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Purpose: To investigate the effect of respiratory motion in terms of signal loss in prostate diffusion-weighted imaging (DWI), and to evaluate the usage of partial Fourier in a free-breathing protocol in a clinically relevant b-value range using both single-shot and multi-shot acquisitions. Methods: A controlled breathing DWI acquisition was first employed at 3 T to measure signal loss from deep breathing patterns. Single-shot and multi-shot (2-shot) acquisitions without partial Fourier (no pF) and with partial Fourier (pF) factors of 0.75 and 0.65 were employed in a free-breathing protocol. The apparent SNR and ADC values were evaluated in 10 healthy subjects to measure if low pF factors caused low apparent SNR or overestimated ADC. Results: Controlled breathing experiments showed a difference in signal coefficient of variation between shallow and deep breathing. In free-breathing single-shot acquisitions, the pF 0.65 scan showed a significantly (p < 0.05) higher apparent SNR than pF 0.75 and no pF in the peripheral zone (PZ) of the prostate. In the multi-shot acquisitions in the PZ, pF 0.75 had a significantly higher apparent SNR than 0.65 pF and no pF. The single-shot pF 0.65 scan had a significantly lower ADC than single-shot no pF. Conclusion: Deep breathing patterns can cause intravoxel dephasing in prostate DWI. For single-shot acquisitions at a b-value of 800 s/mm2, any potential risks of motion-related artefacts at low pF factors (pF 0.65) were outweighed by the increase in signal from a lower TE, as shown by the increase in apparent SNR. In multi-shot acquisitions however, the minimum pF factor should be larger, as shown by the lower apparent SNR at low pF factors. [ABSTRACT FROM AUTHOR]

Cardiac motion causes unpredictable signal loss in respiratory-triggered diffusion-weighted magnetic resonance imaging (DWI) of the liver, especially inside the left lobe. The left liver lobe may thus be frequently neglected in the clinical evaluation of liver DWI. In this work, a data-driven algorithm that relies on the statistics of the signal in the left liver lobe to mitigate the motion-induced signal loss is presented. The proposed data-driven algorithm utilizes the exclusion of severely corrupted images with subsequent spatially dependent image scaling based on a signal-loss model to correctly combine the multi-average diffusion-weighted images. The signal in the left liver lobe is restored and the liver signal is more homogeneous after applying the proposed algorithm. Furthermore, overestimation of the apparent diffusion coefficient (ADC) in the left liver lobe is reduced. The proposed algorithm can therefore contribute to reduce the motion-induced bias in DWI of the liver and help to increase the diagnostic value of DWI in the left liver lobe. [ABSTRACT FROM AUTHOR]

Objectives: To examine the effect of high-b-value computed diffusion-weighted imaging (cDWI) on solid lesion detection and classification in pancreatic intraductal papillary mucinous neoplasm (IPMN), using endoscopic ultrasound (EUS) and histopathology as a standard of reference. Methods: Eighty-two patients with known or suspected IPMN were retrospectively enrolled. Computed high-b-value images at b = 1000 s/mm2 were calculated from standard (b = 0, 50, 300, and 600 s/mm2) DWI images for conventional full field-of-view (fFOV, 3 × 3 × 4 mm3 voxel size) DWI. A subset of 39 patients received additional high-resolution reduced-field-of-view (rFOV, 2.5 × 2.5 × 3 mm3 voxel size) DWI. In this cohort, rFOV cDWI was compared against fFOV cDWI additionally. Two experienced radiologists evaluated (Likert scale 1–4) image quality (overall image quality, lesion detection and delineation, fluid suppression within the lesion). In addition, quantitative image parameters (apparent signal-to-noise ratio (aSNR), apparent contrast-to-noise ratio (aCNR), contrast ratio (CR)) were assessed. Diagnostic confidence regarding the presence/absence of diffusion-restricted solid nodules was assessed in an additional reader study. Results: High-b-value cDWI at b = 1000 s/mm2 outperformed acquired DWI at b = 600 s/mm2 regarding lesion detection, fluid suppression, aCNR, CR, and lesion classification (p = <.001–.002). Comparing cDWI from fFOV and rFOV revealed higher image quality in high-resolution rFOV-DWI compared to conventional fFOV-DWI (p ≤.001–.018). High-b-value cDWI images were rated non-inferior to directly acquired high-b-value DWI images (p =.095–.655). Conclusions: High-b-value cDWI may improve the detection and classification of solid lesions in IPMN. Combining high-resolution imaging and high-b-value cDWI may further increase diagnostic precision. Clinical relevance statement: This study shows the potential of computed high-resolution high-sensitivity diffusion-weighted magnetic resonance imaging for solid lesion detection in pancreatic intraductal papillary mucinous neoplasia (IPMN). The technique may enable early cancer detection in patients under surveillance. Key Points: • Computed high-b-value diffusion-weighted imaging (cDWI) may improve the detection and classification of intraductal papillary mucinous neoplasms (IPMN) of the pancreas. • cDWI calculated from high-resolution imaging increases diagnostic precision compared to cDWI calculated from conventional-resolution imaging. • cDWI has the potential to strengthen the role of MRI for screening and surveillance of IPMN, particularly in view of the rising incidence of IPMNs combined with now more conservative therapeutic approaches. [ABSTRACT FROM AUTHOR]

