Maximum Allowable Difference Research Articles

Assessing a GPS-Based 6-Minute Walk Test for People With Persistent Pain: Validation Study.

The 6-minute walk test (6MWT) is a commonly used method to assess the exercise capacity of people with many health conditions, including persistent pain. However, it is conventionally performed with in-person supervision in a hospital or clinic, therefore requiring staff resources. It may also be difficult when in-person supervision is unavailable, such as during the COVID-19 pandemic, or when the person is geographically remote. A potential solution to these issues could be to use GPS to measure walking distance. The primary aim of this study was to assess the validity of a GPS-based smartphone app to measure walking distance as an alternative to the conventional 6MWT in a population with persistent pain. The secondary aim of this study was to estimate the difference between the pain evoked by the 2 test methods. People with persistent pain (N=36) were recruited to complete a conventional 6MWT on a 30-m shuttle track and a 6MWT assessed by a smartphone app using GPS, performed on outdoor walking circuits. Tests were performed in random order, separated by a 15-minute rest. The 95% limits of agreement were calculated using the Bland-Altman method, with a specified maximum allowable difference of 100 m. Pain was assessed using an 11-point numerical rating scale before and after each walk test. The mean 6-minute walk distance measured by the GPS-based smartphone app was 13.2 (SD 46; 95% CI -2.7 to 29.1) m higher than that assessed in the conventional manner. The 95% limits of agreement were 103.9 (95% CI 87.4-134.1) m and -77.6 (95% CI -107.7 to -61) m, which exceeded the maximum allowable difference. Pain increased in the conventional walk test by 1.1 (SD 1.0) points, whereas pain increased in the app test by 0.8 (SD 1.4) points. In individuals with persistent pain, the 2 methods of assessing the 6MWT may not be interchangeable due to limited validity. Potential reasons for the differences between the 2 methods might be attributed to the variation in track layout (shuttle track vs continuous circuit); poor GPS accuracy; deviations from the 30-m shuttle track; human variability in walking speed; and the potential impact of a first test on the second test due to fatigue, pain provocation, or a learning effect. Future research is needed to improve the accuracy of the GPS-based approach. Despite its limitations, the GPS-based 6MWT may still have value as a tool for remote monitoring that could allow individuals with persistent pain to self-administer frequent assessments of their functional capacity in their home environment.

Determination of the Convergence of Intra-Laboratory Measurements of Dust Content on a Construction Site

Introduction. Intra-laboratory comparison tests play an important role in ensuring the quality and reliability of research outcomes in laboratories. These tests allow researchers to evaluate the accuracy and reproducibility of the methods they use in their work, as well as to identify potential sources of error and inconsistency. The results of these tests are shared with experts to confirm competence within the accreditation. Typically, comparison tests are carried out in laboratory conditions in a familiar and calm environment for the testers. However, when laboratories conduct research as part of a special assessment of working conditions (SAWC) they are required to conduct on-site comparisons at real-world facilities, where customers may unwittingly disrupt the process and directly affecting the quality of the measurements. The aim of this study is to evaluate the quality of on-site intra-laboratory comparison tests using the example of determining the dust content in a bricklayer's work environment on a construction site, and to determine the minimum number of measurements necessary and sufficient for this purpose.Materials and Methods. To determine the dustiness of the bricklayer's workplace, a weighing method was used. This involved collecting dust on filters and then weighing them to determine the concentration. The quality assessment of intra-laboratory tests was conducted in accordance with GOST R ISO 5725-1-2002 "Accuracy (trueness and precision) of measurement methods and results. Part 1. General principles and definitions".Results. At the bricklayer's workplace, a 1.6-fold excess of the one-time maximum permissible dust concentration was detected. The average dust concentration at the workplace under study was: Kp2 = 9.57 ± 0.81 mg/m3, the convergence of the results obtained was r = 8.68 %, the relative error δ = 8.50 %. It was revealed that the maximum allowable difference between the results of the two tests was 0.84 mg/m3. The difference in direct measurements of the mass of the two samples should be no more than 0.1 mg.Discussion and Conclusion. The results obtained demonstrated the possibility of conducting a minimum number of measurements that, under reproducible conditions, are considered satisfactory and could be provided to experts for confirming the competence of the laboratory. As part of a special assessment of working conditions, employees of the object under study are recommended to use personal respiratory protection equipment that offers protection against highly dispersed dust particles.

