bluuebunny/crossref_metadata_2025_split huggingface dataset:
Monte Carlo dosimetric characterization of the IsoAid ADVANTAGE brachytherapy source
Authors: Sowards Keith T. 
Published: February 2017

For roughly 25 years, and sources have been used in the treatment of various malignant diseases such as prostate cancer. Various new sources have been marketed and produced to meet the demand for new sources to use in treatment. Recently, IsoAID LLC created the ADVANTAGE source. Various dosimetric parameters must be determined to facilitate treatment planning using this source. Theoretical determination of dosimetric characteristics, dose rate constant, radial dose function, and anisotropy function for this new source followed the American Association of Physicists in Medicine (AAPM) Task Group 43U1 recommendations. Theoretical calculations were performed in liquid water using the PTRAN Monte Carlo code version 7.44. The radial dose function of the new source was calculated in liquid water at distances up to 10.0 cm, and the anisotropy function, at distances ranging from 0.5 cm to 7.0 cm. The anisotropy factors and anisotropy constant were derived from the anisotropy function. The results in water indicate that the dose rate constant is and that the anisotropy constant is . The dosimetric characteristics of this new source compare favorably with those of other commercially available sources.PACS: 87.53.Jw
Driver Movement Patterns Indicate Distraction and Engagement
Authors: Radwin Robert G. , Lee John D. , Akkas Oguz 
Published: February 2017

Objective This research considers how driver movements in video clips of naturalistic driving are related to observer subjective ratings of distraction and engagement behaviors. Background Naturalistic driving video provides a unique window into driver behavior unmatched by crash data, roadside observations, or driving simulator experiments. However, manually coding many thousands of hours of video is impractical. An objective method is needed to identify driver behaviors suggestive of distracted or disengaged driving for automated computer vision analysis to access this rich source of data. Method Visual analog scales ranging from 0 to 10 were created, and observers rated their perception of driver distraction and engagement behaviors from selected naturalistic driving videos. Driver kinematics time series were extracted from frame-by-frame coding of driver motions, including head rotation, head flexion/extension, and hands on/off the steering wheel. Results The ratings were consistent among participants. A statistical model predicting average ratings from the kinematic features accounted for 54% of distraction rating variance and 50% of engagement rating variance. Conclusion Rated distraction behavior was positively related to the magnitude of head rotation and fraction of time the hands were off the wheel. Rated engagement behavior was positively related to the variation of head rotation and negatively related to the fraction of time the hands were off the wheel. Application If automated computer vision can code simple kinematic features, such as driver head and hand movements, then large-volume naturalistic driving videos could be automatically analyzed to identify instances when drivers were distracted or disengaged.
The value of adding sub-valvular procedures for chronic ischemic mitral regurgitation surgery: a meta-analysis
Authors: Moscarelli Marco , Athanasiou Thanos , Speziale Giuseppe , Punjabi Prakash P. , Malietzis George , Lancellotti Patrizio , Fattouch Khalil 
Published: February 2017

Background: The most performed repair technique for the treatment of chronic ischemic mitral regurgitation in patients referred for bypass grafting remains restricted annuloplasty. However, it is associated with a high rate of failure, especially if severe tenting exists. Objectives: To understand if adjunctive sub-valvular mitral procedures may provide better repair performance. Methods: A systematic literature review identified six studies of which five fulfilled the criteria for meta-analysis. Outcomes for a total of 404 patients (214 had adjunctive sub-valvular procedures and 190 restricted annuloplasty) were meta-analyzed using random effects modeling. Heterogeneity and subgroup sensitivity analysis were assessed. Primary endpoints were: late recurrence of moderate mitral regurgitation, left ventricle remodeling and coaptation depth at follow-up. Secondary endpoints were: early mortality, mid-term survival and operative outcomes. Results: Sub-valvular procedure technique was associated with a significantly lower late recurrence of mitral regurgitation (Odds ratio (OR) 0.34, 95% Confidence Interval (CI) [0.18, 0.65], p=0.0009), smaller left ventricle end-systolic diameter (Weighted Mean Difference (WMD) -4.06, 95% CI [-6.10, -2.03], p=0.0001) and reduced coaptation depth (WMD -2.36, 95% CI [-5.01, -0.71], p=0.009). These findings were consistent, even in studies that included patients at high risk for repair failure (coaptation depth >10 mm and tenting area >2.5 cm2). A low degree of heterogeneity was observed. There was no difference in terms of early mortality and mid-term survival; sub-valvular technique was associated with prolonged cardiopulmonary and cross-clamp time. Conclusions: Adding sub-valvular procedures when repairing ischemic chronic mitral valve regurgitation may be associated with better durability, even in the case of the presence of predictors for late failure. Perspective: Surgical sub-valvular adjunctive procedures have to be considered in the case of the presence of echocardiographic predictors for late failure.
Early rehabilitation after hospital admission for road trauma using an in-reach multidisciplinary team: a randomised controlled trial
Authors: Wu Jane , Faux Steven G , Estell John , Wilson Stephen , Harris Ian , Poulos Christopher J , Klein Linda 
Published: February 2017