Objectives: Previous trial results suggest that only a small number of patients with non-metastatic renal cell carcinoma (RCC) benefit from adjuvant therapy. We assessed whether the addition of CT-based radiomics to established clinico-pathological biomarkers improves recurrence risk prediction for adjuvant treatment decisions. Methods: This retrospective study included 453 patients with non-metastatic RCC undergoing nephrectomy. Cox models were trained to predict disease-free survival (DFS) using post-operative biomarkers (age, stage, tumor size and grade) with and without radiomics selected on pre-operative CT. Models were assessed using C-statistic, calibration, and decision curve analyses (repeated tenfold cross-validation). Results: At multivariable analysis, one of four selected radiomic features (wavelet-HHL_glcm_ClusterShade) was prognostic for DFS with an adjusted hazard ratio (HR) of 0.44 (p = 0.02), along with American Joint Committee on Cancer (AJCC) stage group (III versus I, HR 2.90; p = 0.002), grade 4 (versus grade 1, HR 8.90; p = 0.001), age (per 10 years HR 1.29; p = 0.03), and tumor size (per cm HR 1.13; p = 0.003). The discriminatory ability of the combined clinical-radiomic model (C = 0.80) was superior to that of the clinical model (C = 0.78; p < 0.001). Decision curve analysis revealed a net benefit of the combined model when used for adjuvant treatment decisions. At an exemplary threshold probability of ≥ 25% for disease recurrence within 5 years, using the combined versus the clinical model was equivalent to treating 9 additional patients (per 1000 assessed) who would recur without treatment (i.e., true-positive predictions) with no increase in false-positive predictions. Conclusion: Adding CT-based radiomic features to established prognostic biomarkers improved post-operative recurrence risk assessment in our internal validation study and may help guide decisions regarding adjuvant therapy. Key Points: In patients with non-metastatic renal cell carcinoma undergoing nephrectomy, CT-based radiomics combined with established clinical and pathological biomarkers improved recurrence risk assessment. Compared to a clinical base model, the combined risk model enabled superior clinical utility if used to guide decisions on adjuvant treatment. [ABSTRACT FROM AUTHOR]

We present a method to solve a special class of parameter identification problems for an elliptic optimal control problem to global optimality. The bilevel problem is reformulated via the optimal-value function of the lower-level problem. The reformulated problem is nonconvex and standard regularity conditions like Robinson's CQ are violated. Via a relaxation of the constraints, the problem can be decomposed into a family of convex problems and this is the basis for a solution algorithm. The convergence properties are analyzed. It is shown that a penalty method can be employed to solve this family of problems while maintaining convergence speed. For an example problem, the use of the identity as penalty function allows for the solution by a semismooth Newton method. Numerical results are presented. Difficulties and limitations of our approach to solve a nonconvex problem to global optimality are discussed. [ABSTRACT FROM AUTHOR]

Active surveillance (AS) is now included in all major guidelines for patients with low-risk PCa and selected patients with intermediate-risk PCa. Several studies have highlighted the potential benefit of multiparametric magnetic resonance imaging (mpMRI) in AS and it has been adopted in some guidelines. However, uncertainty remains about whether serial mpMRI can help to safely reduce the number of required repeat biopsies under AS. In 2017, the European School of Oncology initiated the Prostate Cancer Radiological Estimation of Change in Sequential Evaluation (PRECISE) panel which proposed the PRECISE scoring system to assess the likelihood of radiological tumor progression on serial mpMRI. The PRECISE scoring system remains the only major system evaluated in multiple publications. In this review article, we discuss the current body of literature investigating the application of PRECISE as it is not as yet an established standard in mpMRI reporting. We delineate the strengths of PRECISE and its potential added value. Also, we underline potential weaknesses of the PRECISE scoring system, which might be tackled in future versions to further increase its value in AS. [ABSTRACT FROM AUTHOR]

