Clinicopathological analysis of primary epithelial appendiceal neoplasms

Appendiceal carcinomas are classified into three distinct histopathological disease entities: disseminated peritoneal adenomucinosis (DPAM), peritoneal mucinous carcinomatosis (PMCA), or peritoneal mucinous carcinomatosis with intermediate or discorant features (PMCA I/D). The treatment of appendiceal tumors should be based on accurate histopathological classification, per previously reported case series. The objective of this study was to evaluate the clinicopathologic presentation and outcome of patients with appendiceal tumors treated at our institution over a 15-year period. We identified patients with appendiceal tumors diagnosed or treated at our institution from January 1989 through May 2004. Chart review for age, gender, signs and symptoms at diagnosis, and treatment was performed. Review of the pathologic specimens was performed and tumors were classified as DPAM, PMCA I/D, or PMCA. Forty patients were identified (median age 52.5 years; males 38%). The number of patients with DPAM, PMCA I/D, and PMCA was 15 (38%), 6 (15%), and 18 (46%), respectively. Peritoneal involvement was seen in 11 (73%) of patients with DPAM, 5 (83%) of PMCA I/D, and 11 (61%) of PMCA. The median survival for patients with DPAM, PMCA I/D, and PMCA was 7.7 years (90% CI: 2.9—upper limit not estimable), 1.2 years (90% CI: 0.9–1.6), and 0.7 years (90% CI: 0.4–1.5), respectively. The difference in survival across the three groups was statistically significant. Three distinct histopathological disease entities exist in appendiceal tumors. The prognosis and management of these tumors should be based on the extent of disease and pathologic diagnosis.     

Biodegradable-Polymer Biolimus-Eluting Stents versus Durable-Polymer Everolimus-Eluting Stents at One-Year Follow-Up: A Registry-Based Cohort Study

We compared outcomes of percutaneous coronary intervention patients who received biodegradable-polymer biolimus-eluting stents with those who received durable-polymer everolimus-eluting stents.At Tehran Heart Center, we performed a retrospective analysis of the data from January 2007 through December 2011 on 3,270 consecutive patients with coronary artery disease who underwent percutaneous coronary intervention with the biodegradable-polymer biolimus-eluting stent or the durable-polymer everolimus-eluting stent. We excluded patients with histories of coronary artery bypass grafting or percutaneous coronary intervention, acute ST-segment-elevation myocardial infarction, or the implantation of 2 different stent types. Patients were monitored for 12 months. The primary endpoint was a major adverse cardiac event, defined as a composite of death, nonfatal myocardial infarction, and target-vessel and target-lesion revascularization.Durable-polymer everolimus-eluting stents were implanted in 2,648 (81%) and biodegradable-polymer biolimus-eluting stents in 622 (19%) of the study population. There was no significant difference between the 2 groups (2.7% vs 2.7%; P=0.984) in the incidence of major adverse cardiac events. The cumulative adjusted probability of major adverse cardiac events in the biodegradable-polymer biolimus-eluting stent group did not differ from that of such events in the durable-polymer everolimus-eluting stent group (hazard ratio=0.768; 95% confidence interval, 0.421–1.44; P=0.388).We conclude that in our patients the biodegradable-polymer biolimus-eluting stent was as effective and safe, during the 12-month follow-up period, as was the durable-polymer everolimus-eluting stent.     

Influence of cone beam CT scanning parameters on grey value measurements at an implant site

Objectives:

The aim of this study was to determine the grey value variation at the implant site with different scan settings, including field of view (FOV), spatial resolution, number of projections, exposure time and dose selections in two cone beam CT (CBCT) systems and to compare the results with those obtained from a multislice CT system.

Methods:

A partially edentulous human mandibular cadaver was scanned by three CT modalities: multislice CT (MSCT) (Philips, Best, the Netherlands), and two CBCT systems: (Accuitomo 170^®, Morita, Japan) and (NewTom 5G^®, QR, Verona, Italy). Using different scan settings 36 and 24 scans were obtained from the Accuitomo and the NewTom, respectively. The scans were converted to digital imaging and communications in medicine 3 format. The analysis of the data was performed using 3Diagnosys^® software (v. 3.1, 3diemme, Cantù, Italy) and Geomagic studio^® 2012 (Morrisville, NC). On the MSCT scan, one probe designating the site for pre-operative implant placement was inserted. The inserted probe on MSCT was transformed to the same region on each CBCT scan using a volume-based three-dimensional registration algorithm. The mean voxel grey value of the region around the probe was derived separately for each CBCT. The influence of scanning parameters on the measured mean voxel grey values was assessed.

Results:

Grey values in both CBCT systems significantly deviated from Hounsfield unit values measured with MSCT (p = 0.0001). In both CBCT systems, scan FOV and spatial resolution selections had a statistically significant influence on grey value measurements (p = 0.0001). The number of projections selection had a statistically significant influence in the Accuitomo system (p = 0.0001) while exposure time and dose selections had no statistically significant influence on grey value measurements in the NewTom (p = 0.43 and p = 0.37, respectively).

