymphoma after several lines of salvage chemotherapy, pancreas carcinoma was the cause of death in a further patient about 10 months after lymphoma progression. While 3 more cases of non-hematological cancers (colon adenocarcinoma, oral cavity squamous carcinoma, renal cancer) were recorded during the study, reevaluation of the CT scans done before RIT revealed in 2 of these patients lesions that were preexisting but missed or misinterpreted as lymphoma. In addition, the short latency between RIT and cancer diagnosis makes a causal relationship unlikely in the remaining two cases. Progression to high-grade lymphoma occurred in 3 patients so far. 49% of the patients (n = 28/57) had evidence of BCL2-IgH translocation in peripheral blood and/or bone marrow by PCR analysis. Of 26 patients evaluated 6 months after treatment 19 have turned negative (molecular remission rate MR = 73%). 9 of these MR patients had only achieved partial remission at clinical evaluation, 3 of them achieved a complete remission later during observation while 3 progressed. Ancillary PET studies were performed in 2 centers including sequential evaluation after therapy. Preliminary evaluation suggests that positivity of PET predicts relapse before this becomes clinically evident. Conclusion: Radioimmunotherapy with 90Yttrium Ibritumomab Tiuxetan was very safe and well accepted by patients, it induces high percentages of both clinical and molecular responses when given as first line treatment to patients with advanced stage follicular lymphoma. Remission rates are similar to those achieved by standard chemoimmunotherapy protocols, but absence of infectious episodes and the limited severity of side effects compares extremely well with the toxicity of chemotherapy regimens. Duration of remission will be a crucial issue for final comparison. Our study suggests first line RIT as a valuable option, particularly for older and/or frail patients with FL in need of therapy. Disclosures: No relevant conflicts of interest to declare.

We present a novel technique to predict the outcome of an RF ablation, including the vascular cooling effect. The main idea is to separate the problem into a patient independent part, which has to be performed only once for every applicator model and generator setting, and a patient dependent part, which can be performed very fast. The patient independent part fills a look-up table of the cooling effects of blood vessels, depending on the vessel radius and the distance of the RF applicator from the vessel, using a numerical simulation of the ablation process. The patient dependent part, on the other hand, only consists of a number of table look-up processes. The paper presents this main idea, along with the required steps for its implementation. First results of the computation and the related ex-vivo evaluation are presented and discussed. The paper concludes with future extensions and improvements of the approach.