bluuebunny/crossref_metadata_2025_split huggingface dataset:
Sci‐Fri AM: Quality, Safety, and Professional Issues 01: CPQR Technical Quality Control Suite Development including Quality Control Workload Results
Authors: Malkoske Kyle , Nielsen Michelle , Brown Erika , Diamond Kevin , Frenière Normand , Grant John , Pomerleau‐Dalcourt Natalie , Schella Jason , Schreiner L. John , Tantot Laurent , Barajas Eduardo Villareal , Bissonnette Jean‐Pierre 
Published: August 2016

A close partnership between the Canadian Partnership for Quality Radiotherapy (CPQR) and the Canadian Organization of Medical Physicist's (COMP) Quality Assurance and Radiation Safety Advisory Committee (QARSAC) has resulted in the development of a suite of Technical Quality Control (TQC) Guidelines for radiation treatment equipment, that outline specific performance objectives and criteria that equipment should meet in order to assure an acceptable level of radiation treatment quality.The framework includes consolidation of existing guidelines and/or literature by expert reviewers, structured stages of public review, external field‐testing and ratification by COMP. The adopted framework for the development and maintenance of the TQCs ensures the guidelines incorporate input from the medical physics community during development, measures the workload required to perform the QC tests outlined in each TQC, and remain relevant (i.e. “living documents”) through subsequent planned reviews and updates. This presentation will show the Multi‐Leaf Linear Accelerator document as an example of how feedback and cross‐national work to achieve a robust guidance document.During field‐testing, each technology was tested at multiple centres in a variety of clinic environments. As part of the defined feedback, workload data was captured. This lead to average time associated with testing as defined in each TQC document. As a result, for a medium‐sized centre comprising 6 linear accelerators and a comprehensive brachytherapy program, we evaluate the physics workload to 1.5 full‐time equivalent physicist per year to complete all QC tests listed in this suite.
Sci‐Fri AM: Quality, Safety, and Professional Issues 04: Predicting waiting times in Radiation Oncology using machine learning
Authors: Joseph Ackeem , Herrera David , Hijal Tarek , Hendren Laurie , Leung Alvin , Wainberg Justin , Sawaf Marya , Maxim Gorshkov , Maglieri Robert , Keshavarz Mehryar , Kildea John 
Published: August 2016

We describe a method for predicting waiting times in radiation oncology. Machine learning is a powerful predictive modelling tool that benefits from large, potentially complex, datasets. The essence of machine learning is to predict future outcomes by learning from previous experience. The patient waiting experience remains one of the most vexing challenges facing healthcare. Waiting time uncertainty can cause patients, who are already sick and in pain, to worry about when they will receive the care they need. In radiation oncology, patients typically experience three types of waiting:

Waiting at home for their treatment plan to be prepared
Waiting in the waiting room for daily radiotherapy
Waiting in the waiting room to see a physician in consultation or follow‐upThese waiting periods are difficult for staff to predict and only rough estimates are typically provided, based on personal experience. In the present era of electronic health records, waiting times need not be so uncertain. At our centre, we have incorporated the electronic treatment records of all previously‐treated patients into our machine learning model. We found that the Random Forest Regression model provides the best predictions for daily radiotherapy treatment waiting times (type 2). Using this model, we achieved a median residual (actual minus predicted value) of 0.25 minutes and a standard deviation residual of 6.5 minutes. The main features that generated the best fit model (from most to least significant) are: Allocated time, median past duration, fraction number and the number of treatment fields.
Sci‐Fri AM: Quality, Safety, and Professional Issues 05: QC Program Management and the Benefits of QATrack+
Authors: Angers Crystal Plume , Bottema Ryan , Buckley Lesley , Studinski Ryan 
Published: August 2016