Trimalleolar ankle fractures show a bimodal age distribution, affecting younger men and older women. Postmenopausal women often exhibit low bone mineral density, which contributes to a higher prevalence of osteoporotic-related fractures. The primary goal of this study was to analyse the association of patient characteristics with the cortical bone thickness of the distal tibia (CBTT) in trimalleolar ankle fractures. Methods: A total of 193 patients with a trimalleolar ankle fracture treated between 2011 and 2020 were included. Patient registries were reviewed regarding demographics, mechanism, and type of injury. The CBTT was assessed in radiographs and CT images. The FRAX score was calculated to estimate the probability for an osteoporotic fracture. A multivariable regression model was calculated to identify independent variables affecting the cortical bone thickness of the distal tibia. Results: Patients older than 55 years were 4.22 (95% CI: 2.12; 8.38) times more likely to be female. In the multivariable regression analysis, female sex (β −0.508, 95% CI: −0.739; −0.278, p < 0.001) and a higher age (β −0.009, 95% CI: −0.149; −0.003, p = 0.002) were independent variables associated with a lower CBTT. Patients with a CBTT < 3.5 mm had a higher 10-year probability for a major osteoporotic fracture (12% vs. 7.75%; p = 0.001). Conclusions: The assessment of the peripheral bone quality in routine computed tomography demonstrated that higher age and female sex are significantly associated with reduced cortical bone thickness of the distal tibia. Patients with a lower CBTT showed a higher probability for a subsequent osteoporotic fracture. In female patients with reduced distal tibial bone quality and associated risk factors, an osteoporosis assessment should be evaluated. [ABSTRACT FROM AUTHOR]

Purpose: Pancreatic ductal adenocarcinoma (PDAC) is a molecularly heterogeneous tumor entity with no clinically established imaging biomarkers. We hypothesize that tumor morphology and physiology, including vascularity and perfusion, show variations that can be detected by differences in contrast agent (CA) accumulation measured non-invasively. This work seeks to establish imaging biomarkers for tumor stratification and therapy response monitoring in PDAC, based on this hypothesis. Methods and materials: Regional CA accumulation in PDAC was correlated with tumor vascularization, stroma content, and tumor cellularity in murine and human subjects. Changes in CA distribution in response to gemcitabine (GEM) were monitored longitudinally with computed tomography (CT) Hounsfield Units ratio (HUr) of tumor to the aorta or with magnetic resonance imaging (MRI) ΔR1 area under the curve at 60 s tumor-to-muscle ratio (AUC60r). Tissue analyses were performed on co-registered samples, including endothelial cell proliferation and cisplatin tissue deposition as a surrogate of chemotherapy delivery. Results: Tumor cell poor, stroma-rich regions exhibited high CA accumulation both in human (meanHUr 0.64 vs. 0.34, p < 0.001) and mouse PDAC (meanAUC60r 2.0 vs. 1.1, p < 0.001). Compared to the baseline, in vivo CA accumulation decreased specifically in response to GEM treatment in a subset of human (HUr −18%) and mouse (AUC60r −36%) tumors. Ex vivo analyses of mPDAC showed reduced cisplatin delivery (GEM: 0.92 ± 0.5 mg/g, vs. vehicle: 3.1 ± 1.5 mg/g, p = 0.004) and diminished endothelial cell proliferation (GEM: 22.3% vs. vehicle: 30.9%, p = 0.002) upon GEM administration. Conclusion: In PDAC, CA accumulation, which is related to tumor vascularization and perfusion, inversely correlates with tumor cellularity. The standard of care GEM treatment results in decreased CA accumulation, which impedes drug delivery. Further investigation is warranted into potentially detrimental effects of GEM in combinatorial therapy regimens. [ABSTRACT FROM AUTHOR]

