Lumbar Spine Injury in Indian Fast Bowlers: 3D Biomechanical Analysis and Prevention Strategies.

Background: Lumbar spine injuries are among the most common overuse injuries in a fast bowler. Among various causative factors, bowling action technique is a crucial one. Three-dimensional motion analysis has been accepted as a gold standard tool to identify incorrect techniques. Previous studies have identified key biomechanical variables associated with lumbar injury risk in fast bowlers. Despite the large popularity of the sport, there is limited information available on the subject in Indian fast bowlers. This study aims to analyse the lumbar spine injury risk in Indian fast bowlers with respect to key biomechanical variables, using 3D motion analysis. Methods: Forty-seven male first class fast bowlers underwent 3D motion analysis in an indoor biomechanics laboratory. Motion capture was done with 3D cameras and 2D video cameras, using a standard marker set. Data processing and analysis was done using proprietary software. Biomechanical variables associated with lumbar spine injury risk including lateral trunk flexion (LTF) and knee angle at front foot contact (KA at FFC) were measured, and peak vertical ground reaction forces (pVGRF) were simultaneously recorded using force plates. Descriptive analysis of the data was done. Results: 26% of bowlers had a high LTF, 29% had low KA at FFC and 43% had high pVGRF. Thus, a large proportion of bowlers in this study were at risk of lumbar spine injury with respect to the assessed variables. Conclusion: This highlights the role of 3D motion analysis in early identification of injurious techniques, which can be modified by coaching and training interventions to prevent injuries. This study thus has implications on coaching and training of fast bowlers in India.

Self-sustained non-equilibrium co-existence of fluid and solid states in a strongly coupled complex plasma system.

A complex (dusty) plasma system is well known as a paradigmatic model for studying the kinetics of solid-liquid phase transitions in inactive condensed matter. At the same time, under certain conditions a complex plasma system can also display characteristics of an active medium with the micron-sized particles converting energy of the ambient environment into motility and thereby becoming active. We present a detailed analysis of the experimental complex plasmas system that shows evidence of a non-equilibrium stationary coexistence between a cold crystalline and a hot fluid state in the structure due to the conversion of plasma energy into the motion energy of microparticles in the central region of the system. The plasma mediated non-reciprocal interaction between the dust particles is the underlying mechanism for the enormous heating of the central subsystem, and it acts as a micro-scale energy source that keeps the central subsystem in the molten state. Accurate multiscale simulations of the system based on combined molecular dynamics and particle-in-cell approaches show that strong structural nonuniformity of the system under the action of electostatic trap makes development of instabilities a local process. We present both experimental tests conducted with a complex plasmas system in a DC glow discharge plasma and a detailed theoretical analysis.

Prophylaxis for preventing venous thromboembolism in knee arthroscopy and soft tissue reconstruction: consensus statements from an international panel of experts.

PURPOSE: There is a lack of consensus regarding need for Venous Thrombo Embolism (VTE) prophylaxis following arthroscopic knee surgery and open soft tissue knee reconstruction. Clear cut guidelines like ones for trauma surgery and arthroplasty do not exist and the published literature is limited to case reports with a few society guidelines. Given this lack of consensus, we conducted a modified Delphi questionnaire of international experts to provide recommendations on this topic. METHODS: The consensus statements were generated using an anonymised 3 round modified Delphi questionnaire, sent to an international panel of 38 knee surgeons, with an 80% agreement being set as the limit for consensus. The responses were analysed using descriptive statistics with measures like mode, median and box plots. Feedback was provided to all panelists based on responses from the previous rounds to help generate the consensus. RESULTS: Six consensus statements were generated after the three rounds of Delphi. Patient factors, prolonged surgery duration and family history of thrombogenic events emerged as the main points to be taken into consideration for prophylaxis. CONCLUSION: It was established through this study, that there exists a select group of patients undergoing arthroscopic surgery that justify the usage of VTE prophylaxis. The expert responses to most of the questions in different scenarios favoured usage of VTE prophylaxis based on patient factors like advanced age, past history of VTE, smoking, oral contraceptive use etc. LEVEL OF EVIDENCE: Level V.

