Search

Background: Novel on‐board CBCT allows for improved image quality and Hounsfield unit accuracy. When coupled with online adaptive tools, this may have potential to allow for simulation and treatment to be completed in a single on‐table session. Purpose: To study the feasibility of a high‐efficiency radiotherapy treatment workflow without the use of a separate session for simulation imaging. The dosimetric accuracy, overall efficiency, and technical feasibility were used to evaluate the clinical potential of CT simulation‐free adaptive radiotherapy. Methods: Varian's Ethos adaptive radiotherapy treatment platform was upgraded with a novel CBCT system, HyperSight which reports image quality and Hounsfield unit accuracy specifications comparable to standard fan‐beam CT. Using in‐house developed MATLAB software, CBCT images were imported into the system and used for planning. Two test cases were completed on anthropomorphic phantoms equipped with small volume ion chambers (cross‐calibrated to an ADCL traceable dose standard) to evaluate the feasibility and accuracy of the workflows. A simulated palliative spine treatment was planned with 8 Gy in one fraction, and an intact prostate treatment was planned with 60 Gy in 20 fractions. The CBCTs were acquired using HyperSight with default thorax and pelvis imaging protocols and reconstructed using an iterative algorithm with scatter removal, iCBCT Acuros. CBCTs were used for contouring and planning, and treatment was delivered via an online adaptive workflow. In addition, an external dosimetry audit was completed using only on‐board CBCT imaging in an end‐to‐end head and neck phantom irradiation. Results: An extended‐field CBCT acquisition can be acquired in 12 s, in addition to the time for longitudinal table shifts, and reconstructed in approximately 1 min. The superior‐inferior extent for the CBCT planning images was 38.2 cm, which captured the full extent of relevant anatomy. The contouring and treatment planning for the spine and prostate were completed in 30 and 18 min, respectively. The dosimetric agreement between ion chamber measurements and the treatment plan was within a range of −1.4 to 1.6%, and a mean and standard deviation of 0.41 ± 1.16%. All metrics used in the external audit met the passing criteria, and the dosimetric comparison between fan‐beam and CBCT techniques had a gamma passing rate of 99.0% with a criteria of 2%/2 mm. Conclusion: Using an in‐house workflow, CT simulation‐free radiation therapy was shown to be feasible with acceptable workflow efficiency and dosimetric accuracy. This approach may be particularly applicable for urgent palliative treatments. With the availability of software to enable this workflow, and the continued advancement of on‐treatment adaptation, single‐visit radiation therapy may replace current practice for some clinical indications. [ABSTRACT FROM AUTHOR]

Stream temperature governs many aquatic ecosystem processes and plays a key role in determining the distribution of cold‐water amphibians and cool‐ and cold‐water fish, including salmonids. Decades of research have focused on the effects of forestry and forest disturbance on stream temperature, and new projects are underway or being planned in jurisdictions including the Provinces of Alberta and British Columbia, Canada, and Washington State, USA. The objective of this paper is to provide a critical review of methodologies employed in previous studies. The review initially focuses on the range of metrics used to quantify stream thermal regimes and the factors that control stream temperature variability in time and space, then focuses on sampling and analytical methodologies used to quantify stream temperature response to forestry activity and forest disturbance. Empirical methods include sampling in time, space, or both, and may or may not include pre‐ and post‐harvest data. Process‐based mechanistic and hybrid empirical‐mechanistic models have also been applied. The advantages and disadvantages of these approaches are discussed, and recommendations provided to support the design and execution of future studies. [ABSTRACT FROM AUTHOR]

Background: Intensity modulated radiotherapy (IMRT) for head and neck cancer has led to a reduction in radiotherapy doses to normal tissues, like the salivary glands, while maintaining high rates of local control. Oral mucosal and skin toxicity is still a major source of treatment—related morbidity, occurring in most patients. Purpose: We conducted a dosimetric feasibility study with the goal of creating a methodology that could theoretically reduce the dose of radiation to skin and oral mucosa, while maintaining comparable avoidance of other organs at risk, and planning target volume (PTV) coverage. Methods: The clinical plans of patients treated previously were replanned using coplanar VMAT arcs on a TrueBeam STx using the photon optimizer (PO) version 15.6 and the Acuros XB dose calculation algorithm. Comparisons were made between three methodologies: "Conventional," "Skin Sparing" and a skin/mucosa avoiding ("SMART") technique, with dose metrics being compared using analysis of variance, with a Bonferroni correction to account for multiple pairwise comparisons. The maximum grade of mucositis and radiation dermatitis during treatment was correlated to different dose‐volume metrics to predict what could be clinically meaningful. Results: Sixteen patients met the study criteria and were replanned using the skin sparing and SMART techniques. Maximum doses to the skin sparing structure were reduced from 64.2 Gy to 56.6 and 55.9 Gy, in the skin sparing and SMART plans (p < 0.0001), and mean doses reduced from 26.7 Gy to 20.0 and 20.2 Gy, respectively (p < 0.0001). Maximum doses to the oral cavity structure were not reduced by either technique, however mean dose to the oral cavity structure was reduced from 39.03 Gy to 33.5 Gy by the SMART technique (p < 0.0001). There was a slight reduction in PTV_High coverage by the V95% in the SMART plans (99.52% vs. 98.79%, p = 0.0073), and a similar slight reduction in PTV_Low coverage by the V95% by both the skin sparing and SMART plans (99.74% vs. 97.89% vs. 97.42%, p < 0.0001). Maximum doses to organs at risk were not statistically different between techniques. Dose to oral cavity and maximum grade experienced during radiotherapy correlated. The Spearman correlation coefficient for dose to 20%, 50%, and 80% of the volume of oral cavity was 0.5 (p = 0.048), 0.64 (p = 0.007), and 0.62 (p = 0.010), respectively. Skin toxicity grade was only found to be correlated with the D20% of the skin sparing structure (Spearman correlation coefficient of 0.58, p = 0.0177). Conclusion: The SMART technique appears to be able to reduce maximum and mean skin dose, as well as mean oral cavity doses, while only slightly reducing PTV coverage, with acceptable OAR doses. We feel the improvements warrant investigation in a clinical trial. [ABSTRACT FROM AUTHOR]