Simple Summary: Since prostate MRI is increasingly applied and yet limited by long acquisition times, we prospectively investigated the performance of a novel reconstruction algorithm combining compressed sensing, parallel imaging and deep learning (C-SENSE AI) in patients with histologically proven prostate cancer. Highly accelerated T2w images were compared to clinical standard-of-reference T2w images. C-SENSE AI enabled a 58% acceleration in T2w imaging of the prostate while obtaining significantly better image quality and tumor detection. C-SENSE AI seems particularly interesting in view of the need for accelerated prostate MRI (e.g., in screening protocols) with preserved high image quality. Background: To assess the performance of prospectively accelerated and deep learning (DL) reconstructed T2-weighted (T2w) imaging in volunteers and patients with histologically proven prostate cancer (PCa). Methods: Prospectively undersampled T2w datasets were acquired with acceleration factors of 1.7 (reference), 3.4 and 4.8 in 10 healthy volunteers and 23 patients with histologically proven PCa. Image reconstructions using compressed SENSE (C-SENSE) and a combination of C-SENSE and DL-based artificial intelligence (C-SENSE AI) were analyzed. Qualitative image comparison was performed using a 6-point Likert scale (overall image quality, noise, motion artifacts, lesion detection, diagnostic certainty); the T2 and PI-RADS scores were compared between the two reconstructions. Additionally, quantitative image parameters were assessed (apparent SNR, apparent CNR, lesion size, line profiles). Results: All C-SENSE AI-reconstructed images received a significantly higher qualitative rating compared to the C-SENSE standard images. Analysis of the quantitative parameters supported this finding, with significantly higher aSNR and aCNR. The line profiles demonstrated a significantly steeper signal change at the border of the prostatic lesion and the adjacent normal tissue in the C-SENSE AI-reconstructed images, whereas the T2 and PI-RADS scores as well as the lesion size did not differ. Conclusion: In this prospective study, we demonstrated the clinical feasibility of a novel C-SENSE AI reconstruction enabling a 58% acceleration in T2w imaging of the prostate while obtaining significantly better image quality. [ABSTRACT FROM AUTHOR]

Purpose: Different classification systems have been developed for ankle fractures. In recent years, the posterior malleolus has gained in importance and led to computed tomography (CT)-based classification systems. The aim of the study was to analyse their reliability, fracture patterns and influence on treatment strategy. Methods: Patients with a trimalleolar ankle fracture treated between 2011 and 2020 with preoperative radiographs and CT images were included. The blinded images were independently classified by three reviewers according to the AO/OTA, Herscovici, Bartoníček, Mason and Haraguchi classifications. The interobserver reliability was calculated by Fleiss' kappa (κ). CT images were analysed to determine the dimensions of the posterior malleolus fragments. Patient registries were reviewed regarding the treatment data. Results: A total of 193 patients were included. The AO/OTA classification showed almost perfect inter- and intraobserver reliability (Fleiss' κ = 0.86, 95% CI 0.82–0.90). Regarding the posterior malleolus, the Bartoníček classification demonstrated the highest reliability (Fleiss' κ = 0.78, 95% CI 0.73–0.83). The Herscovici classification only reached moderate reliability for medial malleolus fractures (Fleiss' κ = 0.59, 95% CI 0.54–0.65). There was a trend towards direct fixation of the posterior malleolus in the last 3 years of the observation period (OR: 2.49, 95% CI 1.03–5.99). Conclusion: In trimalleolar ankle fractures, the AO/OTA classification is a reliable system to characterize the type of fracture, but it fails to provide solid information about the posterior malleolus. Nowadays, treatment recommendations for trimalleolar ankle fractures focus on the configuration of the posterior malleolus; therefore, the results of this study advocate the use of the Bartoníček classification as a reliable tool to guide treatment. [ABSTRACT FROM AUTHOR]

Introduction: Exposure of the posterior skull base and the cerebellopontine angle is challenging due to important neurovascular structures. The retrosigmoid approach (RSA) has become the standard method used in surgery. We report our experiences with RSAs regarding technical obstacles, complications, and approach-related outcomes. Materials and Methods: We performed a retrospective chart review at a tertiary neurosurgical center between January 2007 and September 2020. We included all patients undergoing surgery for oncologic lesions through RSAs, concentrating on surgical technique, postoperative outcome, and complications. Results: A total of 449 RSAs were included. The median age at the time of surgery was 58 years; 168 (37.4%) were male and 281 (62.6%) were female. The median approach surface was 7.8 cm2. The median tumor volume was 5.9 cm3. The median Clavien-Dindo grade was 2, the total complication rate was 28.7%, and gross total resection (GTR) was 78.8%. Findings revealed that tumor volume had no significant impact on postoperative complications in general (p = 0.086) but had a significant impact on postoperative hemorrhage (p = 0.037) and hydrocephalus (p = 0.019). Tumor volume was significant for several preoperative symptoms (p < 0.001). The extent of the approach had no significant impact on complications in general (p = 0.120) but was significant regarding postoperative cerebrospinal fluid (CSF) leaks (p = 0.008). Craniotomy size was not significant regarding GTR (p = 0.178); GTR rate just missed significant correlation with tumor volume (p = 0.056). However, in the case of vestibular schwannomas, the size of craniotomy was important for GTR (p = 0.041). Conclusion: Tumor volume has an important impact on preoperative symptoms as well as on postoperative complications. Although the extent of the craniotomy barely missed significance regarding GTR, a correlation can be assumed. Thus, the extent of craniotomy should be taken into presurgical consideration, especially in the case of postoperative CSF leaks. Regarding vestibular schwannomas, craniotomy size plays an important role in achieving satisfactory oncological outcomes. Different approaches should be selected where necessary regarding superior resection rates. [ABSTRACT FROM AUTHOR]