Internet of things temperature control of indirect dual tank heat storage system in solar photo-thermal power plant

In order to study the temperature control of the IoT for indirect dual tank heat storage systems in solar thermal power plants, the author proposes a refined design method for heat storage systems. Through CFD software FLUENT analysis, the author proposes a temperature control scheme for storage tanks in solar thermal power plants and applies this method to the temperature control and salt injection processes of actual commercial power plants. The refined design of a systematic heat storage system mainly involves precise calculation of molten salt content and refined analysis of overall and local stresses in the storage tank. For molten salt storage tanks with a diameter of about 30 m, every 1 cm of liquid level design error will result in economic losses of tens of thousands of Yuan. In addition, the design process of storage tanks should fully consider temperature control, salt injection, and some special operating conditions during operation. By numerically simulating the flow process of flue gas and molten salt in the storage tank and the real-time wall temperature of the storage tank, a temperature control scheme that does not exceed the maximum allowable wall temperature difference of the storage tank is obtained to reduce thermal stress during the temperature control process of the storage tank, reduce the risk and failure rate of the storage tank. The temperature control scheme has achieved good results in practical projects.

Simulation study on the influence of longitudinal dynamic force on extreme-long heavy-haul trains

PurposeThe objective of this study is to investigate the impact of longitudinal forces on extreme-long heavy-haul trains, providing new insights and methods for their design and operation, thereby enhancing safety, operational efficiency and track system design.Design/methodology/approachA longitudinal dynamics simulation model of the super long heavy haul train was established and verified by the braking test data of 30,000 t heavy-haul combination train on the long and steep down grade of Daqing Line. The simulation model was used to analyze the influence of factors on the longitudinal force of super long heavy haul train.FindingsUnder normal conditions, the formation length of extreme-long heavy-haul combined train has a small effect on the maximum longitudinal coupler force under full service braking and emergency braking on the straight line. The slope difference of the long and steep down grade has a great impact on the maximum longitudinal coupler force of the extreme-long heavy-haul trains. Under the condition that the longitudinal force does not exceed the safety limit of 2,250 kN under full service braking at the speed of 60 km/h the maximum allowable slope difference of long and steep down grade for 40,000 t super long heavy-haul combined trains is 13‰, and that of 100,000 t is only 5‰.Originality/valueThe results will provide important theoretical basis and practical guidance for further improving the transportation efficiency and safety of extreme-long heavy-haul trains.

Hagnifinder: Recovering magnification information of digital histological images using deep learning

Background and objectiveTraining a robust cancer diagnostic or prognostic artificial intelligent model using histology images requires a large number of representative cases with labels or annotations, which are difficult to obtain. The histology snapshots available in published papers or case reports can be used to enrich the training dataset. However, the magnifications of these invaluable snapshots are generally unknown, which limits their usage. Therefore, a robust magnification predictor is required for utilizing those diverse snapshot repositories consisting of different diseases. This paper presents a magnification prediction model named Hagnifinder for H&E-stained histological images. MethodsHagnifinder is a regression model based on a modified convolutional neural network (CNN) that contains 3 modules: Feature Extraction Module, Regression Module, and Adaptive Scaling Module (ASM). In the training phase, the Feature Extraction Module first extracts the image features. Secondly, the ASM is proposed to address the learned feature values uneven distribution problem. Finally, the Regression Module estimates the mapping between the regularized extracted features and the magnifications. We construct a new dataset for training a robust model, named Hagni40, consisting of 94 643 H&E-stained histology image patches at 40 different magnifications of 13 types of cancer based on The Cancer Genome Atlas. To verify the performance of the Hagnifinder, we measure the accuracy of the predictions by setting the maximum allowable difference values (0.5, 1, and 5) between the predicted magnification and the actual magnification. We compare Hagnifinder with state-of-the-art methods on a public dataset BreakHis and the Hagni40. ResultsThe Hagnifinder provides consistent prediction accuracy, with a mean accuracy of 98.9%, across 40 different magnifications and 13 different cancer types when Resnet50 is used as the feature extractor. Compared with the state-of-the-art methods focusing on 4–5 levels of magnification classification, the Hagnifinder achieves the best and most comparable performance in the BreakHis and Hagni40 datasets. ConclusionsThe experimental results suggest that Hagnifinder can be a valuable tool for predicting the associated magnification of any given histology image.

Evaluation and management of leukolysis-mediated pseudohyperkalemia in paediatric leukemic samples.