Rac1 activation can generate untemplated, lamellar membrane ruffles.

BACKGROUND: Membrane protrusions that occur on the dorsal surface of a cell are an excellent experimental system to study actin machinery at work in a living cell. Small GTPase Rac1 controls the membrane protrusions that form and encapsulate extracellular volumes to perform pinocytic or phagocytic functions. RESULTS: Here, capitalizing on rapid volumetric imaging capabilities of lattice light-sheet microscopy (LLSM), we describe optogenetic approaches using photoactivable Rac1 (PA-Rac1) for controlled ruffle generation. We demonstrate that PA-Rac1 activation needs to be continuous, suggesting a threshold local concentration for sustained actin polymerization leading to ruffling. We show that Rac1 activation leads to actin assembly at the dorsal surface of the cell membrane that result in sheet-like protrusion formation without any requirement of a template. Further, this approach can be used to study the complex morpho-dynamics of the protrusions or to investigate specific proteins that may be enriched in the ruffles. Deactivating PA-Rac1 leads to complex contractile processes resulting in formation of macropinosomes. Using multicolour imaging in combination with these approaches, we find that Myo1e specifically is enriched in the ruffles. CONCLUSIONS: Combining LLSM and optogenetics enables superior spatial and temporal control for studying such dynamic mechanisms. Demonstrated here, the techniques implemented provide insight into the complex nature of the molecular interplay involved in dynamic actin machinery, revealing that Rac1 activation can generate untemplated, lamellar protrusions.

Knee flexion strength deficits correlate with distal extent of tendon regeneration after hamstring harvest. Preliminary data from an Ultrasound based classification.

BACKGROUND: As more evidence comes to light that hamstring harvesting may not be as benign a procedure as previously thought, considerable interest is being generated towards corelating the knee flexural strength deficits with the degree of tendon regeneration. The current study aimed to corelate knee flexion strength deficits with ultrasonographically quantified degree of hamstring regeneration after tendon harvest. STUDY DESIGN: 31 patients of ACL reconstruction with hamstring grafts were divided into 2 groups (6 months and 1-year post op) according to time of follow up. Ultrasonography of both the knees to assess Semitendinosus tendon dimensions was done. Regeneration was classified as non-significant, mild (Zone 1, till 4 cm above the lateral joint line), moderate (Zone 2 ,at the level of the lateral joint line) and significant (Zone 3, 1.5 cm below the lateral joint line) as the regenerate happens from proximal to distal. Regenerate dimensions were compared with US measurements from the opposite knee. Bilateral isokinetic strength tests of the knees were done to evaluate flexion strength, and strength deficits were compared with degree of tendon regeneration. RESULTS: 14 (45%) of cases had no regeneration at both time periods. 7 patients (41%) in the 6-month post-op group showed some form of regeneration, and 10 patients (71%) in the 1-year post-op group showed regeneration. 29/31 patients had some flexion strength deficit. Strength deficit correlated with the level and degree of tendon regeneration, with non-significant regeneration cases showing higher strength deficit (mean - 28.51%), and cases with significant regeneration showing least amount of strength deficit (mean - 3.66%). CONCLUSION: Flexion strength deficits after hamstring harvest are significant and corelate with degree of tendon regeneration, which improves over time. US is adequate to quantify degree of tendon regeneration, which in turn can help prognosticate return of flexion strength.

Rapid whole cell imaging reveals a calcium-APPL1-dynein nexus that regulates cohort trafficking of stimulated EGF receptors.