Despite the advance and success of precision oncology in gastrointestinal cancers, the frequency of molecular‐informed therapy decisions in pancreatic ductal adenocarcinoma (PDAC) is currently neglectable. We present a longitudinal precision oncology platform based on functional model systems, including patient‐derived organoids, to identify chemotherapy‐induced vulnerabilities. We demonstrate that treatment‐induced tumor cell plasticity in vivo distinctly changes responsiveness to targeted therapies, without the presence of a selectable genetic marker, indicating that tumor cell plasticity can be functionalized. By adding a mechanistic layer to precision oncology, adaptive processes of tumors under therapy can be exploited, particularly in highly plastic tumors, such as pancreatic cancer. Synopsis: Therapy resistance remains a major challenge in pancreatic cancer. This study used patient‐derived organoids (PDOs) and cell lines (PDCL) to investigate response to standard‐of‐care chemotherapy administered in humans. We show that chemotherapy‐induced adaption exposes novel therapeutic vulnerabilities accompanied by cellular re‐differentiation. Longitudinal generation of pancreatic cancer PDOs allows to study treatment‐imposed plasticity.Treatment‐induced non‐genetic mechanism impact on cellular plasticity and therapeutic vulnerabilities.Differentiation within the EMT spectrum of tumor cells upon chemotherapy is not restricted to acquisition of mesenchymal phenotypes but allows epithelial re‐differentiation. [ABSTRACT FROM AUTHOR]

Purpose: In this prospective exploratory study, we evaluated the feasibility of [18F]fluorodeoxyglucose ([18F]FDG) PET/MRI-based chemotherapy response prediction in pancreatic ductal adenocarcinoma at two weeks upon therapy onset. Material and methods: In a mixed cohort, seventeen patients treated with chemotherapy in neoadjuvant or palliative intent were enrolled. All patients were imaged by [18F]FDG PET/MRI before and two weeks after onset of chemotherapy. Response per RECIST1.1 was then assessed at 3 months [18F]FDG PET/MRI-derived parameters (MTV50%, TLG50%, MTV2.5, TLG2.5, SUVmax, SUVpeak, ADCmax, ADCmean and ADCmin) were assessed, using multiple t-test, Man–Whitney-U test and Fisher's exact test for binary features. Results: At 72 ± 43 days, twelve patients were classified as responders and five patients as non-responders. An increase in ∆MTV50% and ∆ADC (≥ 20% and 15%, respectively) and a decrease in ∆TLG50% (≤ 20%) at 2 weeks after chemotherapy onset enabled prediction of responders and non-responders, respectively. Parameter combinations (∆TLG50% and ∆ADCmax or ∆MTV50% and ∆ADCmax) further improved discrimination. Conclusion: Multiparametric [18F]FDG PET/MRI-derived parameters, in particular indicators of a change in tumor glycolysis and cellularity, may enable very early chemotherapy response prediction. Further prospective studies in larger patient cohorts are recommended to their clinical impact. [ABSTRACT FROM AUTHOR]

We show that the Mordukhovich-stationarity system associated with a mathematical program with complementarity constraints (MPCC) can be equivalently written as a system of discontinuous equations which can be tackled with a semismooth Newton method. It will be demonstrated that the resulting algorithm can be interpreted as an active set strategy for MPCCs. Local fast convergence of the method is guaranteed under validity of an MPCC-tailored version of LICQ and a suitable strong second-order condition. In case of linear-quadratic MPCCs, the LICQ-type constraint qualification can be replaced by a weaker condition which depends on the underlying multipliers. We discuss a suitable globalization strategy for our method. Some numerical results are presented in order to illustrate our theoretical findings. [ABSTRACT FROM AUTHOR]

In this paper, we show how a special class of inverse optimal control problems of elliptic partial differential equations can be solved globally. Using the optimal value function of the underlying parametric optimal control problem, we transfer the overall hierarchical optimization problem into a nonconvex single-level one. Unfortunately, standard regularity conditions like Robinson's CQ are violated at all the feasible points of this surrogate problem. It is, however, shown that locally optimal solutions of the problem solve a Clarke-stationarity-type system. Moreover, we relax the feasible set of the surrogate problem iteratively by approximating the lower level optimal value function from above by piecewise affine functions. This allows us to compute globally optimal solutions of the original inverse optimal control problem. The global convergence of the resulting algorithm is shown theoretically and illustrated by means of a numerical example. [ABSTRACT FROM AUTHOR]

