Development and Validation of a Language Screening for Implementation in Pre-School Settings.

Background: To prevent or mitigate long-lasting learning problems and emotional, behavioral, and social-adaption difficulties associated with language disorders, age-appropriate German language competence at school entry level is essential. Therefore, universal screening of children in their penultimate year of pre-school has been established in Upper Austria. So far, the screenings administered by speech and language pathologists to identify risk of language disorder (LD) were not based on standardized materials. Objective: To develop a screening instrument to identify increased risk of LD and to evaluate its validity and feasibility within the constraints of regular universal pre-school language screening. Design: A two-component screening instrument including direct assessment of expressive and receptive grammar was used in a sample of 374 children with German as their dominant language attending a public pre-school in their penultimate year (age 4-5 ½ years) in the state of Upper Austria. Assessment by use of standardized German language tests including a variety of linguistic domains was considered reference standard for diagnosing LD. Feasibility was assessed by a self-developed questionnaire completed by the administrators of the screening. Results: The combination of the expressive and receptive grammar scales demonstrated excellent accuracy (area under the curve score 0.928). A cut-off of 18 resulted in a failing rate of 21.8% and showed good sensitivity (84.2%) and specificity (85.3%). Acceptance by children and testers, time-economy and sustainability of the screening were mostly rated as high.

Prevalence of colorectal cancer and its precursor lesions in symptomatic patients under 55 years of age undergoing total colonoscopy: results of a large retrospective, multicenter, controlled endoscopy study.

PURPOSE: Colorectal cancer (CRC) is the second most common cancer in Germany. Around 60,000 people were diagnosed CRC in 2016 in Germany. Since 2019, screening colonoscopies are offered in Germany for men by the age of 50 and for women by the age of 55. It is recently discussed if women should also undergo a screening colonoscopy by the age of 50 and if there are any predictors for getting CRC. METHODS: Colonoscopies of 1553 symptomatic patients younger than 55 years were compared with colonoscopies of 1075 symptomatic patients older than 55 years. We analyzed if there are any significant differences between those two groups in the prevalence of CRC and its precursor lesions or between symptomatic men and women. We evaluated if there is a correlation between abdominal symptoms and the prevalence of CRC. RESULTS: In 164/1553 symptomatic patients, 194 (12.5%) polyps were detected. In total, six colorectal carcinomas (0.4%) were detected. There were no significant differences between men and women. In symptomatic patients ≥ 55 years, significantly more polyps were found (p<0.0001; 26.6% vs. 12.5%). Totally, 286 polyps (26.6%) were removed in 1075 symptomatic patients older than 55 years. Anorectal bleeding was the only abdominal symptom being a significant indicator for the prevalence of the occurrence of colon and rectum cancer in both groups (p=0.03, OR=2.73 95%-CI [1.11;6.70]), but with only low sensitivity (44%). CONCLUSION: Due to no significant differences in men and women, we recommend screening colonoscopies also for women by the age of 50.

Protein-only RNase P function in Escherichia coli: viability, processing defects and differences between PRORP isoenzymes.

The RNase P family comprises structurally diverse endoribonucleases ranging from complex ribonucleoproteins to single polypeptides. We show that the organellar (AtPRORP1) and the two nuclear (AtPRORP2,3) single-polypeptide RNase P isoenzymes from Arabidopsis thaliana confer viability to Escherichia coli cells with a lethal knockdown of its endogenous RNA-based RNase P. RNA-Seq revealed that AtPRORP1, compared with bacterial RNase P or AtPRORP3, cleaves several precursor tRNAs (pre-tRNAs) aberrantly in E. coli. Aberrant cleavage by AtPRORP1 was mainly observed for pre-tRNAs that can form short acceptor-stem extensions involving G:C base pairs, including tRNAAsp(GUC), tRNASer(CGA) and tRNAHis. However, both AtPRORP1 and 3 were defective in processing of E. coli pre-tRNASec carrying an acceptor stem expanded by three G:C base pairs. Instead, pre-tRNASec was degraded, suggesting that tRNASec is dispensable for E. coli under laboratory conditions. AtPRORP1, 2 and 3 are also essentially unable to process the primary transcript of 4.5S RNA, a hairpin-like non-tRNA substrate processed by E. coli RNase P, indicating that PRORP enzymes have a narrower, more tRNA-centric substrate spectrum than bacterial RNA-based RNase P enzymes. The cells' viability also suggests that the essential function of the signal recognition particle can be maintained with a 5΄-extended 4.5S RNA.