The endosomal system provides rich signal processing capabilities for responses elicited by growth factor receptors and their ligands. At the single cell level, endosomal trafficking becomes a critical component of signal processing, as exemplified by the epidermal growth factor (EGF) receptors. Activated EGFRs are trafficked to the phosphatase-enriched peri-nuclear region (PNR), where they are dephosphorylated and degraded. The details of the mechanisms that govern the movements of stimulated EGFRs towards the PNR, are not completely known. Here, exploiting the advantages of lattice light-sheet microscopy, we show that EGFR activation by EGF triggers a transient calcium increase causing a whole-cell level redistribution of Adaptor Protein, Phosphotyrosine Interacting with PH Domain And Leucine Zipper 1 (APPL1) from pre-existing endosomes within one minute, the rebinding of liberated APPL1 directly to EGFR, and the dynein-dependent translocation of APPL1-EGF-bearing endosomes to the PNR within ten minutes. The cell spanning, fast acting network that we reveal integrates a cascade of events dedicated to the cohort movement of activated EGF receptors. Our findings support the intriguing proposal that certain endosomal pathways have shed some of the stochastic strategies of traditional trafficking and have evolved processes that provide the temporal predictability that typify canonical signaling.

Characterization and application of rhamnolipid from Pseudomonas plecoglossicida BP03.

The production of rhamnolipid (glycolipid) biosurfactant was achieved under optimized conditions from newly isolated bacteria (Pseudomonas plecoglossicida BP03) from rice mill effluent. The isolated biosurfactant was structurally characterized using FTIR and NMR spectroscopic studies. The obtained biosurfactant (1·39 g l-1 ) showed a variety of applications including larvicidal and pupicidal activity against malarial vector (Anopheles sunadicus). It also exhibited antimicrobial activity against human pathogens, and possessed potent anti-biofilm activity against Staphylococcus aureus, Bacillus subtilis and Aeromonas hydrophila. The obtained biosurfactant showed a dose-dependent inhibition of exopolymeric substance (EPS) and growth curve in S. aureus. Furthermore, the cytotoxicity assays revealed that the biosurfactant exhibit a cytotoxic potency against the human fibroblastic sarcoma cells Ht-1080. An in silco analysis was also performed using Schrodinger maestro 9.3 against surface protein (SasG) of S. aureus, and the resultant analysis revealed an interactive docking score of -3·4 kcal mol-1 . The obtained result indicates that the synthesized economically viable biosurfactant ensures excellent applications towards various fields.

Evaluation of regeneration of semitendinosus tendon using ultrasound imaging and isokinetic strength testing after graft harvest for arthroscopic anterior cruciate ligament reconstruction.

BACKGROUND: A lot of the research has been done worldwide evaluating the capacity of the semitendinosus tendon to regenerate which has not been conducted in the Indian population. STUDY DESIGN: 31 patients who underwent unilateral ACL reconstruction with hamstrings were taken into study. All patients underwent ultrasonography imaging of both knees and bilateral isokinetic flexion strength assessment at a one-year postoperative period. Images were obtained at three levels and their dimensions are compared with normal side. Isokinetic testing of the knee is done to evaluate the flexion deficit and is compared to the uninvolved knee. RESULTS: Out of a total of 31 patients, 14 patients showed no regeneration, 17 showed regeneration at various levels. On isokinetic testing patients with no regeneration showed the highest mean flexion deficit. CONCLUSION: The semitendinosus tendon and its regeneration can be visualized well using ultrasonography. After semitendinosus harvesting, the flexion strength will be decreased as compared to the normal knee. The flexion strength in patients who have a regenerated tendon will be higher as compared to those who have no regeneration.

Personal Protective Equipment (PPE) Guidelines, adaptations and lessons during the COVID-19 pandemic.

The COVID-19 pandemic has placed unprecedented strain on the American healthcare system. Personal protective equipment (PPE) remains critical in keeping healthcare providers healthy and safe. The sudden increase in demand as well as the limited availability places increased risk on providers which may inhibit their ability to effectively manage patients. The purpose of this brief article is to review the recommended guidelines for PPE usage and compare them to how medical societies have adapted and responded to decreased supply, as well as public response.

La pandémie de COVID-19 a exercé une pression sans précédent sur le système de santé américain. Les équipements de protection individuelle (EPI) restent essentiels pour assurer la santé et la sécurité des prestataires de soins de santé. L'augmentation soudaine de la demande ainsi que la disponibilité limitée font courir un risque accru aux prestataires, ce qui peut entraver leur capacité à gérer efficacement les patients. L'objectif de ce bref article est de passer en revue les lignes directrices recommandées pour l'utilisation des EPI et de les comparer à la manière dont les sociétés médicales se sont adaptées et ont réagi à la diminution de l'offre, ainsi qu'à la réaction du public.