Objective: To investigate the impact of an in-reach rehabilitation team for patients admitted after road trauma. Design: Randomised control trial of usual care versus early involvement of in-reach rehabilitation team. Telephone follow-up was conducted by a blind assessor at three months for those with minor/moderate injuries and six months for serious/severe injuries. Setting: Four participating trauma services in New South Wales, Australia. Subjects: A total of 214 patients admitted during 2012-2015 with a length of stay of at least five days. Intervention: Provision of rehabilitation services in parallel with ward based therapy using an in-reach team for the intervention group. The control group could still access the ward based therapy (usual care). Main measures: The primary outcome was acute length of stay. Secondary outcomes included percentage requiring inpatient rehabilitation, function (Functional Independence Measure and Timed Up and Go Test), psychological status (Depression Anxiety and Stress Score 21), pain (Orebro Musculoskeletal Pain Questionnaire) and quality of life (Short Form-12 v2). Results: Median length of stay in acute care was 13 days (IQR 8-21). The intervention group, compared to the control group, received more physiotherapy and occupational therapy sessions (median number of sessions 16.0 versus 11.5, P=0.003). However, acute length of stay did not differ between the intervention and control groups (median 15 vs 12 days, P=0.37). There were no significant differences observed in the secondary outcomes at hospital discharge and follow-up. Conclusion: No additional benefit was found from the routine use of acute rehabilitation teams for trauma patients over and above usual care.
Parental experiences with a paediatric palliative care team: A qualitative study
Authors: Verberne Lisa M , Schouten-van Meeteren Antoinette YN , Bosman Diederik K , Colenbrander Derk A , Jagt Charissa T , Grootenhuis Martha A , van Delden Johannes JM , Kars Marijke C 
Published: February 2017

Background: Parents of children with a life-limiting disease have to rely on themselves at home while adequate paediatric palliative care is lacking. In several countries, paediatric palliative care teams are introduced to ensure continuity and quality of care and to support the child and the family. Yet, little is known about how parents experience such multidisciplinary teams. Aim: To obtain insight into the support provided by a new paediatric palliative care team from the parents’ perspective. Design: An interpretative qualitative interview study using thematic analysis was performed. Setting/participants: A total of 47 single or repeated interviews were undertaken with 42 parents of 24 children supported by a multidisciplinary paediatric palliative care team located at a university children’s hospital. The children suffered from malignant or non-malignant diseases. Results: In advance, parents had limited expectations of the paediatric palliative care team. Some had difficulty accepting the need for palliative care for their child. Once parents experienced what the team achieved for their child and family, they valued the team’s involvement. Valuable elements were as follows: (1) process-related aspects such as continuity, coordination of care, and providing one reliable point of contact; (2) practical support; and (3) the team members’ sensitive and reliable attitude. As a point of improvement, parents suggested more concrete clarification upfront of the content of the team’s support. Conclusion: Parents feel supported by the paediatric palliative care team. The three elements valued by parents probably form the structure that underlies quality of paediatric palliative care. New teams should cover these three valuable elements.
Histogram analysis of volume-based apparent diffusion coefficient in breast cancer
Authors: Park Ga Eun , Kim Sung Hun , Kim Eun Jeong , Kang Bong Joo , Park Mi Sun 
Published: February 2017

