Broadband hyperspectral imaging for breast tumor detection using spectral and spatial information

Complete tumor removal during breast-conserving surgery remains challenging due to the lack of optimal intraoperative margin assessment techniques. Here, we use hyperspectral imaging for tumor detection in fresh breast tissue. We evaluated different wavelength ranges and two classification algorithms; a pixel-wise classification algorithm and a convolutional neural network that combines spectral and spatial information. The highest classification performance was obtained using the full wavelength range (450-1650nm). Adding spatial information mainly improved the differentiation of tissue classes within the malignant and healthy classes. High sensitivity and specificity were accomplished, which offers potential for hyperspectral imaging as a margin assessment technique to improve surgical outcome. (C) 2019 Optical Society of America under the terms of the OSA Open Access Publishing Agreemen

Scanning tunnelling miscroscopy/spectroscopy and X-ray absorption spectroscopy studies of Co adatoms and anoislands on highly oriented pyrolytic graphite

In this paper, the scanning tunneling microscopy, scanning tunneling spectroscopy and X-ray absorption spectroscopy of cobalt adatoms and nanoislands were studied on a highly oriented pyrolytic graphite. Local electronic structure were observed by STS.\ud \u

Method for coregistration of optical measurements of breast tissue with histopathology : the importance of accounting for tissue deformations

For the validation of optical diagnostic technologies, experimental results need to be benchmarked against the gold standard. Currently, the gold standard for tissue characterization is assessment of hematoxylin and eosin (H&E)-stained sections by a pathologist. When processing tissue into H&E sections, the shape of the tissue deforms with respect to the initial shape when it was optically measured. We demonstrate the importance of accounting for these tissue deformations when correlating optical measurement with routinely acquired histopathology. We propose a method to register the tissue in the H&E sections to the optical measurements, which corrects for these tissue deformations. We compare the registered H&E sections to H&E sections that were registered with an algorithm that does not account for tissue deformations by evaluating both the shape and the composition of the tissue and using microcomputer tomography data as an independent measure. The proposed method, which did account for tissue deformations, was more accurate than the method that did not account for tissue deformations. These results emphasize the need for a registration method that accounts for tissue deformations, such as the method presented in this study, which can aid in validating optical techniques for clinical use. (C) The Authors. Published by SPIE under a Creative Commons Attribution 4.0 Unported License

Somatostatin analogues for receptor targeted photodynamic therapy

Photodynamic therapy (PDT) is an established treatment modality, used mainly for anticancer therapy that relies on the interaction of photosensitizer, light and oxygen. For the treatment of pathologies in certain anatomical sites, improved targeting of the photosensitizer is necessary to prevent damage to healthy tissue. We report on a novel dual approach of targeted PDT (vascular and cellular targeting) utilizing the expression of neuropeptide somatostatin receptor (sst2) on tumor and neovascular-endothelial cells. We synthesized two conjugates containing the somatostatin analogue [Tyr3]-octreotate and Chlorin e6 (Ce6): Ce6-K3-[Tyr3]-octreotate (1) and Ce6-[Tyr3]-octreotate-K3-[Tyr3]-octreotate (2). Investigation of the uptake and photodynamic activity of conjugates in-vitro in human erythroleukemic K562 cells showed that conjugation of [Tyr3]-octreotate with Ce6 in conjugate 1 enhances uptake (by a factor 2) in cells over-expressing sst2 compared to wild-type cells. Co-treatment with excess free Octreotide abrogated the phototoxicity of conjugate 1 indicative of a specific sst2-mediated effect. In contrast conjugate 2 showed no receptor-mediated effect due to its high hydrophobicity. When compared with un-conjugated Ce6, the PDT activity of conjugate 1 was lower. However, it showed higher photostability which may compensate for its lower phototoxicity. Intra-vital fluorescence pharmacokinetic studies of conjugate 1 in rat skin-fold observation chambers transplanted with sst2+ AR42J acinar pancreas tumors showed significantly different uptake profiles compared to free Ce6. Co-treatment with free Octreotide significantly reduced conjugate uptake in tumor tissue (by a factor 4) as well as in the chamber neo-vasculature. These results show that conjugate 1 might have potential as an in-vivo sst2 targeting photosensitizer conjugate

Margin assessment during breast conserving surgery using diffuse reflectance spectroscopy

Significance: During breast-conserving surgeries, it is essential to evaluate the resection margins (edges of breast specimen) to determine whether the tumor has been removed completely. In current surgical practice, there are no methods available to aid in accurate real-time margin evaluation.Aim: In this study, we investigated the diagnostic accuracy of diffuse reflectance spectroscopy (DRS) combined with tissue classification models in discriminating tumorous tissue from healthy tissue up to 2 mm in depth on the actual resection margin of in vivo breast tissue.Approach: We collected an extensive dataset of DRS measurements on ex vivo breast tissue and in vivo breast tissue, which we used to develop different classification models for tissue classification. Next, these models were used in vivo to evaluate the performance of DRS for tissue discrimination during breast conserving surgery. We investigated which training strategy yielded optimum results for the classification model with the highest performance.Results: We achieved a Matthews correlation coefficient of 0.76, a sensitivity of 96.7% (95% CI 95.6% to 98.2%), a specificity of 90.6% (95% CI 86.3% to 97.9%) and an area under the curve of 0.98 by training the optimum model on a combination of ex vivo and in vivo DRS data.Conclusions: DRS allows real-time margin assessment with a high sensitivity and specificity during breast-conserving surgeries.</p