Reduced Incidence of Thromboembolic Events After Surgical Closure of Left Atrial Appendage in Patients With Atrial Fibrillation.

OBJECTIVE: Most of the detected thrombi in patients with atrial fibrillation (AF) can be found in the left atrial appendage (LAA). Interventional LAA closure recently proved to be noninferior to warfarin therapy. Whether these results can be fully translated into surgical LAA closure remains unclear. Corresponding data are still lacking. The present observational study evaluated the impact of surgical LAA closure in patients with AF undergoing cardiac surgery on postoperative thromboembolic events. METHODS: A prospective registry enrolled 398 patients with permanent AF undergoing cardiac surgery. Concomitant procedures were isolated surgical ablation (group I, n = 71), isolated LAA closure (group II, n = 44), and combined surgical ablation and LAA closure (group III, n = 196). The control group consisted of 87 patients without concomitant surgical ablation or LAA closure. One-year follow-up was completed in all patients. End points were thromboembolic events and death from any cause. RESULTS: Clinical baseline characteristics were comparable among the groups. General hospital mortality was 5.5% and likewise differed not significantly. Postoperatively, mean (SD) CHAD2S2-VASc score of 3.5 (1.3) differed not significantly among the groups, indicating comparable thromboembolic risk. Follow-up referred to all hospital survivors (n = 376). Herein, overall incidence of thromboembolic events was 9.8% (n = 37), with an associated mortality of 41.0%. Patients with LAA closure alone or in combination with surgical ablation had a significantly reduced incidence of thromboembolic events (6.6% vs 20.5%, P < 0.01) and consecutively improved survival after 1 year of follow-up (7.0% vs 17.1%, P < 0.01). CONCLUSIONS: Left atrial appendage closure alone or in combination with surgical ablation was associated with a significantly reduced rate of thromboembolic events and consecutively improved survival after 1 year of follow-up.

Rupture of a spinal dermoid cyst may lead to dissemination and progress of Fatty tissue in the central spinal canal and intracranial subarachnoid space. A case report.

Intradural dermoid cysts may rupture and subsequent subarachnoid dissemination of lipid droplets has been described before. However, the rupture of a spinal dermoid cyst into the central spinal canal is a rare entity. In this context, dissemination of fat into the intracranial subarachnoid space with local progression is a peculiar finding that, to the best of our knowledge, has not been published so far. We describe the case of a 28-year-old man with a dermoid cyst at the upper lumbar level as part of a complex congenital craniospinal malformation, presenting with new unspecific neurologic symptoms. CT and MRI revealed disseminated intraventricular and subarachnoid lipid droplets intracranially and in the spine not present on previous CT and MRI scans obtained eight years earlier. Thus, repeated rupture of a spinal dermoid cyst with subarachnoid spread and/or secondary proliferation should be suspected.

Playing RNase P evolution: swapping the RNA catalyst for a protein reveals functional uniformity of highly divergent enzyme forms.

The RNase P family is a diverse group of endonucleases responsible for the removal of 5' extensions from tRNA precursors. The diversity of enzyme forms finds its extremes in the eukaryal nucleus where RNA-based catalysis by complex ribonucleoproteins in some organisms contrasts with single-polypeptide enzymes in others. Such structural contrast suggests associated functional differences, and the complexity of the ribonucleoprotein was indeed proposed to broaden the enzyme's functionality beyond tRNA processing. To explore functional overlap and differences between most divergent forms of RNase P, we replaced the nuclear RNase P of Saccharomyces cerevisiae, a 10-subunit ribonucleoprotein, with Arabidopsis thaliana PRORP3, a single monomeric protein. Surprisingly, the RNase P-swapped yeast strains were viable, displayed essentially unimpaired growth under a wide variety of conditions, and, in a certain genetic background, their fitness even slightly exceeded that of the wild type. The molecular analysis of the RNase P-swapped strains showed a minor disturbance in tRNA metabolism, but did not point to any RNase P substrates or functions beyond that. Altogether, these results indicate the full functional exchangeability of the highly dissimilar enzymes. Our study thereby establishes the RNase P family, with its combination of structural diversity and functional uniformity, as an extreme case of convergent evolution. It moreover suggests that the apparently gratuitous complexity of some RNase P forms is the result of constructive neutral evolution rather than reflecting increased functional versatility.