Background Breast cancer is a heterogeneous disease. Recent studies showed that apparent diffusion coefficient (ADC) values have various association with tumor aggressiveness and prognosis. Purpose To evaluate the value of histogram analysis of ADC values obtained from the whole tumor volume in invasive ductal cancer (IDC) and ductal carcinoma in situ (DCIS). Material and Methods This retrospective study included 201 patients with confirmed DCIS (n = 37) and IDC (n = 164). The IDC group was divided into two groups based on the presence of a DCIS component: IDC–DCIS (n = 76) and pure IDC (n = 88). All patients underwent preoperative breast magnetic resonance imaging (MRI) with diffusion-weighted images at 3.0 T. Histogram parameters of cumulative ADC values, skewness, and kurtosis were calculated and statistically analyzed. Results The differences between DCIS, IDC–DCIS, and pure IDC were significant in all percentiles of ADC values, in descending order of DCIS, IDC–DCIS, and pure IDC. IDC showed significantly lower ADC values than DCIS, and ADC50 was the best indicator for discriminating IDC from DCIS, with a threshold of 1.185 × 10–3 mm2/s (sensitivity of 82.9%, specificity of 75.7%). However, multivariate analysis of obtained ADC values showed no significant differences between DCIS, IDC–DCIS, and pure IDC ( P > 0.05). Conclusion Volume-based ADC values showed association with heterogeneity of breast cancer. However, there was no additional diagnostic performance in histogram analysis for differentiating between DCIS, IDC–DCIS, and pure IDC.
Background echotexture classification in breast ultrasound: inter-observer agreement study
Authors: Kim Won Hwa , Lee Su Hyun , Chang Jung Min , Cho Nariya , Moon Woo Kyung 
Published: February 2017

Background According to the American College of Radiology (ACR) Breast Imaging Reporting and Data System (BI-RADS), background echotexture in breast ultrasound (US) can be categorized as homogeneous or heterogeneous. Purpose To prospectively evaluate the inter-observer agreement of a four-category classification in background echotexture assessments of breast US and to determine whether background echotexture is related to breast cancer risk factors, including mammography density. Material and Methods Thirty-eight healthy women (age range, 25–72) were recruited. Eleven radiologists performed breast US on all participants and classified each background echotexture into four categories (homogeneous, mild, moderate, and marked heterogeneous). The inter-observer agreement in the assessments was measured using kappa statistics (к). The association between background echotexture and breast cancer risk factors, including mammographic density, menopausal status, and parity, were evaluated using Spearman’s correlation coefficient (ρ) and multiple linear regression analysis. Results There was moderate inter-observer agreement between the radiologists for the four categories of background echotexture (average к = 0.45). Heterogeneity of the background echotexture was positively correlated with mammographic density in both pre- and postmenopausal women (premenopausal, ρ = 0.42, P < 0.0001; postmenopausal, ρ = 0.56, P < 0.0001). Multiple linear regression analysis revealed that mammographic density and parity were significantly associated with background echotexture. Conclusion Background echotexture assessment of breast US using a four-category classification showed moderate inter-observer agreement, and more heterogeneous background echotexture was associated with denser breasts and lower parity.
Outcomes After Biologically Augmented Isolated Meniscal Repair With Marrow Venting Are Comparable With Those After Meniscal Repair With Concomitant Anterior Cruciate Ligament Reconstruction
Authors: Dean Chase S. , Chahla Jorge , Matheny Lauren M. , Mitchell Justin J. , LaPrade Robert F. 
Published: February 2017