Spectroscopic assessment on the stability of benzophenone crystals at shock waves loaded condition.

In recent years, there have been few thousands of non-linear optical (NLO) materials proposed for a wide array of technological applications. But unfortunately, most of the materials do not fit into the actual standard required for the specific purposes in terms of their efficiency, environmental resistance, cost effectiveness, availability, stability and durability. Hence, searching for the most suitable material for every specific technological application has become the necessity of being a continuous process until it is found. For the present experiment, we have chosen benzophenone crystal for the shock wave recovery experiment. Raman and powder X-ray diffraction (XRD) techniques have been utilized to evaluate the molecular and structural performances of the title material against the impact of shock waves and the obtained crystallographic structural properties are compared with potassium dihydrogen phosphate (KPD) crystal. The obtained Raman and XRD results demonstrate that the title material has high shock resistant property even though it is a mechanically soft material as well as it has very low melting point (48 °C).

Rowing Injuries in Elite Athletes: A Review of Incidence with Risk Factors and the Role of Biomechanics in Its Management.

BACKGROUND: Rowing is an Olympic sport gaining popularity in India and injuries are common in these athletes. Determinants of performance, injury risk and training are all interrelated in rowing. Injuries result from various risk factors including fitness issues and improper techniques. Rowers should have adequate leg extension strength and lumbo-pelvic coordination to produce and transmit power from the legs to the oar handle. Biomechanical analysis of the rowing stroke can help in preventing injuries and optimise technique for best performance. It involves a detailed and systematic observation of movement patterns to establish the quality of the movement and provide feedback to the rower about the key variables affecting performance and injury risk. Kinetics such as foot forces and kinematics such as key joint angles can be accurately measured by instrumented foot stretcher and three-dimensional motion capture. AIM: To do a detailed review of literature regarding the incidence and risk factors for rowing injuries and to get an insight on the role of biomechanics in its management. MATERIALS AND METHODS: Literature review was carried out with standard academic search engines and databases including Science Direct, PubMed and Google Scholar using keywords of relevance. A total number of 38 articles were analysed and results were collated to compile this review report. RESULTS: Lumbar spine is most commonly injured (up to 53%), followed by rib cage (9-10%) and shoulder and other anatomical areas. Rowers with a trunk-driven rowing action will have a lower hip:trunk score and carry a high injury risk. A player with lumbar injury will take a minimum of 3-4 months to recover. CONCLUSION: Rowing injuries are common. Regular screening of the rowing athletes by comprehensive fitness and biomechanics assessment will help in prevention of injuries. Rowers need to be tested for pain, strength, flexibility, reproducibility of rowing action with modified mechanics, coordination, fatigue level, explosive power, aerobic and anaerobic endurance. Early recognition of risk factors and timely intervention is the key aspect of a successful return to play.

Understanding pretreatment loss to follow-up of tuberculosis patients: an explanatory qualitative study in Chennai, India.

Introduction: Pretreatment loss to follow-up (PTLFU)-dropout of patients after diagnosis but before treatment registration-is a major gap in tuberculosis (TB) care in India and globally. Patient and healthcare worker (HCW) perspectives are critical for developing interventions to reduce PTLFU. Methods: We tracked smear-positive TB patients diagnosed via sputum microscopy from 22 diagnostic centres in Chennai, one of India's largest cities. Patients who did not start therapy within 14 days, or who died or were lost to follow-up before official treatment registration, were classified as PTLFU cases. We conducted qualitative interviews with trackable patients, or family members of patients who had died. We conducted focus group discussions (FGDs) with HCWs involved in TB care. Interview and FGD transcripts were coded and analysed with Dedoose software to identify key themes. We created categories into which themes clustered and identified relationships among thematic categories to develop an explanatory model for PTLFU. Results: We conducted six FGDs comprising 53 HCWs and 33 individual patient or family member interviews. Themes clustered into five categories. Examining relationships among categories revealed two pathways leading to PTLFU as part of an explanatory model. In the first pathway, administrative and organisational health system barriers-including the complexity of navigating the system, healthcare worker absenteeism and infrastructure failures-resulted in patients feeling frustration or resignation, leading to disengagement from care. In turn, HCWs faced work constraints that contributed to many of these health system barriers for patients. In the second pathway, negative HCW attitudes and behaviours contributed to patients distrusting the health system, resulting in refusal of care. Conclusion: Health system barriers contribute to PTLFU directly and by amplifying patient-related challenges to engaging in care. Interventions should focus on removing administrative hurdles patients face in the health system, improving quality of the HCW-patient interaction and alleviating constraints preventing HCWs from providing patient-centred care.