Introduction: Radiotherapy deliveries with dynamic couch motions that shorten the source‐to‐axis distance (SAD) on a C‐arm linac have the potential to increase treatment efficiency through the increase of the effective dose rate. In this investigation, we convert clinically deliverable volumetric modulated arc therapy (VMAT) and dynamic conformal arc (DCA) plans for cranial radiosurgery into virtual isocenter plans through implementation of couch trajectories that maintain the target at a shortened but variable SAD throughout treatment. Materials and Methods: A randomly sampled population of patients treated with cranial radiosurgery from within the last three years were separated into groups with one, two, and three lesions. All plans had a single isocenter (regardless of number of targets), and a single prescription dose. Patient treatment plans were converted from their original delivery at a standard isocenter to a dynamic virtual isocenter in MATLAB. The virtual isocenter plan featured a variable isocenter position based upon the closest achievable source‐to‐target distance (referred to herein as a virtual source‐to‐axis distance [vSAD]) which avoided collision zones on a TrueBeam STx platform. Apertures were magnified according to the vSAD and monitor units at a given control point were scaled based on the inverse square law. Doses were calculated for the plans with a virtual isocenter in the Eclipse (v13.6.23) treatment planning system (TPS) and were compared with the clinical plans. Plan metrics (MU, Paddick conformity index, gradient index, and the volume receiving 12 Gy or more), normal brain dose–volume differences, as well as maximum doses received by organs at risk (OARs) were assessed. The values were compared between standard and virtual isocenter plans with Wilcoxon Sign Ranked tests to determine significance. A subset of the plans were mapped to the MAX‐HD anthropomorphic phantom which contained an insert housing EBT3 GafChromic film and a PTW 31010 microion chamber for dose verification on a linac. Results: Delivering plans at a virtual isocenter resulted in an average reduction of 20.9% (p = 3×10−6) and 20.6% (p = 3.0×10−6) of MUs across all VMAT and all DCA plans, respectively. There was no significant change in OAR max doses received by plans delivered at a virtual isocenter. The low dose wash (1.0–2.0 Gy or 5–11% of the prescription dose) was increased (by approximately 20 cc) for plans with three lesions. This was equivalent to a 2.7%–3.8% volumetric increase in normal tissue receiving the respective dose level when comparing the plan with a virtual isocenter to a plan with a standard isocenter. Gamma pass rates with a 5%/1mm analysis criteria were 96.40% ± 2.90% and 95.07% ± 3.10% for deliveries at standard and virtual isocenter, respectively. Absolute point dose agreements were within −0.36% ± 3.45% and −0.55% ± 3.39% for deliveries at a standard and virtual isocenter, respectively. Potential time savings per arc were found to have linear relationship with the monitor units delivered per arc (savings of 0.009 s/MU with an r2 = 0.866 when fit to plans with a single lesion). Conclusions: Converting clinical plans at standard isocenter to a virtual isocenter design did not show any losses to plan quality while simultaneously improving treatment efficiency through MU reductions. [ABSTRACT FROM AUTHOR]

This chapter presents the leadership journeys of five faculty who participated in the SAGE 2YC: Faculty as Change Agents project. These faculty stories illustrate the influence of the project on their leadership and work as mid‐level administrative or grassroots leaders. Key to the project was the explicit inclusion of leadership development in the professional development (PD). Learning about organizational frames and leadership approaches, the experience of faculty participants designing and leading their own workshops, and the resulting community of practice contributed to the leadership development of faculty participants. Implications and recommendations for leadership development of faculty members, critically important for colleges, concludes the chapter. [ABSTRACT FROM AUTHOR]

This chapter presents the experiences of adjunct faculty in the SAGE 2YC: Faculty as Change Agents project through the stories of five participants who share the influence of the project on them and their work. We describe the professional development that occurred in the project, which included learning with colleagues from across the country, implementing changes in their classroom teaching and beyond, and leading follow‐on workshops in teams on campus and/or in the region. The participant stories illustrate how the project gave them agency and validated their work. Adjunct faculty make important contributions to student and faculty success, and there is power in engaging adjunct faculty as leaders and change agents and fully realizing their potential. [ABSTRACT FROM AUTHOR]

Drawing from examples of career development initiatives implemented by SAGE 2YC Faculty Change Agents, this chapter illustrates the role of career development in supporting the success of all community college students and guides faculty, administrators, and professional societies on how to advance student career development on a variety of scales. Career development as an integral component of community college science courses has major implications for increasing the diversity of science professionals, conveying the importance of science and scientific literacy in career sectors within and outside of the sciences, reducing equity gaps in students' career development as undergraduates, and facilitating skill‐building necessary for the workforce. We urge community college science faculty and administrators to consider the powerful impact that career skill‐building and career exploration have on students and encourage the adoption of career development activities at the classroom, program, and institutional levels. [ABSTRACT FROM AUTHOR]

Purpose: This work generates multi‐metastases cranial stereotactic radiosurgery/radiotherapy (SRS/SRT) plans using a novel treatment planning technique in which dynamic couch, collimator, and gantry trajectories are used with periodic binary target collimation. The performance of this planning technique is evaluated against conventional volumetric arc therapy (VMAT) planning in terms of various dose and plan quality metrics. Methods: A 3D cost space (referred to herein as the combined optimization of dynamic axes or CODA cube) was calculated based on an overlap between targets and organs‐at‐risk (OARs) and uncollimated areas between targets (island blocking) for all combinations of couch, gantry, and collimator angles. Gradient descent through the cube was applied to determine dynamic trajectories. At each control point (CP), each target can either be conformally treated or blocked by the multi‐leaf collimator (referred to as intra‐arc binary collimation, iABC). Simulated annealing was used to optimize the collimation patterns throughout the arcs as well as the monitor units (MUs) delivered at each CP. Seven previously treated VMAT plans were selected for comparison against the CODA–iABC planning technique. Two CODA–iABC plans were developed: a single gantry arc plan and a plan with one gantry arc and two couch arcs. Plan quality comparison metrics included maximum and mean dose to OARs (brainstem, chiasm, optic nerves, eyes, and lenses), the volume of normal brain receiving 12 Gy (V12Gy), total MUs, target conformity, and dose‐gradient index. Results: Treatment plans generated with 1‐arc CODA–iABC plans delivered an average of 21% and 30% higher maximum and mean doses to brainstem, respectively, when compared to VMAT plans. Treatment plans generated with 3‐arc CODA–iABC used an average of 24% fewer MUs and resulted in an average reduction of 48% maximum dose and 50% mean dose to the OARs, when compared to VMAT. Target conformity values were worse in both CODA–iABC plans than VMAT by an average of 35% and 15%, respectively. There are no significant differences in V12Gy for all three planning techniques; however, 3‐arc CODA–iABC is more effective at reducing dose to normal brain in the low‐dose region (<12 Gy). Conclusion: CODA–iABC is a novel planning technique that has been developed to automatically generate patient‐specific multi‐axis trajectories for multiple metastases cranial SRS/SRT. This work has demonstrated the feasibility of planning with this novel method. The 1‐arc CODA–iABC planning technique is slightly dosimetric inferior to VMAT. With an increased sampling of a three‐dimensional CODA cube by using a 3‐arc CODA–iABC technique, there was improved total dose sparing to all the OARs and increased MU efficiency, but with a cost in target conformity, when compared to VMAT. [ABSTRACT FROM AUTHOR]