Purpose:Treatment unit uptime statistics are typically used to monitor radiation equipment performance. The Ottawa Hospital Cancer Centre has introduced the use of Quality Control (QC) test success as a quality indicator for equipment performance and overall health of the equipment QC program.Methods:Implemented in 2012, QATrack+ is used to record and monitor over 1100 routine machine QC tests each month for 20 treatment and imaging units (http://qatrackplus.com/). Using an SQL (structured query language) script, automated queries of the QATrack+ database are used to generate program metrics such as the number of QC tests executed and the percentage of tests passing, at tolerance or at action. These metrics are compared against machine uptime statistics already reported within the program.Results:Program metrics for 2015 show good correlation between pass rate of QC tests and uptime for a given machine. For the nine conventional linacs, the QC test success rate was consistently greater than 97%. The corresponding uptimes for these units are better than 98%. Machines that consistently show higher failure or tolerance rates in the QC tests have lower uptimes. This points to either poor machine performance requiring corrective action or to problems with the QC program.Conclusions:QATrack+ significantly improves the organization of QC data but can also aid in overall equipment management. Complimenting machine uptime statistics with QC test metrics provides a more complete picture of overall machine performance and can be used to identify areas of improvement in the machine service and QC programs.
Sci‐Fri PM: Radiation Therapy, Planning, Imaging, and Special Techniques ‐ 05: A novel respiratory motion simulation program for VMAT treatment plans: a phantom validation study
Authors: Hubley Emily , Pierce Greg , Ploquin Nicolas 
Published: August 2016

Purpose:To develop and validate a computational method to simulate craniocaudal respiratory motion in a VMAT treatment plan.Methods:Three 4DCTs of the QUASAR respiratory motion phantom were acquired with a 2cm water‐density spherical tumour embedded in cedar to simulate lung. The phantom was oscillating sinusoidally with an amplitude of 2cm and periods of 3, 4, and 5 seconds. An ITV was contoured and 5mm PTV margin was added. High and a low modulation factor VMAT plans were created for each scan. An in‐house program was developed to simulate respiratory motion in the treatment plans by shifting the MLC leaf positions relative to the phantom. Each plan was delivered to the phantom and the dose was measured using Gafchromic film. The measured and calculated plans were compared using an absolute dose gamma analysis (3%/3mm).Results:The average gamma pass rate for the low modulation plan and high modulation plans were 91.1% and 51.4% respectively. The difference between the high and low modulation plans gamma pass rates is likely related to the different sampling frequency of the respiratory curve and the higher MLC leaf speeds in the high modulation plan. A high modulation plan has a slower gantry speed and therefore samples the breathing cycle at a coarser frequency leading to inaccuracies between the measured and planned doses.Conclusion:A simple program, including a novel method for increasing sampling frequency beyond the control point frequency, has been developed to simulate respiratory motion in VMAT plans by shifting the MLC leaf positions.
Sci‐Fri PM: Radiation Therapy, Planning, Imaging, and Special Techniques ‐ 07: Transitioning from extended‐distance total body irradiation to optimized VMAT total marrow irradiation
Authors: Cherpak Amanda , Chytyk‐Praznik Krista , Yewondwossen Mammo , Schella Jason , Davis Carol‐Anne , Day Allan , DeGiobbi Jennifer , McAloney Dave , Mulroy Liam 
Published: August 2016

Purpose:TMI targets only the bone marrow, with the intent of sparing normal tissues. The NSCC has recently implemented a TMI protocol which includes VMAT fields to treat the bone marrow from head to mid‐thigh and extended SSD POP fields to treat the lower legs. This work describes the commissioning and initial clinical results of the first reported VMAT TMI treatments in Canada.Methods:Detailed CT simulation, imaging, planning and treatment procedures were developed by a multi‐disciplinary team. Patients have 1 cm of bolus over the lower legs and 0.5 cm of bolus around the lower arms. The PTV includes all bone, except mandible, facial bones and hands, with the objective of V(12 Gy) > 90%. Detailed analysis of the influence of field overlap was performed to determine optimal field placement and image‐guidance tolerances.Results:PTV coverage was achieved for all cases as V(12 Gy) ranged from 90.4–96.3%. The minimum dose to the PTV, D(99%), ranged from 91.4–97.87% and V(90%Rx=10.8 Gy) ranged from 99.1–100.0%. The lungs, liver and heart had an average Dmean of (7.8±0.3)Gy/(65±2)%, (7.6±0.7)Gy/(63±5)%, and (6.8±0.4)Gy/(56±4)% respectively.Conclusions:Commissioning required input and collaboration from all team members. Transitioning from TBI to TMI requires additional time for contouring, treatment planning, QA, and treatment. Patient benefit can however be seen in the quality of OAR sparing.
Sci‐Fri PM: Radiation Therapy, Planning, Imaging, and Special Techniques ‐ 10: Results from Canada Wide Survey on Total Body Irradiation Practice
Authors: Studinski Ryan , Fraser Danielle , Samant Rajiv , MacPherson Miller 
Published: August 2016