We consider bilevel optimization problems which can be interpreted as inverse optimal control problems. The lower-level problem is an optimal control problem with a parametrized objective function. The upper-level problem is used to identify the parameters of the lower-level problem. Our main focus is the derivation of first-order necessary optimality conditions. We prove C-stationarity of local solutions of the inverse optimal control problem and give a counterexample to show that strong stationarity might be violated at a local minimizer. [ABSTRACT FROM AUTHOR]

We investigate the limiting normal cone of the complementarity set associated with non-negative functions in the Sobolev space . By using results from homogenization theory, we provide lower estimates for this limiting normal cone. These estimates are unpleasantly large. [ABSTRACT FROM AUTHOR]

Legendre forms are used in the literature for second-order sufficient optimality conditions of optimization problems in (reflexive) Banach spaces. We show that if a Legendre form exists on a reflexive Banach space, then this space is already isomorphic to a Hilbert space. [ABSTRACT FROM AUTHOR]

Abstract: We consider stationarity systems for the optimal control of the obstacle problem. The focus is on the comparison of several different systems which are provided in the literature. We obtain some novel results concerning the relations between these stationarity concepts. [ABSTRACT FROM AUTHOR]

Abstract: We consider stationarity systems for the optimal control of the obstacle problem. The focus is on the comparison of several different systems which are provided in the literature. We obtain some novel results concerning the relations between these stationarity concepts. [ABSTRACT FROM AUTHOR]

Objectives: To evaluate the long-term disease-free and overall survival of patients with sentinel lymph node (SLN) micrometastases, in whom a completion axillary lymph node dissection (ALND) was systematically omitted. Background: The use of step sectioning and immunohistochemistry for SLN analysis results in a more accurate histopathologic examination and a higher detection rate of micrometastases. However, the clinical relevance and therapeutic implications of SLN micrometastases remain a matter of debate. Methods: In this prospective study, 236 SLN biopsies were performed in 234 consecutive early-stage breast cancer patients (T1, T2 ≤ 3 cm, cN0 M0) between 1998 and 2002. The SLN were examined by step sectioning and stained with hematoxylin and eosin and immunohistochemistry. None of the patients with negative SLN or SLN micrometastases (International Union Against Cancer classification, >0.2 to ≤ 2 mm) underwent a completion ALND or radiation to the axilla. Long-term overall and disease-free survivals were compared between patients with negative SLN and those with SLN micrometastases by log rank tests. Results: The SLN was negative in 55% of patients (123 of 224). SLN micrometastases were detected in 27 patients (27 of 224, 12%). After a median followup of 77 months (range, 24-106 months), neither locoregional recurrences nor distant metastases occurred in any of the 27 patients with SLN micrometastases. There were no statistically significant differences for overall ( P = 0.656), locoregional ( P = 0.174), and axillary and distant disease-free survival ( P = 0.15) between patients with negative SLN and SLN micrometastases. Conclusions: This analysis of unselected patients provides evidence that a completion level I and II ALND may be safely omitted in early-stage breast cancer patients with SLN micrometastases. [ABSTRACT FROM AUTHOR]

Advanced-stage melanoma here dismal prognosis, and novel therapeutic approaches are urgently required. The possibility of taking advantage of the immune response of patients for its treatment has been an appealing concept for almost a century. Only during the last decade, however, has the molecular identification of tumor-associated antigens (TAAs) offered the possibility of vaccinating patients l e.g., active induction of TAA-specific immune responses). Active antigen-specific immunotherapy (AASIT) is currently being investigated in a number of clinical centers as a treatment option for advanced-stage melanoma. A large number of melanoma TAAs have been molecularly characterized and are being used in vaccination trials in various molecular forms and according to various immunization protocols. Here we provide a short overview on melanoma TAAs, the technologies currently in use to induce specific cytotoxic T-lymphocyte (CTL) responses in vivo, and their monitoring. We also propose a tentative AASIT agenda for the next few years, aiming at improving the capacity to induce and monitor TAA-specific immune responses and to verify their clinical effectiveness. [ABSTRACT FROM AUTHOR]

Recent studies have shown that the sentinel lymph node (SLN) procedure might improve staging in colon cancer. However, low SLN identification and high false negative rates have also been reported. In a two-institution study, the SLN procedure with isosulfan blue 1% was performed according to a standardized protocol in 31 patients with open resections for colon cancer. Data were collected prospectively. The database was analyzed retrospectively to determine factors contributing to a low identification rate. The SLN identification rate was 87% and the false negative rate was 50%. Successful SLN identification was significantly associated with application of higher volumes of dye relative to the tumor diameter (p = 0.04) and more frequent tumor localization in the sigmoid colon (p = 0.04) as compared to missing SLN identification. The tumor diameter was not significantly different in the two groups. Sentinel lymph node identification in colon cancer depends on the amount of dye injected relative to the tumor size. Application of only 1 ml of dye—the amount generally recommended in the literature—is not sufficient in large tumors. [ABSTRACT FROM AUTHOR]