Purpose: Gamma Knife Icon (GKI) enables a user‐defined gating threshold for intrafraction motion during stereotactic radiosurgery (SRS). An optimal threshold would ensure dosimetric fidelity of the planned distribution and minimize treatment time extension by gating. A prediction of motion characteristics for a patient based on a retrospective database of motion traces could be beneficial to evaluating the choice of gating threshold. A short acquisition of motion may help to define a personalized threshold that balances dosimetric accuracy and treatment length. This study aims to evaluate the performance of a prediction of motion and the resultant dosimetric consequences for a range of motion gating thresholds. Methods: A database of 2552 motion traces (776 patients) was analyzed using previously published methods to characterize patient intrafraction motion on the GKI. For a selection of six fractionated SRS patient cases (two patients with single brain metastasis, four vestibular schwannomas), a 10‐min sample of motion was used to classify motion and identify traces in the database with similar metrics. The similar motion traces were used to perform a predictive reconstruction of the selected patient's delivered dose for a range of motion thresholds. The remaining fractions were reconstructed and compared to that predicted. From the six cases, 26 fractions were used to predict the number of interruptions (n = 26), change in target coverage (n = 26), and change in brainstem maximum dose (vestibular cases only, n = 20). The difference between mean predicted and reconstructed values was compared for accuracy. Results: The difference between mean prediction and reconstructed values was 0.32 ± 0.38% in target coverage, 2.36 ± 5.06 interruptions, and 0.15 ± 0.24 Gy for the brainstem maximum dose. Sixty‐seven of the 72 predictions (26 coverage, 26 interruptions, and 20 brainstem maximum dose) were within one standard deviation of the predicted mean. Conclusions: Large databases of motion traces were used to characterize patient performance and predict motion performance. Dosimetric deterioration due to motion and extension of treatment duration can be predicted in some cases using only a short acquisition of motion and the treatment plan. This reconstruction may provide benefit in generating a patient‐specific motion threshold. [ABSTRACT FROM AUTHOR]

This article reviews a virtual professional development program for STEM faculty conducted in 2020 in which, due to COVID, faculty participants had to adjust their teaching practices. The study found that the program's structure, focus, and ability to foster community helped sustain faculty members. Participants shared lessons learned through virtual workshops they led for others on their campuses. [ABSTRACT FROM AUTHOR]

This chapter summarizes the varied disciplinary society structures and synthesizes the ways to enhance the relationship between the disciplinary societies and their community college partners. [ABSTRACT FROM AUTHOR]

This chapter addresses the engagement of geoscience societies with community college faculty, traces the emergence of the Geo2YC Division as a model for others, and provides examples that focus on ways to build a professional community. [ABSTRACT FROM AUTHOR]

Purpose: To develop a novel system for patient‐specific combined optimization of couch, collimator, and gantry angles for use in volumetric modulated arc therapy (VMAT) treatment planning. The system was designed to produce highly compact dose distributions by extensively sampling the 4π space. Automated fixed couch trajectory planning was used to reduce normal tissue doses by avoiding beams‐eye‐view (BEV) overlap with organs‐at‐risk (OARs) and improve monitor unit (MU) efficiency through collimator angle optimization. Methods: By merging distinct BEV objective functions used to optimize the couch rotation angle and collimator angle, a three‐dimensional (3D) cost space (the CODA cube) was constructed with axes of gantry, couch, and collimator rotation angles. At each voxel in this CODA cube, the cost of implementing this combination of axes positions in fixed couch trajectories was quantified. The CODA cube was sampled and explored using a modified constrained Bellman‐Ford algorithm to suggest low‐cost fixed candidate arcs on each plane of the space, from which 10‐arcs are chosen throughout the 3D space using a k‐means clustering algorithm. These fixed couch trajectories were then imported into the Eclipse treatment planning system (v.11) and inverse‐optimized according to clinical standards. Eight artificial cranial targets were contoured in a test‐patient anatomy, and seven treatment plans were generated from combinations of three and four targets. The CODA cube optimized plans were compared to standard 4‐arc VMAT plans for cranial stereotactic radiotherapy/surgery that were optimized for the same sets of targets; maximum dose to each OAR, V12Gy to normal brain, conformity, and total MUs were compared. Both planning methods were inverse‐optimized with identical dosimetric objectives. Results: CODA plans resulted in a reduction in maximum dose to OARs of 20.6% (P < 0.01), with maximum brainstem dose decreased by 2.63 Gy (P = 0.031) on average when compared to the standard arc arrangement. The mean reduction in total MU was 8.6% (P = 0.156), the mean increase in the inverse of the van't Riet conformation number was 0.1%, (P = 0.67) and the mean decrease in normal brain tissue receiving 12 Gy or higher was 3.9% (P = 0.16), when compared to the standard VMAT arc configuration (n = 7). Conclusions: The optimization of couch, collimator, and gantry angles simultaneously using a 3D optimization space achieved improvement on multiple clinical metrics when compared to the standard VMAT arc configuration. A statistically significant sparing to OAR maximum doses was seen. Combining these optimizations may yield superior results to independent optimization. [ABSTRACT FROM AUTHOR]

The article offers information on the survival of women with early-stage cervical cancer with minimal access and open surgery. It discusses the introduction of a laparoscopically assisted radical vaginal hysterectomy for radical cervical surgery. It mentions the comprehensive analysis of the outcomes for women being treated for stage 1B1 cancers. It also mentions the treatment of women with radical hysterectomy with a laparoscopic or robotic approach.