Purpose:Total Body Irradiation (TBI) is delivered to a relatively small number of patients with a variety of techniques; it has been a challenge to develop consensus studies for best practice. This survey was created to assess the current state of TBI in Canada.Methods:The survey was created with questions focusing on the radiation prescription, delivery technique and resources involved. The survey was circulated electronically to the heads of every clinical medical physics department in Canada. Responses were gathered and collated, and centres that were known to deliver TBI were urged to respond.Results:Responses from 20 centres were received, including 12 from centres that perform TBI. Although a variety of TBI dose prescriptions were reported, 12 Gy in 6 fractions was used in 11 centres while 5 centres use unique prescriptions. For dose rate, a range of 9 to 51 cGy/min was reported.Most centres use an extended SSD technique, with the patient standing or lying down against a wall. The rest use either a “sweeping” technique or a more complicated multi‐field technique. All centres but one indicated that they shield the lungs, and only a minority shield other organs.The survey also showed that considerable resources are used for TBI including extra staffing, extended planning and treatment times and the use of locally developed hardware or software.Conclusions:This survey highlights that both similarities and important discrepancies exist between TBI techniques across the country, and is an opportunity to prompt more collaboration between centres.
Sci‐Sat AM: Radiation Dosimetry and Practical Therapy Solutions ‐ 03: Energy dependence of a clinical probe‐format calorimeter and its pertinence to absolute photon and electron beam dosimetry
Authors: Renaud James , Seuntjens Jan , Sarfehnia Arman 
Published: August 2016

Purpose:To evaluate the intrinsic and absorbed‐dose energy dependence of a small‐scale graphite calorimeter probe (GPC) developed for use as a routine clinical dosimeter. The influence of charge deposition on the response of the GPC was also assessed by performing absolute dosimetry in clinical linac‐based electron beams.Methods:Intrinsic energy dependence was determined by performing constant‐temperature calorimetry dose measurements in a water‐equivalent solid phantom, under otherwise reference conditions, in five high‐energy photon (63.5 < %dd(10)X < 76.3), and five electron (2.3 cm < R50 < 8.3 cm) beams. Reference dosimetry was performed for all beams in question using an Exradin A19 ion chamber with a calibration traceable to national standards. The absorbed‐dose component of the overall energy dependence was calculated using the EGSnrc egs_chamber user code.Results:A total of 72 measurements were performed with the GPC, resulting in a standard error on the mean absorbed dose of better than 0.3 % for all ten beams. For both the photon and electron beams, no statistically‐significant energy dependence was observed experimentally. Peak‐to‐peak, variations in the relative response of the GPC across all beam qualities of a given radiation type were on the order of 1 %. No effects, either transient or permanent, were attributable to the charge deposited by the electron beams.Conclusions:The GPC's apparent energy‐independence, combined with its well‐established linearity and dose rate independence, make it a potentially useful dosimetry system capable measuring photon and electron doses in absolute terms at the clinical level.
Sci‐Sat AM: Radiation Dosimetry and Practical Therapy Solutions ‐ 06: Investigation of an absorbed dose to water formalism for a miniature low‐energy x‐ray source
Authors: Watson Peter , Seuntjens Jan 
Published: August 2016