IntroductionLeukolysis-related pseudohyperkalemia due to preanalytical procedures may lead to erroneous (or absence of) treatment based on an invalid lab test result. We aimed to obtain a leukocyte threshold above which leukolysis-related pseudohyperkalemia becomes clinical relevant. Secondly, temporal dynamics of treatment-induced leukocyte decrease were studied to allow tailored implementation of laboratory information system (LIS) decision rules based on the leukocyte threshold to avoid leukolysis-related pseudohyperkalemia.Materials and methodsPotassium results of AU5811 routine chemistry (Beckman Coulter, Brea, California, USA) and iStat point of care (POC) (Abbott Diagnostics, Chicago, Illinois, USA) analysers were compared, the latter method being insensitive to leukolysis caused by pre-analytical procedures. Potassium results were combined with leukocyte counts obtained using a Cell-Dyn Sapphire haematology analyser (Abbott Diagnostics, Santa Clara, California, USA), resulting in 132 unique data triplets. Regression analysis was performed to establish a leukocyte threshold. The Reference Change Value (√2 x Z x √(CVa2 + CVi2)) was used to calculate maximum allowable difference between routine analyser and POC potassium results (deltamax + 0.58 mmol/L). Temporal analysis on the treatment-induced leukocyte decrease was performed by plotting leukocyte counts in time for all patients above the threshold leukocyte count (N = 41).ResultsEstablished leukocyte threshold was 63 x109/L. Temporal analysis showed leukocyte counts below the threshold within 8 days of treatment for all patients.ConclusionsBased on performed analyses we were able to implement LIS decision rules to reduce pseudohyperkalemia due to preanalytical procedures. This implementation can contribute to a reduction in erroneous (or absence of) treatments in the clinic.

A composite superconducting energy pipeline and its characteristics

A superconducting energy pipeline cooled during its clean energy transferring becomes attractive recently to be a promising alternative way for combined green energy transmission to meet the ever-rising energy demand across the world. Though, study on superconducting energy pipelines gets into the conceptual design of single energy integration, the critical multi-composite structure and its characteristics have not yet been systematical. A novel high-temperature superconducting (HTS) energy pipeline integrated with power cable and liquid hydrogen (LH2) and liquefied natural gas (LNG) is proposed in this paper. The maximum allowable temperature difference and pressure drop methods are adopted to design the pipeline. A two-dimensional axisymmetric electromagnetic thermal coupling model has been established using the finite element method. The interface magnetic field formulation, heat transfer modeling, and multiphysics interface has been applied to conduct a detailed analysis of the designed superconducting energy pipeline (LH2-LNG-HTSEP). The results show that the designed LH2-LNG-HTSEP is feasible for practical operation and has more favorite characteristics to suit the HTS cable for the composite pipeline operation. The model and analysis method provide a theoretical base for the composite superconducting energy pipeline design and structural optimization.

Dig That Lick (DTL): Analyzing Large-Scale Data for Melodic Patterns in Jazz Performances

Dig That Lick (DTL): Analyzing Large-Scale Data for Melodic Patterns in Jazz Performances

Brief Behavioral Treatment for Insomnia vs. Cognitive Behavioral Therapy for Insomnia: Results of a Randomized Noninferiority Clinical Trial Among Veterans

The goal of this study was to compare a brief behavioral treatment for insomnia (BBTI), which has fewer sessions (4), shorter duration (<30–45 minutes), and delivers treatment in-person plus phone calls to cognitive behavioral therapy for insomnia (CBTI), which has 5 in-person sessions. The hypothesis was BBTI would be noninferior to CBTI. The Reliable Change Index was used to establish a noninferiority margin (NIM) of 3.43, representing the maximum allowable difference between groups on the pre-post Insomnia Severity Index change (ΔISI). Sixty-three veterans with chronic insomnia were randomized to either BBTI or CBTI and veterans in both groups had significant reductions of their insomnia severity per the ISI and improved their sleep onset latency, total wake time, sleep efficiency, and sleep quality per sleep diaries. While CBTI had a larger pre-post ΔISI, this was not significantly different than ΔISI BBTI and was less than the NIM. However, the 95% confidence interval of the between group pre-post ΔISI extended beyond the NIM, and thus BBTI was inconclusively noninferior to CBTI. Limitations, such as small sample size and high rate of dropout, indicate further study is needed to compare brief, alternative yet complementary behavioral insomnia interventions to CBTI. Still, evidence-based brief and flexible treatment options will help to further enhance access to care for veterans with chronic insomnia, especially in non-mental-health settings like primary care.