In Chapter 7, a community college historian summarizes projects in two national associations to overcome elitism and involve community college faculty in content and pedagogical innovations. In Chapter 10, psychology faculty and national organization staff investigate how the national association supports the psychology curriculum and the leadership development needs of community college faculty. In Chapter 2, chemistry faculty describe conferences organized by the Two-Year College Chemistry Consortium and report the results of a new survey of community college faculty about potential support from the national disciplinary association. [Extracted from the article]

Purpose: To design and implement a novel treatment planning algorithm based on a modification of dynamic conformal arc (DCA) therapy for the treatment of multiple cranial metastases with variable prescription doses. Methods: A workflow was developed in which separate dose matrices were calculated for each target at each control point (i.e., the multileaf collimator (MLC) was fit conformally to that single target). A cost function was used to quantify the relative contributions of each dose matrix in the plan to the overall plan objectives. Simulated annealing was used to allow for the inclusion or exclusion of individual dose matrices at each control point. The exclusion of individual targets at a given control point is termed intra‐arc binary collimation (iABC) in this work and is accomplished by closing the MLCs over the target for a duration specified by simulated annealing optimization. Dynamic collimator motions were employed to minimize the variation between the idealized dose matrices (i.e., perfectly collimated targets) and actual dose matrices (i.e., MLC apertures that include quantities of nontarget tissue due to the relative orientations of targets in the field). An additional simulated annealing optimization was performed to weight the relative contributions of dose at each control point [referred to as the monitor unit distribution (MUD)] to improve compliance with plan objectives. The algorithm was tested on seven previously treated multiple metastases patients and plans were compared to the clinically treated VMAT plans. Results: Treatment plans generated with iABC used an average of 2716 (34%) fewer MU in the total plan than VMAT (P = 0.01). All normal tissue metrics for all plans and all patients were clinically acceptable. There were no statistically significant differences in any normal tissue dose metrics. Normalized prescription target coverage accuracy for all targets was 3% better on average for VMAT plans when compared to iABC (P = 0.07), and 14% better on average for iABC when compared to optimized DCA (P = 0.03). Conclusion: A novel method of aperture and dose distribution design has been developed to significantly increase the MU efficiency of single isocenter treatment of multiple metastases with variable prescription doses when compared to VMAT, and which improves target coverage accuracy significantly when compared to optimized DCA. By applying a DCA approach to subsets of targets across control points, a hybrid method of treatment delivery has been developed that combines the efficiency of dynamic conformal treatments and the dosimetric flexibility of VMAT. [ABSTRACT FROM AUTHOR]

Purpose: To develop an algorithm for dynamic collimator positioning to optimize beam's eye view (BEV) fitting of targets in dynamic conformal arc (DCA)‐based radiotherapy procedures, of particular use in multiple metastases stereotactic radiosurgery procedures. Methods: A trajectory algorithm was developed to dynamically modify the angle of the collimator as a function of arc‐based control point to provide optimized collimation of target volume(s). Central to this algorithm is a concept denoted herein as “whitespace” defined as any nontarget area in the BEV that is not covered by any collimation system and is open to exposure from the radiation beam. Calculating whitespace at all collimator angles and every control point, a two‐dimensional topographical map depicting the tightness‐of‐fit of the MLC was generated. A bidirectional gradient trajectory algorithm identified a number of candidate trajectories of continuous collimator motion. Minimization of integrated whitespace was used to identify an optimal solution for the navigation of the parameter space. Plans with dynamic collimator trajectories were designed for multiple metastases targets and were compared with fixed collimator angle dynamic conformal arc (DCA) plans and standard VMAT plans. Results: Algorithm validation was performed on simple test cases with known solutions. The whitespace metric showed a strong correlation (R2 = 0.90) with mean dose to proximal normal tissue. Seventeen cases were studied using our algorithm to generate dynamic conformal arc (DCA) plans with optimized collimator trajectories for three and four target SRS patients and comparing them to DCA plans generated with optimized fixed collimator angles per arc and standard VMAT plans generated via template. Optimized collimator trajectories were found to produce a reduction in monitor units of up to 49.7 ± 5.1% when compared to VMAT across 17 patients, and all organ‐at‐risk and normal brain metrics were found to be superior or comparable. Conclusion: Dynamic collimator trajectories have the potential to improve DCA deliveries through increased efficiency, especially in the treatment of multiple cranial metastases. Implementation of this technology should not be hindered by mechanical safety considerations as collimator motions do not modify or introduce any new risks of collisions with patients. [ABSTRACT FROM AUTHOR]

Objective. To compare the safety, efficacy, and direct cost during the introduction of laparoscopic radical hysterectomy within an enhanced recovery pathway. Methods. A 1 : 1 single centre retrospective case control study of 36 propensity matched pairs of patients receiving open or laparoscopic surgery for early cervical cancer. Results. There were no significant differences in the baseline characteristics of the two cohorts. Open surgery cohort had significantly higher intraoperative blood loss (189 versus 934 mL) and longer postoperative hospital stay (2.3 versus 4.1 days). Although no significant difference in the intraoperative or postoperative complications was found more urinary tract injuries were recorded in the laparoscopic cohort. Laparoscopic surgery had significantly longer duration (206 versus 159 minutes), lower lymph node harvest (12.6 versus 16.9), and slower bladder function recovery. The median direct hospital cost was £4850 for laparoscopic radical hysterectomy and £4400 for open surgery. Conclusions. Laparoscopic radical hysterectomy can be safely introduced in an enhanced recovery environment without significant increase in perioperative morbidity. The 10% higher direct hospital cost is not statistically significant and is expected to even out when indirect costs are included. [ABSTRACT FROM AUTHOR]