Comparative diagnostic performance of ¹8F-FDG PET/CT versus whole-body MRI for determination of remission status in multiple myeloma after stem cell transplantation.

OBJECTIVES: To compare the diagnostic performance of whole-body magnetic resonance imaging (WBMRI) versus (18)F-fluorodeoxyglucose ((18)F-FDG) positron emission tomography/computed tomography (PET/CT) for determination of remission status in patients with multiple myeloma (MM) after stem cell transplantation (SCT). METHODS: Thirty-one patients were examined by both WBMRI and PET/CT after SCT. Imaging results and clinical remission status as determined by the clinical gold standard (Uniform Response Criteria) were compared. RESULTS: One hundred four lesions were detected in 21 patients. PET/CT had a sensitivity of 50.0 %, a specificity of 85.7 %, a positive predictive value of 62.5 %, a negative predictive value of 78.3 %, and an overall accuracy of 74.2 % for determination of remission status. MRI had a sensitivity of 80.0 %, a specificity of 38.1 %, a positive predictive value of 38.1 %, a negative predictive value of 80 %, and an overall accuracy of 51.6 %. Concordant results were observed in only 12 (11.5 %) of the 104 lesions. CONCLUSIONS: In the post-treatment setting, both FDG PET/CT and WBMRI provide information about the extent of disease, allowing for a more comprehensive evaluation of persisting or recurrent myeloma. MRI may often be false positive because of persistent non-viable lesions. Therefore, PET/CT might be more suitable than MRI for determination of remission status.

tRNA processing by protein-only versus RNA-based RNase P: kinetic analysis reveals mechanistic differences.

In Arabidopsis thaliana, RNase P function, that is, endonucleolytic tRNA 5'-end maturation, is carried out by three homologous polypeptides ("proteinaceous RNase P" (PRORP) 1, 2 and 3). Here we present the first kinetic analysis of these enzymes. For PRORP1, a specificity constant (k(react)/K(m(sto))) of 3×10(6) M(-1) min(-1) was determined under single-turnover conditions. We demonstrate a fundamentally different sensitivity of PRORP enzymes to an Rp-phosphorothioate modification at the canonical cleavage site in a 5'-precursor tRNA substrate; whereas processing by bacterial RNase P is inhibited by three orders of magnitude in the presence of this sulfur substitution and Mg(2+) as the metal-ion cofactor, the PRORP enzymes are affected by not more than a factor of five under the same conditions, without significantly increased miscleavage. These findings indicate that the catalytic mechanism utilized by proteinaceous RNase P is different from that of RNA-based bacterial RNase P, taking place without a direct metal-ion coordination to the (pro-)Rp substituent. As Rp-phosphorothioate and inosine modification at all 26 G residues of the tRNA body had only minor effects on processing by PRORP, we conclude that productive PRORP-substrate interaction is not critically dependent on any of the affected (pro-)Rp oxygens or guanosine 2-amino groups.

Diagnostic performance of whole-body MRI for the detection of persistent or relapsing disease in multiple myeloma after stem cell transplantation.

OBJECTIVES: To compare the diagnostic performance of whole-body MRI (WBMRI) with haematological parameters for detecting persistent or relapsing disease in patients with multiple myeloma after stem cell transplantation. METHODS: Sixty-six WBMRI acquisitions were performed in 33 patients with multiple myeloma at two time points after stem cell transplantation. Extent of disease and inter-test dynamics of intra- and extramedullary myeloma manifestations were compared (kappa statistics) with Uniform Response Criteria, comprising haematological parameters. RESULTS: Using data from 66 sequential WBMRI acquisitions in 33 patients, 10 patients (30.3 %) were classified as having progressive disease and 23 (69.7 %) as being in remission. Eight (80 %) of the ten patients with progressive disease revealed intramedullary lesions, and two patients (20 %) had intra- and extramedullary lesions. WBMRI and laboratory tests were concordant in 26/33 (78.8 %) patients. We found an agreement of 51.2 %, 95 % confidence interval 19.8 %-82.6 %, between results from WBMRI and haematological parameters. WBMRI had a sensitivity of 63.6 %, specificity of 86.4 %, PPV of 70.0 %, NPV of 82.6 % and accuracy of 78.8 % for detection of remission. CONCLUSIONS: WBMRI allows the detection and exact localisation of intra- and extramedullary myeloma manifestations after stem cell transplantation, but shows only moderate agreement with routinely performed laboratory tests for determination of remission.