Challenges of the Use of Sound Emergence for Setting Legal Noise Limits

In the vast majority of legislation on environmental noise, the metric used for expressing limit values is based on sound pressure levels. But some countries have introduced sound emergence limit values where the compliance of a noise-generating activity is defined as a maximum allowable difference between the sound pressure level with and without the regulated activity operating. This paper investigates the foundations and the merits of this kind of differential noise limit values. Our review of literature indicates that there is very little evidence supporting the use of differential noise limits over absolute ones. Moreover, while sound emergence limits seem to originate from consideration about audibility of the regulated noise source, they appear to give little insight into what is audible and what is not. Furthermore, both the definition and the practical measurement of sound emergence raise several challenges that compromise reproducibility. In addition, first, the reference to background noise makes it very difficult first to ascertain the conformity of noisy installations in the long run, second to effectively protect the community from excessive noise and third to evaluate conformity on the basis of simulations. When switching to another metric is not an option the paper makes recommendations toward a more reliable use of sound emergence.

Point-of-Care Fibrinogen Testing in Pregnancy.

Agreement between estimated fibrinogen concentration via thromboelastography and traditional assays is not established in the parturient. We therefore recruited 56 parturients and performed Clauss and functional fibrinogen level (FLEV) tests. Mean difference of measurements was 36.8 mg/dL (95% CI, 21.8-51.9) with a standard deviation of 52.8 mg/dL. Calculated limits of agreement were 140.2 mg/dL (95% CI, 166.3-114.6) and -66.6 mg/dL (95% CI, -40.8 to -92.5), within the maximum allowable difference of 165 mg/dL. We therefore conclude that while most measurements fell within the limits of agreement, more work is needed to clearly define the role of this test in the obstetric population.

Concept Design of 1 GW LH2-LNG-Superconducting Energy Pipeline

A 1 GW LH2-LNG-superconducting energy pipeline has been designed, and the design parameters under the consideration of the maximum allowable temperature difference and pressure drop are verified to achieve high efficiency.

Factorial analysis and experimental study of water-based cooling system effect on the performance of photovoltaic module

A study of the performance of a photovoltaic system with water cooling was carried out experimentally. Three main parameters, namely the water flow rate, the setpoint temperature of the photovoltaic panel, and the maximum allowable temperature difference of the photovoltaic panel, were investigated. In addition, the effect of dust accumulation, in terms of the cleanness factor, ambient temperature, and relative humidity, was studied. An experimental setup was constructed to investigate the cooling effect of water flowing over the panel surface on the performance of a photovoltaic module built at the campus of Jordan University of Science and Technology. Cooling of the photovoltaic module was performed for the period from June to September 2015. The photovoltaic module temperature was controlled to be between 30 and 50 °C, with different levels of water flow rate: high, medium, and low, i.e., 0.9, 0.6, and 0.3 m3/h, respectively. In addition, a statistical factorial analysis of the three-level full factorial design for the experimental data was conducted. It was found that the photovoltaic system performance was higher under water-cooling conditions. The optimum photovoltaic panels cooling temperature was shown to be 37 °C. The designed cooling system achieved an acceptable percentage of excess energy production, i.e., 15.28–17.75%, with minimum water losses. Furthermore, it was found from the statistical analysis that the setpoint temperature of the photovoltaic module had the largest effect on the percentage of excess energy production from photovoltaic, while the effect of maximum allowable temperature difference was negligible.

Evaluation and Completion the Design Methods of Pressure Vessels Flange Joints

We have provided a comparative analysis of the current international computing standards (European Standard EN 13445-3; ASME-Code, Section VIII, Division 2; British Standard (PD 5500: 2009)) that take into consideration only the static loading of flanges and bolts, if the temperatures of the flanges, bolts and sealing gasket are equal to each other and lower than creep temperature. The paper has put forth relations for completion the calculation method for flange joints in situations not taken into consideration by standards, namely: � static loading if flange temperature and bolt temperature are different; -thermal transient loading; � creep stress; � fatigue loading in the general case of a sequence of blocks of normal stresses. Furthermore, relationships have been proposed for the calculation of the maximum allowable difference between a flange and a bolt so as to ensure both the tightness and the mechanical strength of the flange joint.