Purpose To investigate potential dosimetric improvements through the optimization of fixed-couch rotational position in cranial cancer stereotactic treatments. Methods Using previously delivered cranial stereotactic radiotherapy plans treated at the Nova Scotia Health Authority ( NSHA), we have redesigned the treatment arrangement to find the optimal couch rotation positions based on the reduction of overlap between organs-at-risk of exposure ( OARs) and target volume ( PTV). Maintaining the gantry arrangements from the delivered treatment, the couch positions were determined based on a cost function analysis of accumulation of overlap score from an equation developed by Yang et al. and refined by MacDonald et al. The algorithm incorporates factors for radiation dose sensitivities of each OAR, depth of both OARs and target ( PTV) volumes, and orthogonality of the 3D vector between OAR and PTV in the case of proximal OAR position. Results The plan evaluation was conducted on 16 acoustic neuroma patients treated with stereotactic radiotherapy plans at the NSHA. Maximum and mean doses to the OARs were reduced by approximately 14.30% ± 2.86% and 19.25% ± 2.10%, respectively, with application of this optimization technique as compared to the delivered treatment plans. In addition, PTV conformity and homogeneity were improved with application of this optimization technique. Conclusion This variation of the existing delivery techniques with guidance from a PTV- OAR overlap cost function analysis technique can yield significant dosimetric improvements with no increase to delivery or planning time. [ABSTRACT FROM AUTHOR]

Objective: To create a multidimensional tool to prognosticate long-term functional, cognitive, and quality of life outcomes after spontaneous subarachnoid hemorrhage (SAH) using data up to 48 hours after admission.Methods: Data were prospectively collected for 1,619 consecutive patients enrolled in the SAH outcome project July 1996 to March 2014. Linear models (LMs) were applied to identify factors associated with outcome in 1,526 patients with complete data. Twelve-month functional, cognitive, and quality of life outcomes were measured using the modified Rankin scale (mRS), Telephone Interview for Cognitive Status, and Sickness Impact Profile. Based on the LM residuals, we constructed the FRESH score (Functional Recovery Expected after Subarachnoid Hemorrhage). Score performance, discrimination, and internal validity were tested using the area under the receiver operating characteristic curve (AUC), Nagelkerke and Cox/Snell R(2) , and bootstrapping. For external validation, we used a control population of SAH patients from the CONSCIOUS-1 study (n = 413).Results: The FRESH score was composed of Hunt & Hess and APACHE-II physiologic scores on admission, age, and aneurysmal rebleed within 48 hours. Separate scores to prognosticate 1-year cognition (FRESH-cog) and quality of life (FRESH-quol) were developed controlling for education and premorbid disability. Poor functional outcome (mRS = 4-6) for score levels 1 through 9 respectively was present in 3, 6, 12, 38, 61, 83, 92, 98, and 100% at 1-year follow-up. Performance of FRESH (AUC = 0.90), FRESH-cog (AUC = 0.80), and FRESH-quol (AUC = 0.78) was high. External validation of our cohort using mRS as endpoint showed satisfactory results (AUC = 0.77). To allow for convenient score calculation, we built a smartphone app available for free download.Interpretation: FRESH is the first clinical tool to prognosticate long-term outcome after spontaneous SAH in a multidimensional manner. Ann Neurol 2016;80:46-58. [ABSTRACT FROM AUTHOR]

Purpose: To investigate potential improvement in external beam stereotactic radiation therapy plan quality for cranial cases using an optimized dynamic gantry and patient support couch motion trajectory, which could minimize exposure to sensitive healthy tissue. Methods: Anonymized patient anatomy and treatment plans of cranial cancer patients were used to quantify the geometric overlap between planning target volumes and organs-at-risk (OARs) based on their two-dimensional projection from source to a plane at isocenter as a function of gantry and couch angle. Published dose constraints were then used as weighting factors for the OARs to generate a map of couch-gantry coordinate space, indicating degree of overlap at each point in space. A couch-gantry collision space was generated by direct measurement on a linear accelerator and couch using an anthropomorphic solid-water phantom. A dynamic, fully customizable algorithm was written to generate a navigable ideal trajectory for the patient specific couch-gantry space. The advanced algorithm can be used to balance the implementation of absolute minimum values of overlap with the clinical practicality of large-scale couch motion and delivery time. Optimized cranial cancer treatment trajectories were compared to conventional treatment trajectories. Results: Comparison of optimized treatment trajectories with conventional treatment trajectories indicated an average decrease in mean dose to the OARs of 19% and an average decrease in maximum dose to the OARs of 12%. Degradation was seen for homogeneity index (6.14% ± 0.67%-5.48% ± 0.76%) and conformation number (0.82 ± 0.02-0.79 ± 0.02), but neither was statistically significant. Removal of OAR constraints from volumetric modulated arc therapy optimization reveals that reduction in dose to OARs is almost exclusively due to the optimized trajectory and not the OAR constraints. Conclusions: The authors' study indicated that simultaneous couch and gantry motion during radiation therapy to minimize the geometrical overlap in the beams-eye-view of target volumes and the organs-at-risk can have an appreciable dose reduction to organs-at-risk. [ABSTRACT FROM AUTHOR]

Background. Aneurysmal subarachnoid hemorrhage (aSAH) survivors commonly exhibit impairment on phonemic and semantic fluency tests; however, it is unclear which of the contributing cognitive processes are compromised in aSAH patients. One method of disentangling these processes is to compare initial word production, which is a rapid, semiautomatic, frontal-executive process, and late phase word production, which is dependent on more effortful retrieval and lexical size and requires a more distributed neural network. Methods. Seventy-two individuals with aSAH and twenty-five control subjects were tested on a cognitive battery including the phonemic and semantic fluency task. Demographic and clinical information was also collected. Results. Compared to control subjects, patients with aSAH were treated by clipping and those with multiple aneurysms were impaired across the duration of the phonemic test. Among patients treated by coiling, those with anterior communicating artery aneurysms or a neurological complication (intraventricular hemorrhage, vasospasm, and edema) showed worse output only in the last 45 seconds of the phonemic test. Patients performed comparably to control subjects on the semantic test. Conclusions. These results support a "diffuse damage" hypothesis of aSAH, indicated by late phase phonemic fluency impairment. Overall, the phonemic and semantic tests represent a viable, rapid clinical screening tool in the postoperative assessment of patients with aSAH. [ABSTRACT FROM AUTHOR]