High-performance GPU-based rendering for real-time, rigid 2D/3D-image registration and motion prediction in radiation oncology.

A common problem in image-guided radiation therapy (IGRT) of lung cancer as well as other malignant diseases is the compensation of periodic and aperiodic motion during dose delivery. Modern systems for image-guided radiation oncology allow for the acquisition of cone-beam computed tomography data in the treatment room as well as the acquisition of planar radiographs during the treatment. A mid-term research goal is the compensation of tumor target volume motion by 2D/3D Registration. In 2D/3D registration, spatial information on organ location is derived by an iterative comparison of perspective volume renderings, so-called digitally rendered radiographs (DRR) from computed tomography volume data, and planar reference x-rays. Currently, this rendering process is very time consuming, and real-time registration, which should at least provide data on organ position in less than a second, has not come into existence. We present two GPU-based rendering algorithms which generate a DRR of 512×512 pixels size from a CT dataset of 53 MB size at a pace of almost 100 Hz. This rendering rate is feasible by applying a number of algorithmic simplifications which range from alternative volume-driven rendering approaches - namely so-called wobbled splatting - to sub-sampling of the DRR-image by means of specialized raycasting techniques. Furthermore, general purpose graphics processing unit (GPGPU) programming paradigms were consequently utilized. Rendering quality and performance as well as the influence on the quality and performance of the overall registration process were measured and analyzed in detail. The results show that both methods are competitive and pave the way for fast motion compensation by rigid and possibly even non-rigid 2D/3D registration and, beyond that, adaptive filtering of motion models in IGRT.

Dual phosphoproteomics and chemical proteomics analysis of erlotinib and gefitinib interference in acute myeloid leukemia cells.

Small molecule inhibitors of protein kinases have emerged as a major class of therapeutic agents for the treatment of hematological malignancies. Both in vitro studies and patient case reports suggest therapeutic potential of the clinical kinase inhibitors erlotinib and gefitinib in acute myeloid leukemia (AML). The drugs' cellular modes of action in AML warrant further investigation as their primary therapeutic target, the epidermal growth factor receptor, is not expressed. We therefore performed SILAC-based quantitative mass spectrometry analyses to a depth of 10,975 distinct phosphorylation sites to characterize the phosphoproteome of KG1 AML cells and its regulation upon erlotinib and gefitinib treatment. Less than 50 site-specific phosphorylations changed significantly, indicating rather specific interference with AML cell signaling. Many drug-induced changes occurred within a network of tyrosine phosphorylated proteins that included Src family kinases (SFKs) and the tyrosine kinases Btk and Syk. We further performed quantitative chemical proteomics in KG1 cell extracts and identified SFKs and Btk as direct cellular targets of both erlotinib and gefitinib. Taken together, our data suggest that cellular perturbation of SFKs and/or Btk translates into rather specific signal transduction inhibition, which in turn contributes to the antileukemic activity of erlotinib and gefitinib in AML.

18F-FDG PET/CT for detection and localization of residual or recurrent disease in patients with multiple myeloma after stem cell transplantation.