Conclusions:

Grey-level values from CBCT images are influenced by device and scanning settings.     

Evaluation of nonlinear frequency compression: Clinical outcomes

This study evaluated prototype multichannel nonlinear frequency compression (NFC) signal processing on listeners with high-frequency hearing loss. This signal processor applies NFC above a cut-off frequency. The participants were hearing-impaired adults (13) and children (11) with sloping, high-frequency hearing loss. Multiple outcome measures were repeated using a modified withdrawal design. These included speech sound detection, speech recognition, and self-reported preference measures. Group level results provide evidence of significant improvement of consonant and plural recognition when NFC was enabled. Vowel recognition did not change significantly. Analysis of individual results allowed for exploration of individual factors contributing to benefit received from NFC processing. Findings suggest that NFC processing can improve high frequency speech detection and speech recognition ability for adult and child listeners. Variability in individual outcomes related to factors such as degree and configuration of hearing loss, age of participant, and type of outcome measure.     

A Hybrid Algorithm for Prediction of Varying Heart Rate Motion in Computer-Assisted Beating Heart Surgery

An essential requirement for performing robotic assisted surgery on a freely beating heart is a prediction algorithm which can estimate the future trajectory of the heart in the varying heart rate (HR) conditions of real surgery with a high accuracy. In this study, a hybrid amplitude modulation- (AM) and autoregressive- (AR) based algorithm was developed to enable estimating the global and local oscillations of the beating heart, raised from its major and minor physiological activities. The AM model was equipped with an estimator of the heartbeat frequency to compensate for the HR variations. The RMS of the prediction errors of the hybrid algorithm was in the range of 165–361 μm for the varying HR motion, 21% less than that of the single AM model. With the capability of providing highly accurate predictions in a wide range of HR variation, the hybrid model is promising for practical use in robotic assisted beating heart surgery.     

Effects of adjuvant chemotherapy and radiation on overall survival in children with choroid plexus carcinoma

Choroid plexus carcinoma (CPCs) is a rare, malignant, primary brain tumor with a poor prognosis. Currently, there is no consensus on the use of adjuvant therapy, and few large-scale studies focus exclusively on the pediatric population. We performed a comprehensive systematic review of pediatric CPCs to determine the effects of various adjuvant therapy modalities on overall survival (OS). A literature search was performed to identify studies reporting children with CPC who underwent surgical resection. Only patients who had clearly received adjuvant therapy, or were described as not selected for adjuvant therapy were analyzed in our comparison groups. Kaplan–Meier and multivariate Cox regression survival analyses were performed to determine the effects of different types of adjuvant therapies on OS. A total of 135 children (age ≤ 18 years) with CPC who had known adjuvant therapy status and OS were identified from 53 articles. Kaplan–Meier analysis showed that while adjuvant therapy overall improved OS (p = 0.001), different modes of adjuvant therapies had varying effects on OS (p = 0.034). Specifically, combined chemo-radiotherapy as well as chemotherapy alone improved OS (p = 0.001), but radiation did not (p = 0.129). Multivariate Cox proportional hazard model adjusting for confounding factors showed that combined therapy was associated with better OS compared to chemotherapy alone (HR: 0.291, p = 0.027). Both chemotherapy alone and combined chemo-radiation improved OS independent of age, gender, tumor location and extent of resection, while radiation alone did not.     

The effect of scan parameters on cone beam CT trabecular bone microstructural measurements of the human mandible

The objective of this study was to investigate the effect of different cone beam CT scan parameters on trabecular bone microstructure measurements. A human mandibular cadaver was scanned using a cone beam CT (3D Accuitomo 170; J.Morita, Kyota, Japan). 20 cone beam CT images were obtained using 5 different fields of view (4×4 cm, 6×6 cm, 8×8 cm, 10×10 cm and 10×5 cm), 2 types of rotation steps (180° and 360°) and 2 scanning resolutions (standard and high). Image analysis software was used to assess the trabecular bone microstructural parameters (number, thickness and spacing). All parameters were measured twice by one trained observer. Intraclass correlation coefficients showed high intraobserver repeatability (intraclass correlation coefficient, 0.95–0.97) in all parameters across all tested scan parameters. Trabecular bone microstructural measurements varied significantly, especially in smaller fields of view (p = 0.001). There was no significant difference in the trabecular parameters when using different resolutions (number, p = 0.988; thickness, p = 0.960; spacing, p = 0.831) and rotation steps (number, p = 1.000; thickness, p = 0.954; spacing, p = 0.759). The scan field of view significantly influences the trabecular bone microstructure measurements. Rotation steps (180° or 360°) and resolution (standard or high) selections are not relevant.