Objective. The novel clinical prediction approach of Bayesian neural networks with fuzzy logic inferences is created and applied to derive prognostic decision rules in cerebral aneurysmal subarachnoid hemorrhage (aSAH). Methods. The approach of Bayesian neural networks with fuzzy logic inferences was applied to data from five trials of Tirilazad for aneurysmal subarachnoid hemorrhage (3551 patients). Results. Bayesianmeta-analyses of observational studies on aSAH prognostic factors gave generalizable posterior distributions of population mean log odd ratios (ORs). Similar trends were noted in Bayesian and linear regression ORs. Significant outcome predictors include normal motor response, cerebral infarction, history of myocardial infarction, cerebral edema, history of diabetes mellitus, fever on day 8, prior subarachnoid hemorrhage, admission angiographic vasospasm, neurological grade, intraventricular hemorrhage, ruptured aneurysm size, history of hypertension, vasospasm day, age and mean arterial pressure. Heteroscedasticity was present in the nontransformed dataset. Artificial neural networks found nonlinear relationships with 11 hidden variables in 1 layer, using the multilayer perceptron model. Fuzzy logic decision rules (centroid defuzzification technique) denoted cut-off points for poor prognosis at greater than 2.5 clusters. Discussion. This aSAH prognostic system makes use of existing knowledge, recognizes unknown areas, incorporates one's clinical reasoning, and compensates for uncertainty in prognostication. [ABSTRACT FROM AUTHOR]

The Dlx genes play an important role in the development of the pharyngeal arches and the structures derived from these tissues, including the craniofacial skeleton. They are typically expressed in a nested pattern along the proximo-distal axis of the branchial arches in mice. This pattern is known as the “Dlx code” and has been proposed to be responsible for an early regional patterning of branchial arches in mammals. A number of cis- regulatory elements (CREs) have been identified within the Dlx loci, which target reporter expression to the developing pharyngeal arches of the mouse. Most of these CREs are located in the intergenic regions between the two genes constituting a Dlx bigene cluster. Therefore, the regionalized dlx expression in the branchial arches could be the result of the shared activities of these regulatory regions. Here we analyze previously published and new results showing these CREs are highly conserved in both their sequence and their activity in the pharyngeal arches of two distantly related vertebrates, the zebrafish and the mouse. A better understanding of Dlx gene regulation of the Dlx genes and of the genetic cascades in which they are involved can lead to clues explaining variations in morphology of the craniofacial regions of vertebrates. [ABSTRACT FROM AUTHOR]

Fisheries enforcement is often tasked with determining whether a seized Pacific salmon Oncorhynchus spp. has been caught legally or illegally, either in freshwater while it was migrating to its natal stream or in the ocean at some point during its life cycle or migration. Here we show that the oxygen stable isotope composition (δ18O) of the water within seized fish tissue, together with DNA analysis, provides a powerful means of establishing where the fish was migrating and whether it was inhabiting freshwater when harvested. These tools ate relatively easy to apply and ate supported by an extensive set of microsatellite DNA data for sockeye salmon O. nerka that provide "forensic" identification and by a time series record for δ180 in the water of the Fraser River. The difference between δ18O composition in the river ∼-17%o) and the ocean ∼-2%o), together with conservative mixing between the end members, provides wide discriminatory power. Evaporation or sublimation during storage favors the light isotope and would thus be to the advantage of the defendant. [ABSTRACT FROM AUTHOR]

A water supply borehole in the Sherwood Sandstone aquifer in Warrington, UK was found to be infested with iron bacteria that resulted in large ochreous deposits and damaged the pump. Before the pump was replaced, the borehole was treated using hydrogen peroxide. Comparison of the borehole condition seen in CCTV surveys carried out before and after treatment shows that previously observed bacterial growths had been removed. A specific capacity curve was constructed from step test data and used to assess the borehole yield under operational conditions. This showed that the iron bacteria had increased drawdown by some 20% and that the treatment had restored the previous yield characteristics. The improvement is thought to be due to a mechanical scrubbing effect caused by the vigorous release of oxygen bubbles during the decay of the peroxide. [ABSTRACT FROM AUTHOR]

Single molecule detection based on fluorescent labels offers the possibility to gain not only qualitative but also quantitative insight into specific functions of complex biological systems. Fluorescence correlation spectroscopy is one of the favourite techniques to determine concentrations and diffusion constants as well as molecular brightness of molecules in the pico- to nano-molar concentration range, with broad applications in biology and chemistry. Although fluorescence correlation spectroscopy in principle has the potential to measure absolute concentrations and diffusion coefficients, the necessity to know the exact size and shape of the confocal volume very often hampers the possibility to obtain quantitative results and restricts fluorescence correlation spectroscopy to relative measurements mainly. The determination of the confocal volume in situ is difficult because it is sensitive to optical alignment and aberrations, optical saturation and variations of the index of refraction as observed in biological specimen. In the present contribution, we compare different techniques to characterize the confocal volume and to obtain the confocal parameters by fluorescence correlation spectroscopy curve fitting, a fluorescence correlation spectroscopy dilution series and confocal scanning of fluorescent beads. The results are compared in the view of quantitative fluorescence correlation spectroscopy measurement and analysis. We investigate how unavoidable artefacts caused by a non-ideal confocal volume can be experimentally determined and validated. [ABSTRACT FROM AUTHOR]