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Objective: To assess the potential of advanced breast biopsy instrumentation (ABBI) to clarify the diagnosis of impalpable mammographic lesions and to remove the entire malignant lesions with clear margins. Design: Prospective assessment in a consecutive series of patients. Setting: University hospital, Basel, Switzerland. Subjects: 139 patients presenting with144 impalpable microcalcifications or solid nodular densities evident on screening and follow-up mammograms that were suspicious of malignancy. Main outcome measures: Feasibility, sensitivity, efficiency in obtaining definitive diagnoses in an outpatient clinic under local anaesthesia, feasibility of complete removal of a primary malignancy, and intervention-related morbidity. Results: The ABBI procedure was successful in 135/144 (94%); an accurate diagnosis was made in 129/130 patients followed up (99%), sensitivity for malignant lesions was 31/32 (97%) and there were 2 complications (2%). Margins of the biopsy cylinder contained a malignant lesion in 26/31 (84%). Conclusions: Excisional biopsy using the ABBI system is a reliable diagnostic tool with a low morbidity. As in other published series margins were often not clear of tumour and therefore the therapeutic use of the ABBI procedure is limited. [ABSTRACT FROM AUTHOR]

Hypothesis: Telemedicine for real-time transmission of clinical documents and interactive remote telediagnosis allows accurate clinical application in surgery. Design: Prospective cohort study in which 2 hospitals, 120 miles apart, were connected via integrated services digital network (ISDN) teleconferencing units, and each evaluated clinical cases in real time. Setting: A tertiary care university hospital and primary care county hospital. Participants: Between May 1, 1998, and June 30, 1998, 112 patients undergoing digestive or endocrine surgery were evaluated by teletransmission (study group) and direct vision (control group). Diagnosis had to be known by the viewer, and either conventional magnetic resonance imaging or computed tomographic scans were available. Main Outcome Measures: Picture quality, organ structure, and pathologic finding viewed on telemedicine documents were evaluated by radiologists and surgeons blind to diagnosis. Accuracy of remote 128–kilobit (kb)/s transmission-rate diagnoses and results were compared with those obtained directly. Results: Picture quality was "good" or "excellent" in 92.9% of transmitted documents and 95.5% of live images (P>.4). The target organ was always recognized, structure and pathologic finding were analyzable in 98.2% of transmitted documents and 99.1% of live documents, and fine structures were assessable in 89.3% of transmitted pictures and 95.5% of live pictures (P>.05). Diagnosis was made in 84.8% of transmitted cases and 93.8% of live cases (P=.02). Conclusions: Low bandwidth (128 kb/s) telemedicine application in surgery is reliable in evaluating remote cases. Loss of image quality through teletransmission occurred in 2.7% of cases, and diagnosis was not possible in 15.2% of transmitted vs 6.2% of live cases, suggesting factors other than technical quality (choice of radiological studies, additional clinical information required, etc). This underscores the importance of real-time interactive... [ABSTRACT FROM AUTHOR]

A questionnaire was sent to the chief surgeons at 141 Swiss hospitals to evaluate their knowledge and acceptance of telemedicine in surgery. The response rate was 69%. Ninety-three per cent of all surgical departments used computer technology, 85% regularly used the Web and 88% had an internal hospital network. ISDN lines were used in 58% of the participants' hospitals. While 35% of respondents had participated at least once in networking, only 8% regularly used telemedicine. The opinion was that access to therapeutic advice (87%) was a better use of telemedicine than was obtaining a primary diagnosis (24%), although the majority accepted the principle of making (91%) and receiving (94%) a remote diagnosis. The survey suggested that surgeons are interested in telemedicine and open to its development, although their experience and knowledge are limited. Therefore, telemedicine in surgery may be advanced by creating surgical networks for teleconsultation and tele-education. [ABSTRACT FROM AUTHOR]

