Lymph node metastasis of squamous cell carcinoma from an unknown primary in the upper and middle neck: impact of 18F-fluorodeoxyglucose positron emission tomography/computed tomography

Purpose: The purpose of this study was to assess the potential of F-18-fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) imaging for detection of the primary tumor and its impact on treatment planning in patients presenting with cancer of unknown primary and squamous cell carcinoma (SCC)-positive cervical lymph nodes of the upper and middle neck. Methods: The study population consisted of 18 consecutive patients with biopsy-proven SCC involving lymph nodes of the upper and middle neck region and negative conventional diagnostic procedures with regard to the location of the primary. All patients underwent FDG-PET/CT according to a standard procedure in search for the primary, unidentified tumor. Results: In none of the patients FDG-PET/CT was able to indicate a primary tumor localization. Although FDGPET/CT did identify all sites of known lymph node involvement, neither additional sites of lymph node involvement nor sites of distant metastases were identified. Accordingly, FDG-PET/CT did not impact patient treatment planning. Conclusions: In this series, including patients suffering from lymph node metastases by an SCC of unknown primary in the upper and middle neck, FDG-PET/CT was unable to identify a primary tumor. In addition, FDGPET/CT did not modify the treatment planning in any of the patients studied

Fluid dynamic treatment of thixotropic debris flows and avalanches

Some forms of mud flows and debris flows exhibit a non-Newtonian thixotropic behaviour, and this study describes a basic study of dam break wave with thixotropic fluid. Theoretical considerations were developed based upon a kinematic wave approximation of the Saint-Venant equations down a prismatic sloping channel and combined with the thixotropic rheological model of Coussot et al. (2002). The analytical solution of basic flow motion and rheology equations predicts three basic flow regimes depending upon the fluid properties and flow conditions, including the initial degree of jamming of the fluid. The present work is the first theoretical analysis combining successfully the basic principles of unsteady flow motion with a thixotropic fluid model, which was verified with systematic laboratory experiments

Development and pre-validation of a high sensitive method for the determination of levonorgestrel in human plasma by SPE/LC/MS-MS

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