Influence of pressure on the transport, magnetic, and structural properties of superconducting Cr0.0009NbSe2 single crystal.

We investigate the superconducting critical current density (J c), transition temperature (T c), and flux pinning properties under hydrostatic pressure (P) for Cr0.0009NbSe2 single crystal. The application of P enhances T c in both electrical resistivity (∼0.38 K GPa-1: 0 ≤ P ≤ 2.5 GPa) and magnetization (∼0.98 K GPa-1: 0 ≤ P ≤ 1 GPa) measurements, which leads to a monotonic increase in J c and flux pinning properties. The field-dependent J c at various temperatures under P is analyzed within the collecting pinning theory and it shows that δT c pinning is the crossover to δl pinning above the critical pressure (P c ∼0.3 GPa). Our systematic analysis of the flux pinning mechanism indicates that both the density of pinning centers and pinning forces greatly increase with the application of P, which leads to an enhancement in the vortex state. Structural studies using synchrotron X-ray diffraction under pressure illustrate a stable hexagonal phase without any significant impurity phase and lattice parameter reduction with P shows highly anisotropic nature.

A chitosan grafted mesoporous carbon aerogel for ultra-sensitive voltammetric determination of isoniazid.

A screen-printed carbon electrode (SPCE) was modified with chitosan (Chit) supported on carbon aerogel (CA) to obtain an electrochemical sensor for the tuberculosis drug isoniazid (INZ). The interconnected mesoporous structure of Chit/CA provides a large surface area (SBET = 461 m2 g-1) and good porosity (VTot = 0.69 cm3 g-1). Besides, the modified SPCE displayed enhanced electrocatalytic activity due to the presence of numerous active sites (such as >C=O, -NH-, -NH2, -OH). Figures of merit include (a) a typical working voltage of 0.28 V (vs. Ag/AgCl), (b) high sensitivity (8.09 µA µM-1 cm-2), (c) a wide linear response to INZ (0.01-115 µM) and (d) a low detection limit (8 nM). The modified electrode has successfully been applied to the determination of INZ in spiked serum and urine, and recoveries ranged from 97.8 to 99.8%. Graphical abstract Schematic illustration of preparation and applications of a nanocomposite consisting of chitosan (Chit; CS) supported on carbon aerogel (CA) for electrochemical detection of isoniazid.

Efficient nitrogen-vacancy centers' fluorescence excitation and collection from micrometer-sized diamond by a tapered optical fiber in endoscope-type configuration.

Using an optical fiber to both excite the nitrogen-vacancy (NV) center in diamond and collect its fluorescence is essential to build NV-based endoscope-type sensor. Such endoscope-type sensor can reach inaccessible fields for traditional NV-based sensors built by bulky optical components and extend the application areas. Since single NV's fluorescence is weak and can easily be buried in fluorescence from optical fiber core's oxide defects excited by the green laser, fixing a micrometer size diamond containing high-density NVs rather than a nanodiamond containing single NV or several NVs on the apex of an optical fiber to build an endoscope-type sensor is more implementable. Unfortunately, due to small numerical aperture (NA), most of the optical fibers have a low fluorescence collection efficiency, which limits the sensitivity and spatial resolution of the NV-based endoscope-type sensor. Here, using a tapered optical fiber (TOF) tip, we significantly improve the efficiency of the laser excitation and fluorescence collection of the NV ensembles in diamond. This could potentially enhance the sensitivity and spatial resolution of the NV-based endoscope-type sensor. Numerical calculations show that the TOF tip delivers a high NA and has a high NV excitation and fluorescence collection efficiency. Experiments demonstrate that such TOF tip can obtain up to over 7-fold excitation efficiency and over 15-fold fluorescence collection efficiency of that from a flat-ended fiber (non-TOF) tip.