Electrophysiological and molecular characteristics of voltage-dependent calcium (Ca2+) channels were studied using whole-cell patch clamp, polymerase chain reaction and Western blotting in smooth muscle cells freshly isolated from dog basilar artery. Inward currents evoked by depolarizing steps from a holding potential of –50 or –90 mV in 10 mm barium consisted of low- (LVA) and high-voltage activated (HVA) components. LVA current comprised more than half of total current in 24 (12%) of 203 cells and less than 10% of total current in 52 (26%) cells. The remaining cells (127 cells, 62%) had LVA currents between one tenth and one half of total current. LVA current was rapidly inactivating, slowly deactivating, inhibited by high doses of nimodipine and mibefradil (> 0.3 μm), not affected by ω-agatoxin GVIA (γ100 nm), ω-conotoxin IVA (1 μm) or SNX-482 (200 nm) and probably carried by T-type Ca2+ channels based on the presence of messenger ribonucleic acid (mRNA) and protein for Cav3.1 and Cav3.3α1 subunits of these channels. LVA currents exhibited window current with a maximum of 13% of the LVA current at –37.4 mV. HVA current was slowly inactivating and rapidly deactivating. It was inhibited by nimodipine (IC50= 0.018 μm), mibefradil (IC50= 0.39 μm) and ω-conotoxin IV (1 μm). Smooth muscle cells also contained mRNA and protein for L- (Cav1.2 and Cav1.3), N- (Cav2.2) and T-type (Cav3.1 and Cav3.3) α1 Ca2+ channel subunits. Confocal microscopy showed Cav1.2 and Cav1.3 (L-type), Cav2.2 (N-type) and Cav3.1 and Cav3.3 (T-type) protein in smooth muscle cells. Relaxation of intact arteries under isometric tension in vitro to nimodipine (1 μm) and mibefradil (1 μm) but not to ω-agatoxin GVIA (100 nm), ω-conotoxin IVA (1 μm) or SNX-482 (1 μm) confirmed the functional significance of L- and T-type voltage-dependent Ca2+ channel subtypes but not N-type. These results show that dog basilar artery smooth muscle cells express functional voltage-dependent Ca2+ channels of multiple types. [ABSTRACT FROM AUTHOR]

Evidence-based medicine is an important way of allowing the reader to judge clearly whether a treatment has a place in a particular condition, and to see what faults were present in the various trials of its efficacy. It is often rather unsettling to read in a meta-analysis or in a systematic literature review how poorly constructed many trials are. The authors from Minneapolis have carried out such a study into the use of trazodone in male erectile dysfunction. They draw attention to the poor quality of many of the trials and give their reasons for this observation. They suggest that trazodone may be helpful in men with this condition, possibly at higher doses and in men with psychogenic erectile dysfunction. OBJECTIVE To determine the efficacy and safety of trazodone in the treatment of erectile dysfunction (ED) in a meta-analysis. METHODS The data sources used were Medline and the Cochrane Library databases (January 1966 to May 2002), bibliographies of retrieved articles and review articles, and conference proceedings and abstracts. Trials were eligible for inclusion in the review if they included men with ED, compared trazodone with a control, were randomized, of ≥ 7 days’ duration and assessed clinically relevant outcomes. Two reviewers independently evaluated study quality and extracted data in a standardized fashion. RESULTS Six trials (comprising 396 men) met the inclusion criteria; they consisted of heterogeneous populations, were small, brief and in some cases methodologically weak. Three of the six trials showed an apparently clinically meaningful benefit of trazodone for ED compared with placebo, the differences being statistically significant in two. In pooled results, trazodone monotherapy appeared more likely than placebo to lead to a ‘positive treatment response’, although this difference was not statistically significant (37% vs 20%; relative benefit increase, 1.6; 95% confidence interval, CI, 0.8–3.3). Subgroup analyses suggested that men with psychogenic ED might be more likely to benefit from trazodone than those with mixed or physiological ED. The efficacy of trazodone also appeared greater at higher doses (150–200 vs 50 mg/day). Men randomized to trazodone were not significantly more likely than those receiving placebo to withdraw for any reason or for an adverse event, or to have specific adverse events, but wide CIs could not exclude a greater risk of these adverse outcomes with trazodone. Specific adverse events with trazodone included dry mouth (19%), sedation (16%), dizziness (16%) and fatigue (15%). CONCLUSION Trazodone may be helpful in men with ED, possibly more so at higher doses, and in men with psychogenic ED. Future high-quality trials should compare trazodone with placebo and other therapies in men with depression and psychogenic ED. [ABSTRACT FROM AUTHOR]

In this paper we use the behavioural and permanent equilibrium exchange rate approaches to produce long–run equilibrium exchange rates for the effective real exchange rates of the New Zealand dollar. We demonstrate that a well founded measure of the equilibrium value of the dollar may be recovered from a relatively small set of fundamental variables and that this can be used to produce an assessment of the dollar in terms of periods of misalignment. [ABSTRACT FROM AUTHOR]

Objective To systematically review and evaluate the effectiveness and adverse effects of the α-antagonist, terazosin, for treating urinary symptoms associated with benign prostatic obstruction (BPO). Methods Studies were sought and included in the review if they were randomized trials of at least 1 month duration, involved men with symptomatic BPO and compared terazosin with placebo or active controls. The study, patient characteristics and outcome data were extracted in duplicate onto standardized forms using a prospectively developed protocol. Results Seventeen studies involving 5151 men met the inclusion criteria, i.e. placebo-controlled (10), α-blockers (seven), finasteride alone or combined with terazosin and placebo (one), and microwave therapy (one). The study duration was 4–52 weeks; the mean age of the men was 65 years and 82% were white. Baseline urological symptom scale scores and flow rates showed that men had moderate BPO. Efficacy outcomes were rarely reported in a way that allowed for data pooling, but indicated that terazosin improved symptom scores and flow rates more than did placebo or finasteride, and similarly to other α-antagonists. The pooled mean percentage improvement for the Boyarsky symptom score was 37% for terazosin and 15% for placebo (four studies). The mean percentage improvement for the American Urological Association symptom score was 38%, compared with 17% and 20% for placebo and finasteride, respectively (two studies). The pooled mean improvement in the International Prostate Symptom Score of 40% was similar to that with tamsulosin (43%). Peak urinary flow rates improved more with terazosin (22%) than with placebo (11%) and finasteride (15%), but did not differ significantly from the other α-antagonists. The percentage of men discontinuing terazosin was comparable with those receiving placebo and finasteride, but greater than with other α-antagonists. Adverse effects were greater than with... [ABSTRACT FROM AUTHOR]