Long-term restoration of bowel continuity after rectal cancer resection and the influence of surgical technique:A nationwide cross-sectional study

Aim: Literature on nationwide long-term permanent stoma rates after rectal cancer resection in the minimally invasive era is scarce. The aim of this population-based study was to provide more insight into the permanent stoma rate with interhospital variability (IHV) depending on surgical technique, with pelvic sepsis, unplanned reinterventions and readmissions as secondary outcomes. Method: Patients who underwent open or minimally invasive resection of rectal cancer (lower border below the sigmoid take-off) in 67 Dutch centres in 2016 were included in this cross-sectional cohort study. Results: Among 2530 patients, 1470 underwent a restorative resection (58%), 356 a Hartmann's procedure (14%, IHV 0%–42%) and 704 an abdominoperineal resection (28%, IHV 3%–60%). Median follow-up was 51 months. The overall permanent stoma rate at last follow-up was 50% (IHV 13%–79%) and the unintentional permanent stoma rate, permanent stoma after a restorative procedure or an unplanned Hartmann's procedure, was 11% (IHV 0%–29%). A total of 2165 patients (86%) underwent a minimally invasive resection: 1760 conventional (81%), 170 transanal (8%) and 235 robot-assisted (11%). An anastomosis was created in 59%, 80% and 66%, with corresponding unintentional permanent stoma rates of 12%, 24% and 14% (p = 0.001), respectively. When corrected for age, American Society of Anesthesiologists classification, cTNM, distance to the anorectal junction and neoadjuvant (chemo)radiotherapy, the minimally invasive technique was not associated with an unintended permanent stoma (p = 0.071) after a restorative procedure. Conclusion: A remarkable IHV in the permanent stoma rate after rectal cancer resection was found. No beneficial influence of transanal or robot-assisted laparoscopy on the unintentional permanent stoma rate was found, although this might be caused by the surgical learning curve. A reduction in IHV and improving preoperative counselling for decision-making for restorative procedures are required.</p

Effectiveness of Emotional Memory Reactivation vs Control Memory Reactivation Before Electroconvulsive Therapy in Adult Patients With Depressive Disorder A Randomized Clinical Trial:A Randomized Clinical Trial

Importance: Although electroconvulsive therapy (ECT) is often effective, approximately half of patients with depression undergoing ECT do not benefit sufficiently, and relapse rates are high. ECT sessions have been shown to weaken reactivated memories. The effect of emotional memory retrieval on cognitive schemas remains unknown. Objective: To assess whether emotional memory retrieval just before patients receive ECT sessions weakens underlying cognitive schemas, improves ECT effectiveness, increases ECT response, and reduces relapse rates. Design, Setting, and Participants: In this multicenter randomized clinical trial conducted from 2014 to 2018 in the departments of psychiatry in 3 hospitals in the Netherlands, 72 participants were randomized 1:1 to 2 parallel groups to receive either emotional memory reactivation (EMR-ECT) or control memory reactivation (CMR-ECT) interventions before ECT sessions. The Hamilton Depression Rating Scale (HDRS [total score range: 0-52, with 0-7 indicating no depression and ≥24 indicating severe depression]) was used to measure symptoms of depression during and after ECT, with a 6-month follow-up period. Participants were between ages 18 and 70 years with a primary diagnosis of unipolar major depressive disorder (MDD) according to the Diagnostic and Statistical Manual of Mental Disorders (Fourth Edition, Text Revision) and in whom ECT was indicated. Data analysis was performed from July to November 2019. Interventions: EMR-ECT or CMR-ECT interventions prior to ECT sessions. Main Outcomes and Measures: Depression scores and relapse rates within 6 months were assessed with the HDRS and analyzed using logistic and linear multiple regression analyses. Results: A total of 66 patients (mean [SD] age, 49.3 [12.3] years; 39 [59.1%] women) were randomized to the EMR-ECT group (n = 32) or the CMR-ECT group (n = 34). Regardless of the memory intervention, 42.4% (28 of 66) of patients responded (≥50% decrease of symptom severity on the HDRS). Of patients who responded, 39.3% (11 of 28) relapsed within 6 months. Remission rates (CMR-ECT group, 29.4% [10 of 34] vs EMR-ECT group, 25.0% [8 of 32]; P = .58), mean (SD) HDRS scores after the ECT course (CMR-ECT group, 14.6 [8.6] vs EMR-ECT group, 14.9 [8.8]; P = .88), total mean (SD) number of required ECT sessions for response (CMR-ECT group, 14.9 [7.9] vs EMR-ECT group, 15.6 [7.3]; P = .39), and relapse rates (CMR-ECT group, 46.7% [7 of 15] vs EMR-ECT group, 30.8% [4 of 13]; P = .33) were not significantly altered by the intervention. Conclusions and Relevance: Study findings suggest that the EMR-ECT intervention just before patient receipt of ECT for depression did not improve effectiveness, increase speed of response, or reduce relapse rates after the ECT course compared with patients receiving CMR-ECT. Trial Registration: Trialregister.nl Identifier: NL4289