Complex magnetic structure and magnetocapacitance response in a non-oxide NiF2 system.

We report here on the complex magnetic structure and magnetocapacitance in NiF2, a non-oxide multifunctional system. It undergoes an anti-ferromagnetic transition near 68.5 K, superimposed with canted Ni spin driven weak ferromagnetic ordering, followed by a metastable ferromagnetic phase at or below 10 K. Our density functional calculations account for the complex magnetic structure of NiF2 deduced from the temperature and the field dependent measurements. Near room temperature, NiF2 exhibits a relatively large dielectric response reaching >103 with a low dielectric loss of <0.5 at frequencies >20 Hz. This is attributed to the intrinsic grain contribution in contrast to the grain boundary contribution in most of the known dielectric materials. The response time is 10 µs or more at 280 K. The activation energy for such temperature dependent relaxation is ~500 meV and is the main source for grain contribution. Further, a large negative magneto capacitance >90% is noticed in 1 T magnetic field. We propose that our findings provide a new non-oxide multifunctional NiF2, useful for dielectric applications.

Effect of Bi-functional Hierarchical Flower-like CoS Nanostructure on its Interfacial Charge Transport Kinetics, Magnetic and Electrochemical Behaviors for Supercapacitor and DSSC Applications.

Metal sulfides are of great interest for future electrode materials in supercapacitor and solar cell applications owing to their superior electrochemical activity and excellent electrical conductivity. With this scope, a binary transition metal sulfide (CoS) is prepared via one-step hydrothermal synthesis. Hexagonal phase of CoS with space group of P63/mmc(194) is confirmed by XRD analysis. Additional cubic Co3S4 phase in the prepared sample originates the mixed valence state of Co (Co2+ and Co3+) is affirmed from XPS analysis. Morphological features are visualized using HRSEM images that shows nanoflower shaped star-anise structure. Employing the prepared CoS as active electrode material, interfacial charge transport kinetics is examined by EIS-Nyquist plot. The supercapacitive performances are tested in two and three-electrode system which exhibited respective specific capacitances of 57 F/g and 348 F/g for 1 A/g. Further, the fabricated asymmetric CoS//AC supercapacitor device delivers an appreciable energy density of 15.58 Wh/kg and power density of 700.12 W/kg with excellent cyclic stability of 97.9% and Coulombic efficiency of 95% over 2000 charge-discharge cycles. In addition, dye-sensitized solar cells are fabricated with CoS counter electrode and the obtained power conversion efficiency of 5.7% is comparable with standard platinum based counter electrode (6.45%). Curie-Weiss plot confirms the transition of paramagnetic nature into ferrimagnetic behavior at 85 K and Pauli-paramagnetic nature at 20 K respectively. Temperature dependent resistivity plot affirms the metallic nature of CoS sample till 20 K and transition to semiconducting nature occurs at <20 K owing to Peierl's transition effect.

Enhancement of superconducting properties and flux pinning mechanism on Cr0.0005NbSe2 single crystal under Hydrostatic pressure.