Purpose:We present a formalism for calculating the absorbed dose to water from a miniature x‐ray source (The INTRABEAM system, Carl Zeiss), using a parallel‐plate ionization chamber calibrated in terms of air‐kerma. Monte Carlo calculations were performed to derive a chamber conversion factor (CQ) from reference air‐kerma to dose to water for the INTRABEAM. CQ was investigated as a function of depth in water, and compared with the manufacturer's reported value. The effect of chamber air cavity dimension tolerance was also investigated.Methods:Air‐kerma (Ak) from a reference beam was calculated using the EGSnrc user code cavity. Using egs_chamber, a model of a PTW 34013 parallel‐plate ionization chamber was created according to manufacturer specifications. The dose to the chamber air cavity (Dgas) was simulated both in‐air (with reference beam) and in‐water (with INTRABEAM source). Dose to a small water voxel (Dw) was also calculated. CQ was derived from these quantities.Results:CQ was found to vary by up to 15% (1.30 vs 1.11) between chamber dimension extremes. The agreement between chamber CQ was found to improve with increasing depth in water. However, in all cases investigated, CQ was larger than the manufacturer reported value of 1.054.Conclusions:Our results show that cavity dimension tolerance has a significant effect on CQ, with differences as large as 15%. In all cases considered, CQ was found to be larger than the reported value of 1.054. This suggests that the recommended calculation underestimates the dose to water.
Sci‐Sat AM: Radiation Dosimetry and Practical Therapy Solutions ‐ 08: A Low‐Cost Optical Scanner and Gantry for use with 3D Printing of Radiation Therapy Accessories
Authors: Rickey Daniel , Sasaki David , Dubey Arbind , Harris Chad , Johnson Kate , Egtberts Andy , Koul Rashmi 
Published: August 2016

Purpose:Three‐dimensional printing has been implemented at our institution to create customized treatment accessories including shielding and bolus. In order to effectively use 3D printing, the topography of the patient must first be acquired. To this end, we have evaluated a low‐cost structured‐light 3D scanner in order to assess the clinical viability of this technology.Methods:For ease of use, the scanner (3D Systems, Sense 3D Scanner) was mounted in a simple gantry that guided its motion and maintained an optimum distance between the scanner and the object. To characterise the spatial accuracy of the scanner, we used a geometric phantom and an anthropomorphic head phantom. The geometric phantom was machined from plastic and had overall dimensions of 24 cm by 15 cm and included a hemispherical and a tetrahedron protrusion roughly the dimensions of an average forehead and nose respectively. Meshes acquired by the optical scanner were compared to meshes generated from high‐resolution CT images.Results:Scans were acquired in under one minute. Most of the optical scans contained noticeable artefacts although in most instances these were considered minor. Using an algorithm that calculated distances between the two meshes, we found most of the optical scanner measurements agreed with those from CT to within about 1 mm for the geometric phantom and to within about 2 mm for the head phantom.Conclusion:In summary, we deemed this scanner to be clinically acceptable and it has been used to design treatment accessories for several skin cancer patients.
Sci‐Sat AM: Radiation Dosimetry and Practical Therapy Solutions ‐ 10: Towards LET detection: A study on the effects of scintillator doping
Authors: Nusrat Humza , Pang Geordi , Ahmad Syed , Keller Brian , Sarfehnia Arman 
Published: August 2016

Purpose:In radiotherapy, the amount of radiation delivered is determined by optimizing the amount of absorbed dose to the tumor. Dose does not always correlate well with the actual biological effects of radiation. This work seeks to validate the LET‐dependence of doped plastic scintillators for use in a radiation beam quality (LET) detector.Methods:The LET spectrum ([Φ]) can be resolved knowing the measured signals of uniquely LET‐dependent detectors, [S], and the response of each LET‐dependent detector to specific LETs ([R]), through the relation [Φ]=[S][R]−1. Plastic scintillator response is intrinsically LET dependent and can be varied via doping. Initial prototype consists of plastic scintillator and glass taper coupled to an optical fiber; components are housed in black acrylic, reducing effect of ambient light. In order to determine [R], the light response matrix, GEANT4.10.1 Monte Carlo (MC) was used. To validate MC, measurements were done using high energy electrons (9,12,15MeV) and orthovoltage x‐rays (100,250kV); scintillator signal was normalized to dose measured simultaneously.Results:Stopping power was varied by changing particle type/energy; measurements indicated that as stopping power increased from 1.9 to 6.6MeV/cm, detector response increased by 263% (+/−29.2%) for 5%Pb‐doped scintillator (155% in MC); 52% (+/−7.8%) increase observed when undoped scintillator was used (49% in MC). 5%Pb‐doped discrepancy (100kV x‐rays) is being investigated.Conclusions:This work validates that doping effects LET/energy response of scintillators; an effect that can be utilized for construction of an LET detector.
Relationships Among Middle School Students’ Expectancy Beliefs, Task Values, and Health-Related Fitness Performance
Authors: Chen Han , Sun Haichun , Dai Jun , Griffin Michael 
Published: August 2016