PURPOSE: The aim of the study was to determine the diagnostic performance of (18)F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/CT for the detection and localization of residual or recurrent disease in patients with multiple myeloma (MM) after stem cell transplantation. METHODS: A total of 197 whole-body (18)F-FDG PET/CT scans were performed in 99 patients with MM at different time points in the course of disease after autologous or allogeneic stem cell transplantation. Post-transplant PET/CT scans and clinical remission status as determined by the clinical gold standard (Uniform Response Criteria) were analysed and compared. RESULTS: A total of 576 focal osseous and extramedullary lesions were detected in 79 scans. Additional diffuse bone marrow involvement was detected in 17 patients. (18)F-FDG PET/CT had a sensitivity of 54.6%, a specificity of 82.1%, a positive predictive value of 82.3%, a negative predictive value of 54.2% and an overall accuracy of 65.5%. The sensitivity of (18)F-FDG PET/CT was shown to depend on the disease category according to the Uniform Response Criteria for myeloma. CONCLUSION: In patients with MM in the post-transplant setting, (18)F-FDG PET/CT may (1) contribute to the detection and localization of disease, (2) provide information about the extent of distinct myeloma manifestations and the total disease burden and (3) add information about the metabolic activity of disease, but (4) has substantially lower sensitivity for this purpose compared to the pretreatment setting.

Monitoring tumor motion by real time 2D/3D registration during radiotherapy.

BACKGROUND AND PURPOSE: In this paper, we investigate the possibility to use X-ray based real time 2D/3D registration for non-invasive tumor motion monitoring during radiotherapy. MATERIALS AND METHODS: The 2D/3D registration scheme is implemented using general purpose computation on graphics hardware (GPGPU) programming techniques and several algorithmic refinements in the registration process. Validation is conducted off-line using a phantom and five clinical patient data sets. The registration is performed on a region of interest (ROI) centered around the planned target volume (PTV). RESULTS: The phantom motion is measured with an rms error of 2.56 mm. For the patient data sets, a sinusoidal movement that clearly correlates to the breathing cycle is shown. Videos show a good match between X-ray and digitally reconstructed radiographs (DRR) displacement. Mean registration time is 0.5 s. CONCLUSIONS: We have demonstrated that real-time organ motion monitoring using image based markerless registration is feasible.

Splint sterilization--a potential registration hazard in computer-assisted surgery.

PURPOSE: Registration of preoperative targeting information for the intraoperative situation is a crucial step in computer-assisted surgical interventions. Point-to-point registration using acrylic splints is among the most frequently used procedures. There are, however, no generally accepted recommendations for sterilization of the splint. An appropriate method for the thermolabile splint would be hydrogen peroxide-based plasma sterilization. This study evaluated the potential deformation of the splint undergoing such sterilization. Deformation was quantified using image-processing methods applied to computed tomographic (CT) volumes before and after sterilization. MATERIALS AND METHODS: An acrylic navigation splint was used as the study object. Eight metallic markers placed in the splint were used for registration. Six steel spheres in the mouthpiece were used as targets. Two CT volumes of the splint were acquired before and after 5 sterilization cycles using a hydrogen peroxide sterilizer. Point-to-point registration was applied, and fiducial and target registration errors were computed. Surfaces were extracted from CT scans and Hausdorff distances were derived. Effectiveness of sterilization was determined using Geobacillus stearothermophilus. RESULTS: Fiducial-based registration of CT scans before and after sterilization resulted in a mean fiducial registration error of 0.74 mm; the target registration error in the mouthpiece was 0.15 mm. The Hausdorff distance, describing the maximal deformation of the splint, was 2.51 mm. Ninety percent of point-surface distances were shorter than 0.61 mm, and 95% were shorter than 0.73 mm. No bacterial growth was found after the sterilization process. CONCLUSION: Hydrogen peroxide-based low-temperature plasma sterilization does not deform the splint, which is the base for correct computer-navigated surgery.

Validation for 2D/3D registration. II: The comparison of intensity- and gradient-based merit functions using a new gold standard data set.