The atomic force microscope was used to examine the cytoplasmic surface of untreated as well as fixed human erythrocyte membranes that had been continuously maintained under aqueous solutions. To assess the effects of drying, some membranes were examined in air. Erythrocytes attached to mica or glass were sheared open with a stream of isotonic buffer, which allowed access to the cytoplasmic membrane face without exposing cells to non-physiological ionic strength solutions. Under these conditions of examination, the unfixed cytoplasmic membrane face revealed an irregular meshwork that appeared to be a mixture largely of triangular and rectilinear openings with mesh sizes that varied from 35 to 100 nm, although few were at the upper limit. Fixed ghosts were similar, but slightly more contracted. These features represent the membrane skeleton, as when the ghosts were treated to extract spectrin and actin, these meshworks were largely removed. Direct measurements of the thickness of the membrane skeleton and of the lateral dimensions of features in the images suggested that, especially when air dried, spectrin can cluster into large, quite regularly distributed aggregates. Aggregation of cytoskeletal components was also favoured when the cells were attached to a polylysine-treated substrate. In contrast, the membrane skeletons of cells attached to substrates rendered positively charged by chemical derivatization with a cationic silane were much more resistant to aggregation. As steps were taken to reduce the possibility of change of the skeleton after opening the cells, the aggregates and voids were eliminated, and the observed structures became shorter and thinner. Ghosts treated with Triton X-100 solutions to remove the bilayer revealed a meshwork having aggregated components resembling those seen in air. These findings support the proposition that the end-to-end distance of spectrin tetramers in the cell in the equilibrium state is much shorter than the contour length of the molecule and that substantial rearrangements of the spectrin-actin network occur when it is expanded by low ionic strength extraction from the cell. This study demonstrates the applicability of AFM for imaging the erythrocyte membrane skeleton at a resolution that appears adequate to identify major components of the membrane skeleton under near-physiological conditions. [ABSTRACT FROM AUTHOR]

AbstractObjectiveTo investigate the use of transvaginal sonography in monitoring the cervix in women at high risk of a preterm delivery. Study designOne hundred and six women at high risk of preterm labor had regular cervical monitoring by transvaginal ultrasound throughout pregnancy from the second trimester to delivery. The study was designed to be observational, but intervention was considered if the cervical length fell below 10 mm. ResultsEleven women demonstrated opening of the cervical canal at rest or with fundal pressure before 24 weeks’ gestation. Between 2 and 17 days later all 11 cervices progressively shortened to a cervical length of < 10 mm. Nine women had a cervical cerclage. Seven women had fetal membranes visible within the cervical canal at the time of cerclage. One woman miscarried at 18 weeks, and the other 10 had live births at a median gestational age of 36 (range, 27–38) weeks. ConclusionsCervical length shortening in the second trimester, once started, progressed to a cervical length under 10 mm. Opening of the cervical os at rest or in response to fundal pressure detected by transvaginal ultrasound appears to be the early ultrasound feature of cervical incompetence. [ABSTRACT FROM AUTHOR]

A bipolar 1×16 amplifier array is described for hybrid integration with an 8×8 p-i-n photodiode array receiver and application for parallel data interconnects through optical fibre arrays or free-space imaging. Limiting amplifiers of the transimpedance–transadmittance type were designed for low power consumption in BiCMOS technology, and measured results for operation at 622 Mbits/s of the packaged amplifier–photodetector arrays are given. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 28: 11–15, 2001. [ABSTRACT FROM AUTHOR]

Objective To systematically review the evidence for the clinical effects and safety of the rye‐grass pollen extract (Cernilton) in men with symptomatic benign prostatic hyperplasia (BPH). Methods Trials were identified by searching Medline, specialized databases (EMBASE, Cochrane Library, Phytodok), bibliographies, and contacting relevant trialists and manufacturers. Randomized or controlled clinical trials were included if: men with symptomatic BPH were treated with Cernilton; a control group received either placebo or pharmacological therapy; the treatment duration was >= 30 days; and clinical outcomes were reported. Results In all, 444 men were enrolled in two placebo‐controlled and two comparative trials lasting 12–24 weeks. Three studies used a double‐blind method although the concealment of treatment allocation was unclear in all. Cernilton improved ‘self‐rated urinary symptoms’ (the proportion reporting satisfactory or improving symptoms) vs placebo and another plant product, Tadenan. The weighted mean (95% confidence interval) risk ratio (RR) for self‐rated improvement vs placebo was 2.40 (1.21–4.75) and the weighted RR vs Tadenan was 1.42 (1.21–4.75). Cernilton reduced nocturia compared with placebo or Paraprost (a mixture of amino acids); against placebo, the weighted RR was 2.05 (1.41–3.00), and against Paraprost the weighted mean difference for nocturia was – 0.40 times per evening (– 0.73 to 0.07). Cernilton did not improve urinary flow rates, residual volume or prostate size compared with placebo or the comparative study agents. Adverse events were rare and mild; the withdrawal rate for Cernilton was 4.8%, compared with 2.7% for placebo and 5.2% for Paraprost. Conclusions The Cernilton trials analysed were limited by their short duration, limited number of enrolees, omissions in reported outcomes, and the unknown quality of the preparations used. The comparative trials had no confirmed active control. The available evidence suggests that Cernilton is well tolerated and modestly improves overall urological symptoms, including nocturia. Additional randomized placebo and active‐controlled trials are needed to evaluate the long‐term clinical effectiveness and safety of Cernilton. [ABSTRACT FROM AUTHOR]

In glasshouse and laboratory experiments, calcium alginate gel, produced in situ on wounds by successive dipping in solutions of sodium alginate and CaCl2 gave significant protection against infection by pathogenic isolates of Agrobacterium tumefaciens on carrot discs, tomato cuttings and chrysanthemum cuttings. Gel protection was sometimes equal to that given by strain K84 of A. radiobacter and also operated a pathogenic isolate insensitive to control by strain K84. Sodium alginate or CaCl2 alone gave little or no protection, suggesting that calcium alginate acted by physically excluding the pathogen from wound surfaces. The use of the method described is discussed for delivery of biological or chemical control agents to plant surfaces whilst also providing protection in its own right. [ABSTRACT FROM AUTHOR]