3D Ultrasound and MRI in Assessing Resection Margins during Tongue Cancer Surgery: A Research Protocol for a Clinical Diagnostic Accuracy Study.

Surgery is the primary treatment for tongue cancer. The goal is a complete resection of the tumor with an adequate margin of healthy tissue around the tumor.Inadequate margins lead to a high risk of local cancer recurrence and the need for adjuvant therapies. Ex vivo imaging of the resected surgical specimen has been suggested for margin assessment and improved surgical results. Therefore, we have developed a novel three-dimensional (3D) ultrasound imaging technique to improve the assessment of resection margins during surgery. In this research protocol, we describe a study comparing the accuracy of 3D ultrasound, magnetic resonance imaging (MRI), and clinical examination of the surgical specimen to assess the resection margins during cancer surgery. Tumor segmentation and margin measurement will be performed using 3D ultrasound and MRI of the ex vivo specimen. We will determine the accuracy of each method by comparing the margin measurements and the proportion of correctly classified margins (positive, close, and free) obtained by each technique with respect to the gold standard histopathology.

Automatic and unbiased assessment of competence in colonoscopy: exploring validity of the Colonoscopy Progression Score (CoPS).

Background and aims: Colonoscopy is a difficult procedure to master. Increasing demands for colonoscopy, due to screening and surveillance programs, have highlighted the need for competent performers. Valid methods for assessing technical skills are pivotal for training and assessment. This study is the first clinical descriptive report of a novel colonoscopy assessment tool based on Magnetic Endoscopic Imaging (MEI) data and the aim was to gather validity evidence based on the data collected using the "Colonoscopy Progression Score" (CoPS). Methods: We recorded 137 colonoscopy procedures performed by 31 endoscopists at three university hospitals. The participants performed more than two procedures each (range 2 - 12) and had an experience of 0 - 10 000 colonoscopies. The CoPS was calculated for each recording and validity was explored using a widely accepted contemporary framework. The following sources of validity evidence were explored: response process (data collection), internal structure (reliability), relationship to other variables (i. e. operator experience), and consequences of testing (pass/fail). Results: Identical set-ups at all three locations ensured uniform data collection. The Generalizability coefficient (G-coefficient) was 0.80, and a Decision-study (D-study) revealed that four recordings were sufficient to ensure a G-coefficient above 0.80. We showed a positive correlation between CoPS and experience with Pearson's r of 0.61 (P < 0.001). A pass/fail standard of 107 points was established using the contrasting group method to explore the consequences of testing. Conclusion: This study provides evidence supporting the validity of the CoPS for use in assessing technical colonoscopy performance in the clinical setting. STUDY REGISTRATION: NCT01997177.

Laser Speckle Contrast Imaging for Monitoring Changes in Microvascular Blood Flow.

BACKGROUND/AIMS: Microvascular blood flow is essential for healing and predicts surgical outcome. The aim of the current study was to investigate the relation between fluxes measured with the laser speckle contrast imaging (LSCI) technique and changes in absolute blood flow. In addition, we studied the reproducibility of the LSCI technique when assessing the intra-abdominal microcirculation of the pig. METHODS: During trial 1, a fish gill arch was mechanically perfused with heparinized fish blood under controlled stepwise-altered flow rates alongside mechanically induced movement artefacts. The microcirculation of the fish gill was simultaneously assessed with the LSCI technique. In trial 2, microcirculation was measured in the stomach, liver, and small intestine of 10 pigs by two observers. RESULTS: A linear correlation was observed between flux and volumetric flow. During conditions of no volumetric flow, the high recording speed with the LSCI technique registered the movement artefacts as flow signals. The LSCI measurements showed good correlation and agreement between the two observers when assessing microcirculation in the stomach, liver, and small intestine (r2 = 0.857, 0.956, and 0.946; coefficients of variation = 6.0, 3.2, and 6.4%, respectively). CONCLUSION: Due to the non-contact and real-time assessment over large areas, LSCI is a promising technique for the intraoperative assessment of intra-abdominal microcirculation. A linear correlation between flux and volumetric flow was found, in accordance with previous experimental studies. However, movement artefacts affect flux measurements, and the choice of the sampling speed must be made with care, depending on the given setting.

Assessment of competence in simulated flexible bronchoscopy using motion analysis.

BACKGROUND: Flexible bronchoscopy should be performed with a correct posture and a straight scope to optimize bronchoscopy performance and at the same time minimize the risk of work-related injuries and endoscope damage. OBJECTIVES: We aimed to test whether an automatic motion analysis system could be used to explore if there is a correlation in scope movements and the operator's level of experience. Our hypothesis was that experienced bronchoscopists move less and keep the flexible scope straighter than less-experienced bronchoscopists while performing procedures. METHODS: Eleven novices, 9 intermediates and 9 experienced bronchoscopy operators performed 3 procedures each on a bronchoscopy simulator. The Microsoft Kinect system was used to automatically measure the total deviation of the scope from a perfectly straight, vertical line. RESULTS: The low-cost motion analysis system could measure the accumulated deviation of the scope precisely during the procedure. The deviations were greatest for the novices and smallest for the most experienced operators for all 3 procedures (p = 0.01, p = 0.01 and p = 0.04, respectively). The total deviation from the straight scope correlated negatively with the performance on the simulator (virtual-reality simulator score; p < 0.001). CONCLUSION: The motion analysis system could discriminate between different levels of experience. Automatic feedback on correct movements during self-directed training on simulators might help new bronchoscopists learn how to handle the bronchoscope like an expert.