PURPOSE: A new gold standard data set for validation of 2D/3D registration based on a porcine cadaver head with attached fiducial markers was presented in the first part of this article. The advantage of this new phantom is the large amount of soft tissue, which simulates realistic conditions for registration. This article tests the performance of intensity- and gradient-based algorithms for 2D/3D registration using the new phantom data set. METHODS: Intensity-based methods with four merit functions, namely, cross correlation, rank correlation, correlation ratio, and mutual information (MI), and two gradient-based algorithms, the backprojection gradient-based (BGB) registration method and the reconstruction gradient-based (RGB) registration method, were compared. Four volumes consisting of CBCT with two fields of view, 64 slice multidetector CT, and magnetic resonance-T1 weighted images were registered to a pair of kV x-ray images and a pair of MV images. A standardized evaluation methodology was employed. Targets were evenly spread over the volumes and 250 starting positions of the 3D volumes with initial displacements of up to 25 mm from the gold standard position were calculated. After the registration, the displacement from the gold standard was retrieved and the root mean square (RMS), mean, and standard deviation mean target registration errors (mTREs) over 250 registrations were derived. Additionally, the following merit properties were computed: Accuracy, capture range, number of minima, risk of nonconvergence, and distinctiveness of optimum for better comparison of the robustness of each merit. RESULTS: Among the merit functions used for the intensity-based method, MI reached the best accuracy with an RMS mTRE down to 1.30 mm. Furthermore, it was the only merit function that could accurately register the CT to the kV x rays with the presence of tissue deformation. As for the gradient-based methods, BGB and RGB methods achieved subvoxel accuracy (RMS mTRE down to 0.56 and 0.70 mm, respectively). Overall, gradient-based similarity measures were found to be substantially more accurate than intensity-based methods and could cope with soft tissue deformation and enabled also accurate registrations of the MR-T1 volume to the kV x-ray image. CONCLUSIONS: In this article, the authors demonstrate the usefulness of a new phantom image data set for the evaluation of 2D/3D registration methods, which featured soft tissue deformation. The author's evaluation shows that gradient-based methods are more accurate than intensity-based methods, especially when soft tissue deformation is present. However, the current nonoptimized implementations make them prohibitively slow for practical applications. On the other hand, the speed of the intensity-based method renders these more suitable for clinical use, while the accuracy is still competitive.

In vivo imaging of mineral deposition in carotid plaque using 18F-sodium fluoride PET/CT: correlation with atherogenic risk factors.

UNLABELLED: The purpose of this study was to correlate (18)F-sodium fluoride accumulation in the common carotid arteries of neurologically asymptomatic patients with cardiovascular risk factors and carotid calcified plaque burden. METHODS: Two hundred sixty-nine oncologic patients were examined by (18)F-sodium fluoride PET/CT. Tracer accumulation in the common carotid arteries was analyzed both qualitatively and semiquantitatively by measuring the blood-pool-corrected standardized uptake value (target-to-background ratio) and comparing it with cardiovascular risk factors and calcified plaque burden. RESULTS: (18)F-sodium fluoride uptake was observed at 141 sites in 94 (34.9%) patients. Radiotracer accumulation was colocalized with calcification in all atherosclerotic lesions. (18)F-sodium fluoride uptake was significantly associated with age (P < 0.0001), male sex (P < 0.0001), hypertension (P < 0.002), and hypercholesterolemia (P < 0.05). The presence of calcified plaque correlated significantly with these risk factors but also with diabetes (P < 0.0001), history of smoking (P = 0.03), and prior cardiovascular events (P < 0.01). There was a highly significant correlation between the presence of (18)F-sodium fluoride uptake and number of present cardiovascular risk factors (r = 0.30, P < 0.0001). CONCLUSION: Carotid (18)F-sodium fluoride uptake is a surrogate measure of calcifying carotid plaque, correlates with cardiovascular risk factors, and is more frequent in patients with a high-risk profile for atherothrombotic events but demonstrates a weaker correlation with risk factors than does calcified plaque burden. This study provides a rationale to conduct further prospective studies to determine whether (18)F-sodium fluoride uptake can predict vascular events, or if it may be used to monitor pharmacologic therapy.

Contrast-enhanced [(18)F]fluorodeoxyglucose-positron emission tomography/computed tomography for staging and radiotherapy planning in patients with anal cancer.