Superconducting properties of Cr0.0005NbSe2 (Tc~6.64 K) single crystals have been investigated through the temperature dependent resistivity (~8 GPa) and DC magnetization (~1 GPa) measurements. Further, the critical current density (Jc) as a function of applied magnetic field has been studied from magnetic isotherms. The vortex pinning mechanisms have also been systematically analyzed using weak collective pinning theory as a function of pressure. The Jc corresponds to the flux flow enhanced by the application of pressure due to increase of Tc and vortex changes. We found that the pressure is responsible for the spatial variations in the charge carrier mean free path (δl pinning). We find that core point pinning is more dominant than surface pinning which is caused by the application of pressure. In addition, Jc(H = 0) increases from 3.9 × 105 (0 GPa) to 1.3 × 106 (1.02 GPa) A/cm2 at 2 K as the pressure is increased from normal pressure to 1.02 GPa. The pressure dependence of Tc (dTc/dP) becomes 0.91 K/GPa and 0.75 K/GPa from magnetization and resistivity measurements respectively. We found that the pressure promotes the anisotropy nature, and decrease of coherence length and resulting in pathetic interface of the vortex core with pinning centers.

The Evidence for External Beam Radiotherapy in High-Risk Neuroblastoma of Childhood: A Systematic Review.

AIMS: External beam radiotherapy is widely used in various ways in the management of neuroblastoma. Despite extensive clinical experience, the precise role of radiotherapy in neuroblastoma remains unclear. The purpose of this systematic review was to survey the published literature to identify, without bias, the evidence for the clinical effectiveness of external beam radiotherapy as part of the initial multimodality treatment of high-risk neuroblastoma. We considered four areas: treatment of the tumour bed and residual primary tumour, identification of any dose-response relationship, treatment of metastatic sites, identification of any technical advances that may be beneficial. We also aimed to define uncertainties, which may be clarified in future clinical trials. MATERIALS AND METHODS: Bibliographic databases were searched for neuroblastoma and radiotherapy. Reviewers assessed 1283 papers for inclusion by title and abstract, with consensus achieved through discussion. Data extraction on 57 included papers was carried out by one reviewer and checked by another. Studies were assessed for their level of evidence and risk of bias, and a descriptive analysis of data was carried out. RESULTS: Fifteen papers provided some evidence that radiotherapy to the tumour bed and residual tumour may possibly be of value. However, there is a significant risk of bias and no evidence that all subgroups will benefit. There is some suggestion from six papers that dose may be important, but no hard evidence. It remains unclear whether irradiation of metastatic sites is helpful. Technical advances may be of value in radiotherapy of high-risk neuroblastoma. CONCLUSIONS: There are data that show that radiotherapy is of some efficacy in the management of high-risk neuroblastoma, but there is no level one evidence that shows that it is being used in the best possible way. Prospective randomised trials are necessary to provide more evidence to guide development of optimal radiotherapy treatment schedules.

Comparison of multi-institutional pre-treatment verification for VMAT of nasopharynx with delivery errors.

PURPOSE: Measurement-based pre-treatment verification with phantoms frequently uses gamma analysis to assess acceptable delivery accuracy. This study evaluates the sensitivity of a commercial system to simulated machine errors for three different institutions' Volumetric Modulated Arc Therapy (VMAT) planning approaches. METHODS: VMAT plans were generated for ten patients at three institutions using each institution's own protocol (manually-planned at institution 1; auto-planned at institutions 2 and 3). Errors in Multi-Leaf Collimator (MLC) field size (FS), MLC shift (S), and collimator angle (C) of -5, -2, -1, 1, 2 and 5 mm or degrees were introduced. Dose metric constraints discriminated which error magnitudes were considered unacceptable. The smallest magnitude error treatment plans deemed clinically unacceptable (typically for a 5% dose change) were delivered to the ArcCHECK for all institutions, and with a high-dose point ion chamber measurement in 2 institutions. Error detection for different gamma analysis criteria was compared. RESULTS: Not all deliberately introduced VMAT plan errors were detected using a typical 3D 3%/3 mm global gamma pass rate of 95%. Considering all institutions, gamma analysis was least sensitive to negative FS errors. The most sensitive was a 2%/2 mm global analysis for institution 1, whilst for institution 2 it was 3%/3 mm global analysis. The majority of errors (58/59 for institution 1, 54/60 for institution 3) were detected using ArcCHECK and ion chamber measurements combined. CONCLUSIONS: Not all clinically unacceptable errors are detected. Combining ion chamber measurements with gamma analysis improved sensitivity and is recommended. Optimum gamma settings varied across institutions.