Purpose:The purpose of the study was to identify gender and body weight differences in Chinese adolescents’ perceived expectancy value (EV) motivation in their physical education (PE) class. The study also explored the relationship between EV and adolescents’ health-related fitness performances.Method:A group of seventh and eighth graders (N = 224) from China were measured on EV toward PE as well as health-related fitness levels. A two-way MANOVA test was used to examine gender and body weight differences in EV motivations. Several two-step hierarchical multiple regression analyses were conducted to examine the relationship between EV motivation and various fitness performances while controlling for the effects of gender and body weight.Results:Boys had higher expectancy beliefs and perceived their PE class as more interesting, useful, and important than girls did. Compared with overweight/obese students, students in the healthy weight group reported higher expectancy beliefs. When the effects of gender and body weight were accounted for, expectancy beliefs were the only reliable predictor influencing adolescents’ cardiorespiratory as well as muscular strength/endurance fitness levels.Discussion/Conclusion:Physical educators should use various teaching strategies to enhance students’ expectancy beliefs and task values. This is especially important for female students and overweight/obese students.
Multicenter Evaluation of BD Max Enteric Parasite Real-Time PCR Assay for Detection of Giardia duodenalis, Cryptosporidium hominis, Cryptosporidium parvum, and Entamoeba histolytica
Authors: Madison-Antenucci S. , Relich R. F. , Doyle L. , Espina N. , Fuller D. , Karchmer T. , Lainesse A. , Mortensen J. E. , Pancholi P. , Veros W. , Harrington S. M. 
Published: August 2016

ABSTRACT

Common causes of chronic diarrhea among travelers worldwide include protozoan parasites. The majority of parasitic infections are caused by
Giardia duodenalis
,
Entamoeba histolytica
,
Cryptosporidium parvum
, and
Cryptosporidium hominis
. Similarly, these species cause the majority of parasitic diarrhea acquired in the United States. Detection of parasites by gold standard microscopic methods is time-consuming and requires considerable expertise; enzyme immunoassays and direct fluorescent-antibody (DFA) stains have lowered hands-on time for testing, but improvements in sensitivity and technical time may be possible with a PCR assay. We performed a clinical evaluation of a multiplex PCR panel, the enteric parasite panel (EPP), for the detection of these common parasites using the BD Max instrument, which performs automated extraction and amplification. A total of 2,495 compliant specimens were enrolled, including 2,104 (84%) specimens collected prospectively and 391 (16%) specimens collected retrospectively. Approximately equal numbers were received in 10% formalin (1,273 specimens) and unpreserved (1,222 specimens). The results from the EPP were compared to those from alternate PCR and bidirectional sequencing (APCR), as well as DFA (
G. duodenalis
and
C. parvum
or
C. hominis
) or trichrome stain (
E. histolytica
). The sensitivity and specificity for prospective and retrospective specimens combined were 98.2% and 99.5% for
G. duodenalis
, 95.5% and 99.6 for
C. parvum
or
C. hominis
, and 100% and 100% for
E. histolytica
, respectively. The performance of the FDA-approved BD Max EPP compared well to the reference methods and may be an appropriate substitute for microscopic examination or immunoassays.
Commentary: The Confounding Role of Antimicrobial Stewardship Programs in Understanding the Impact of Technology on Patient Care
Authors: Doern Christopher D. 
Published: August 2016

ABSTRACT

Numerous studies have demonstrated the benefit of the combination of antimicrobial stewardship program (ASP) intervention and rapid diagnostic testing (RDT). However, few studies have attempted to study the incremental benefit of ASP and RDT, making it difficult to understand the true benefits of each intervention. This issue is discussed in the context of an article by S. H. McVane and F. S. Nolte (J Clin Microbiol 54:2476–2484, 2016,
http://dx.doi.org/doi:10.1128/JCM.00996-16
), with suggestions about how the findings of this study can be applied to other areas of clinical microbiology.