Background: Meniscal repair in the setting of anterior cruciate ligament (ACL) reconstruction has demonstrated superior outcomes compared with isolated meniscal repair. Limited evidence exists for the effects of biological augmentation in isolated meniscal repair, particularly as compared with meniscal repair with concomitant ACL reconstruction. Purpose/Hypothesis: The purpose of this study was to compare the outcomes and survivorship of meniscal repair in 2 cohorts of patients: meniscal repair with biological augmentation using a marrow venting procedure (MVP) of the intercondylar notch, and meniscal repair with concomitant ACL reconstruction. We hypothesized that the clinical outcomes and survivorship of meniscal repair with concomitant ACL reconstruction would be improved compared with meniscal repair with biological augmentation. Study Design: Cohort study; Level of evidence, 3. Methods: Inclusion criteria were skeletally mature patients aged ≥16 years who underwent inside-out meniscal repair and either a concomitant MVP of the intercondylar notch or ACL reconstruction. Patients were excluded from this study if they were skeletally immature, underwent meniscus root or radial tear repair, or underwent meniscal repair with concurrent ligamentous reconstruction not limited to the ACL. At the preoperative evaluation and a minimum 2 years after the index meniscal repair procedure, patients were administered a subjective questionnaire. Differences in outcome scores, survivorship, and failure rates between the cohorts were assessed. Failure was defined as reoperation with meniscectomy or revision meniscal repair. Results: There were 109 patients (52 female, 57 male) who met the inclusion criteria for this study. There were 37 knees in cohort 1 (isolated meniscal repair plus MVP) and 72 knees in cohort 2 (meniscal repair plus ACL reconstruction). The failure status was known in 95 patients, and patient-reported outcome scores were obtained in 89 (82%) patients. Both cohorts demonstrated a significant improvement in all outcome scores, and there was no significant difference in any of the preoperative or postoperative outcome measures. The overall failure rate was 9.5% (9/95). There were 4 (12.9%) failures in cohort 1 and 5 failures (7.8%) in cohort 2, with no significant difference in failures between the cohorts ( P = .429). There was a significant association between failure and female sex ( P = .001). Conclusion: The most important finding in this study was that there was no difference in outcomes in meniscal repair performed with biological augmentation using an MVP versus that performed concomitantly with ACL reconstruction. The similar outcomes reported for meniscal repair with an MVP and meniscal repair with ACL reconstruction may be partly attributed to biological augmentation.
Defining the “Substantial Clinical Benefit” After Arthroscopic Treatment of Femoroacetabular Impingement
Authors: Nwachukwu Benedict U. , Chang Brenda , Fields Kara , Rebolledo Brian J. , Nawabi Danyal H. , Kelly Bryan T. , Ranawat Anil S. 
Published: February 2017

Background: The minimal clinically important difference (MCID) has been defined in orthopaedics and is the smallest change that a patient considers meaningful. Less is known about improvements that the patient perceives as clinically considerable, or the substantial clinical benefit (SCB). For the young, highly functioning patient cohort with femoroacetabular impingement (FAI), the SCB is an important measure of clinical success. Purpose: To derive the SCB for FAI treatment and identify outcome score thresholds and patient variables predictive of the SCB. Study Design: Cohort study (diagnosis); Level of evidence, 2. Methods: The modified Harris Hip Score (mHHS), the Hip Outcome Score activities of daily living (HOS-ADL) and sport (HOS-Sport) subscales, and the international Hip Outcome Tool (iHOT-33) were prospectively administered to 364 patients with a minimum 1-year follow-up. At 1 year postoperatively, patients graded their hip function based on several anchor responses such as “no change” and “much improved.” The SCB was defined as the change on each outcome tool that equated to the difference between “no change” and “much improved” on the health transition question. Receiver operating characteristic analysis with area under the curve (AUC) was used to identify optimal values that were most representative of the SCB. Multivariable analysis identified patient variables predictive of the SCB. Results: The net change in outcome scores corresponding to the SCB for the mHHS, HOS-ADL, HOS-Sport, and iHOT-33 was 19.8, 10.0, 29.9, and 24.5, respectively. The following postoperative outcome scores demonstrated excellent distinction (AUC >0.8) between “no change” and “much improved” and thus were considered absolute values for the postoperative SCB: 82.5 (mHHS), 93.3 (HOS-ADL), 84.4 (HOS-Sport), and 63.5 (iHOT-33). Preoperative scores on the HOS-ADL (83.3) and HOS-Sport (50.0) were significant threshold cutoffs, above which attaining the SCB became less likely. Younger age and lower Outerbridge grade were predictive of achieving the SCB. Conclusion: The SCB has not been previously defined in the hip preservation literature and is complementary to the MCID as the upper bound for clinically significant improvement. We identified predictive preoperative and diagnostic postoperative outcome scores for the SCB that can be used to manage patient expectations and grade outcomes. These findings are objective criteria for defining clinical success after arthroscopic FAI treatment.
Clinico-pathological features of repeat renal biopsies in patients with lupus nephritis at Groote Schuur Hospital, Cape Town
Authors: Kajawo S , Botha F C J , Okpechi I G 
Published: February 2017