Hypothesis: Magnetic resonance cholangiography (MRC) offers the potential for accurate, noninvasive detection of common bile duct stones (CBDSs) before cholecystectomy, and for a consequent reduction in the incidence of preoperative negative diagnoses associated with endoscopic retrograde cholangiography (ERC). Design: Prospective cohort study: MRC results were correlated with ERC (high-risk patients) or intraoperative cholangiography (moderate-risk patients). Setting: A university hospital providing primary, secondary, and tertiary care. Patients: Seventy patients with suspected CBDSs scheduled to undergo elective cholecystectomy between April 15, 1997, and September 30, 1998. Forty patients were considered at high risk and 30 at moderate risk for CBDSs, according to results of liver function tests and sonograms of the upper abdomen. Main Outcome Measures: Confirmation or exclusion of CBDSs by MRC was assessed by a panel of radiologists who were unaware of the ERC results. Results of ERC and intraoperative cholangiography were analyzed by the investigating gastroenterologists or surgeon. Results: Results of MRC were positive for CBDSs in 21 (52%) of 40 high-risk patients, a finding confirmed by preoperative ERC in 19 (90%) of 21 patients. Results of MRC were positive for CBDSs in 6 (20%) of 30 moderate-risk patients, all of which were confirmed by intraoperative cholangiography. Finally, CBDSs were present in 19 (48%) of 40 high-risk patients and 6 (20%) of 30 moderate-risk patients (P = .02). Overall sensitivity and specificity of MRC were 100% and 95.6%, respectively; the positive and negative predictive values were 92.6% and 100%, respectively. Conclusions: Magnetic resonance cholangiography is a reliable, noninvasive method for the detection or exclusion of CBDSs, and seems to reduce the frequency of negative diagnoses associated with ERC. Magnetic resonance cholangiography revealed no CBDSs in 19 (48%) of 40 patients at high risk for CBDSs. Thus, MRC... [ABSTRACT FROM AUTHOR]

Focuses on the history of surgery in Switzerland. Development of the Swiss Society of Surgery; Rules governing postgraduate training; Function of surgery in Switzerland; Challenges that should be faced by modern Swiss surgery.

Mainly because of the loss of reservoir function, loss of sphincter function, and exclusion of the duodenal route, patients who undergo gastrectomy suffer from many adverse effects postoperatively. The ileocecal interpositional graft is an attractive method to use as a gastric substitute after gastrectomy and distal esophagectomy. A pedunculated ileocecal graft is placed between the esophagus and the duodenum. The cecum acts as a reservoir while the ileocecal valve protects against enteroesophageal reflux. The duodenal passage is also preserved. Fourteen patients underwent this operation. The technique-related morbidity was low and the quality of life was good. During a mean follow-up of 6 months, no evidence of severe dumping syndrome or reflux esophagitis was observed. Further prospective randomized studies are warranted to compare this technique with the standard methods of gastric reconstruction. [ABSTRACT FROM AUTHOR]

Copyright of World Journal of Surgery is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of World Journal of Surgery is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of World Journal of Surgery is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of World Journal of Surgery is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of World Journal of Surgery is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Intestinal nonrotation has been recognized as a cause of obstruction in neonates and children and may be complicated by volvulus and intestinal necrosis. It is very rarely seen in the adult and may present acutely as a bowel obstruction and intestinal ischemia associated with midgut or ileocecal volvulus, or chronically as vague intermittent abdominal pain. The purpose of this communication is to reveal the pathogenesis and the surgical significance of intestinal nonrotation in adults and to review the English and German language literature since 1923 to establish the optimal therapeutic management. Between 1983 and 1992, we have managed and observed prospectively 10 adults with intestinal nonrotation. In four patients the nonrotation has been detected at emergency laparotomy owing to midgut or ileocecal volvulus. Four patients suffered from chronic symptoms of intermittent volvulus or small bowel obstruction and in two patients the nonrotation has been noted as an incidental finding at laparotomy for another condition. A survey of the literature from 1923 to 1992 revealed 40 adults with symptomatic intestinal nonrotation to which we contribute nine patients. We establish that in the acute symptomatic pattern, only emergency laparotomy can provide the correct diagnosis and decrease the risk of bowel disturbance. In the chronic situation, barium studies of the upper and lower gastrointestinal tract reveal varying degrees of midgut malrotation and confirm the nonrotation in each case. Also, in these forms the explorative laparotomy with a consequent staging of the abdominal situs is to be recommended. All reported cases at our institutions are without complaints after surgery. Adult patients with intestinal nonrotation and acute or chronic obstructive symptoms or those detected incidentally at laparotomy for other conditions should undergo a Ladd procedure because of the risk of midgut volvulus. In this operation, the nonrotation is left in place and the ascending colon is sutured at the colon descendens and sigmoideum. After this procedure the mesenteric pedicle is fixed and the risk of midgut torsion remains minimal. [ABSTRACT FROM AUTHOR]

Examines the role of spleen in immune response to polyvalent pneumococcal vaccine. Use of antibiotics for the treatment of pneumococcal infections; Synthesis of immunoglobulin G antipneumococcal capsular polysaccharides; Disappearance of B cells population after 21 days of immunization.