PURPOSE: The practice of surgical staging and treatment of anal cancer has been replaced by noninvasive staging and combined modality therapy. For appropriate patient management, accurate lymph node staging is crucial. The present study evaluated the feasibility and diagnostic accuracy of contrast-enhanced [(18)F]fluoro-2-deoxy-d-glucose ([(18)F]FDG)-positron emission tomography/computed tomography (PET/CT) for staging and radiotherapy planning of anal cancer. METHODS AND MATERIALS: A total of 22 consecutive patients (median age, 61 years old) with anal cancer underwent complete staging evaluation including physical examination, biopsy of the primary tumor, and contrast-enhanced (ce)-PET/CT. Patients were positioned as they would be for their subsequent radiotherapy. PET and CT images were evaluated independently for detectability and localization of the primary tumor, pelvic and inguinal lymph nodes, and distant metastasis. The stage, determined by CT or PET alone, and the proposed therapy planning were compared with the stage and management determined by ce-PET/CT. Data from ce-PET/CT were used for radiotherapy planning. RESULTS: ce-PET/CT revealed locoregional lymph node metastasis in 11 of 22 patients (50%). After simultaneous reading of PET and CT data sets by experienced observers, 3 patients (14%) were found to have sites of disease not seen on CT that were identified on PET. Two patients had sites of disease not seen on PET that were identified on CT. In summary, 2 patients were upstaged, and 4 patients were downstaged due to ce-PET/CT. However, radiotherapy fields were changed due to the results from ce-PET/CT in 23% of cases compared to CT or PET results alone. CONCLUSIONS: ce-PET/CT is superior to PET or CT alone for staging of anal cancer, with significant impact on therapy planning.

18F-FDG-PET/CT in the diagnosis of paraneoplastic neurological syndromes: a retrospective analysis.

OBJECTIVES: Paraneoplastic neurological syndromes (PNS) constitute a challenging diagnostic problem, as the underlying tumour often remains unidentified for a long time, even with frequent conventional diagnostic procedures. For appropriate patient management timely identification of the tumour is critical. We evaluated the value of (18)F-FDG-PET/CT in the investigation of PNS. METHODS: The case notes of 46 consecutive patients with clinically suspected PNS who underwent (18)F-FDG-PET/CT were reviewed retrospectively and the performance of PET/CT for detecting underlying tumours was assessed. RESULTS: PET/CT detected foci of increased (18)F-FDG uptake in 10 out of 46 patients. In six of these 10 patients combined PET/CT identified the underlying disease: four patients suffered from PNS; vasculitic and local metastatic disease was detected in two other patients. CONCLUSIONS: Based on our results, we believe that the role of positron emission tomography in the detection of occult neoplasms in patients with PNS has been overestimated in the past. In clinical practice, PNS is far more often suspected than proven. In our study combined PET/CT identified malignancy as the underlying cause of suspected PNS in only 8.7% (4/46). We believe that combined PET/CT should be reserved for stringently selected patients with a high clinical index of suspicion for PNS and after conventional imaging techniques fail to detect a tumour.

The use of navigation (BrainLAB Vector vision(2)) and intraoperative 3D imaging system (Siemens Arcadis Orbic 3D) in the treatment of gunshot wounds of the maxillofacial region.

PURPOSE: Gunshot wounds are a rare occurrence during times of peace. The removal of projectiles is recommended; in some cases, however, this is a controversy. The reproduction of a projectile image can be difficult if it is not adjacent to an anatomical landmark. Therefore, navigation systems give the surgeon continuous real-time orientation intraoperatively. The aim of this study was to report our experiences for image-guided removal of projectiles and the resulting intra- and postoperative complications. PATIENTS AND METHODS: We investigated 50 patients retrospectively; 32 had image-guided surgical removal of projectiles in the oral and maxillofacial region. Eighteen had surgical removal of projectiles without navigation assistance. RESULTS: There was a significant correlation (p = 0.0136) between the navigated surgery vs. not-navigated surgery and complication rate, including major bleeding (n = 4 vs. n = 1, 8% vs. 2%), soft tissue infections (n = 7 vs. n = 2, 14% vs. 4%), and nerval damage (n = 2 vs. n = 0, 4% vs. 0%; p = 0.038) and between the operating time and postoperative complications. A high tendency between operating time and navigated surgery (p = 0.1103) was shown. When using navigation system, we could reduce operating time. CONCLUSION: In conclusion, there is a significant correlation between reduced intra- and postoperative complications, including wound infections, nerval damage, and major bleeding, and the appropriate use of a navigation system. In all these cases, we could present reduced operating time. Cone-beam computed tomography plays an important role in detecting projectiles or metallic foreign bodies intraoperatively.