Background Repeat renal biopsies in patients with lupus nephritis are usually done to guide treatment or to establish disease chronicity. Their value is not clear from available literature. There are also no available data in Africa to guide clinicians. Methods This was a retrospective study of patients undergoing a repeat renal biopsy between January 2003 and December 2014 from a single centre in Cape Town, South Africa. Relevant demographic, clinical and histological records of patients with repeat renal biopsies were documented. Comparison of data from first and second renal biopsy was performed. Results Forty-four patients had at least two biopsies done during the study period. Most patients were females (81.8%). The mean biopsy interval was 2.8 ± 1.8 (range 0.38–9.4) years. Proteinuria was the main indication for the repeat biopsy (36.1%). The glomerular filtration rate and proteinuria worsened between the two biopsies ( p = 0.001 and 0.019, respectively) suggesting disease progression. Most patients (65.4%) with a non-proliferative class of lupus nephritis at first biopsy progressed into a proliferative class, whereas patients with initial proliferative lupus nephritis at first biopsy (77.8%) remained as proliferative at repeat biopsy. Treatment was changed in 85% of patients at second biopsy. Conclusion Repeat renal biopsies in patients with lupus nephritis presents a useful means of assessing disease progression and provides guidance regarding modification of treatment. More studies are, however, required to evaluate the value of repeat biopsies and perhaps the need for protocol renal biopsies in patients with lupus nephritis.
Quantitative imaging biomarkers: Effect of sample size and bias on confidence interval coverage
Authors: Obuchowski Nancy A , Bullen Jennifer 
Published: February 2017

Introduction Quantitative imaging biomarkers (QIBs) are being increasingly used in medical practice and clinical trials. An essential first step in the adoption of a quantitative imaging biomarker is the characterization of its technical performance, i.e. precision and bias, through one or more performance studies. Then, given the technical performance, a confidence interval for a new patient’s true biomarker value can be constructed. Estimating bias and precision can be problematic because rarely are both estimated in the same study, precision studies are usually quite small, and bias cannot be measured when there is no reference standard. Methods A Monte Carlo simulation study was conducted to assess factors affecting nominal coverage of confidence intervals for a new patient’s quantitative imaging biomarker measurement and for change in the quantitative imaging biomarker over time. Factors considered include sample size for estimating bias and precision, effect of fixed and non-proportional bias, clustered data, and absence of a reference standard. Results Technical performance studies of a quantitative imaging biomarker should include at least 35 test–retest subjects to estimate precision and 65 cases to estimate bias. Confidence intervals for a new patient’s quantitative imaging biomarker measurement constructed under the no-bias assumption provide nominal coverage as long as the fixed bias is <12%. For confidence intervals of the true change over time, linearity must hold and the slope of the regression of the measurements vs. true values should be between 0.95 and 1.05. The regression slope can be assessed adequately as long as fixed multiples of the measurand can be generated. Even small non-proportional bias greatly reduces confidence interval coverage. Multiple lesions in the same subject can be treated as independent when estimating precision. Conclusion Technical performance studies of quantitative imaging biomarkers require moderate sample sizes in order to provide robust estimates of bias and precision for constructing confidence intervals for new patients. Assumptions of linearity and non-proportional bias should be assessed thoroughly.