Integrated compression of vehicle spatio‐temporal trajectories under the road stroke network constraint

AbstractWith fast growth of all kinds of trajectory datasets, how to effectively manage the trajectory data of moving objects has received a lot of attention. This study proposes a spatio‐temporal data integrated compression method of vehicle trajectories based on stroke paths coding compression under the road stroke network constraint. The road stroke network is first constructed according to the principle of continuous coherence in Gestalt psychology, and then two types of Huffman tree—a road strokes Huffman tree and a stroke paths Huffman tree—are built, based respectively on the importance function of road strokes and vehicle visiting frequency of stroke paths. After the vehicle trajectories are map matched to the spatial paths in the road network, the Huffman codes of the road strokes and stroke paths are used to compress the trajectory spatial paths. An opening window algorithm is used to simplify the trajectory temporal data depicted on a time–distance polyline by setting the maximum allowable speed difference as the threshold. Through analysis of the relative spatio‐temporal relationship between the preceding and latter feature tracking points, the spatio‐temporal data of the feature tracking points are all converted to binary codes together, accordingly achieving integrated compression of trajectory spatio‐temporal data. A series of comparative experiments between the proposed method and representative state‐of‐the‐art methods are carried out on a real massive taxi trajectory dataset from five aspects, and the experimental results indicate that our method has the highest compression ratio. Meanwhile, this method also has favorable performance in other aspects: compression and decompression time overhead, storage space overhead, and historical dataset training time overhead.

Short communication: Evaluation of an automated method for assessing white blood cell concentrations in Holstein dairy cows

Assessing white blood cell (WBC) differentials is one way to assess cow health and well-being. The objective of this study was to determine the agreement between WBC populations identified by manual evaluation via microscopy and an automated approach. Data were collected from mid-to-late lactation dairy cows sampled at 6-h intervals starting at 2100 over a 48 period (n = 192). The agreement between the two methods was calculated using a regression model in SAS (v9.4, SAS Institute Inc., Cary, NC) to construct limits of agreement. Data were analyzed by comparing the mean response of the methods for each sample against the difference between the methods The maximum allowable difference (MAD) was set at ±10% for each response variable. Agreement between methods was evident for neutrophils and lymphocytes, but not for monocytes and eosinophils. Agreement for these factors was established from an insignificant P-value, a low R2 value, and concentration of the data within the MAD. This data indicates that the automated method is appropriate for analysis of neutrophil and lymphocyte concentrations. However, accuracy needs to be improved for analysis of monocytes and eosinophils if differentiation of all WBC populations is necessary.

Development of an Automated Three-Phase Distribution Box System

Most electrical appliances require continuous power supply. For domestic use, crucial appliances such as refrigerator, aquarium and alarm system highly depend upon the continuity of power supply. However, if they are left without electricity due to power outage or blackouts caused by internal or external disturbance, the discontinuity of power supply could be a critical issue to some involving party. Blackouts may be due to short circuit, fault or the overloading of electricity mains. During power outage, Residual Current Device (RCD) detects fault currents from live to the neutral wire within circuit and will trip to prevent shock. This circumstance can increase safety when a house is left unoccupied. Be that as it may, the power will remain switched off until manually reset by man. Thus, this paper presented a new concept of Three-Phase distribution box system in order to overcome tripping problem. This system will be able to identify and isolate the fault using measurement of current flow into each Miniature Circuit Breaker (MCB) of appliances and current flowing out from each of the load. The measured current value will be compared and the maximum allowable difference is 30mA. If the current difference exceeds the maximum limit then the fault MCB will be detected. Hence RCD will be automatically close the circuit after determining the fault location via the motor operation to make sure of power stability and evade any property loss.

Heat Transfer Simulation of A-Frame Assembly to Support Alcator C-Mod Outer Divertor Upgrade

To design the Alcator C-Mod outer divertor to operate at 600°C and determine its effect on the surrounding vessel and diagnostics, heat transfer analysis must be performed. This paper describes the analysis and the results of heat transfer simulations of the outer divertor tiles, tile-mounting plate, support structure, and current shunt. Using Comsol, commercial FEA software package, a 3D wedge model that exploits the cyclic symmetry of the divertor, is created. By adjusting the power level of each of the 7 heaters used to elevate and control the divertor temperature, a uniform poloidal temperature distribution is achieved and the power requirements for the heaters are determined. The temperature of each component in the assembly is calculated, and results are used for further design changes. Additionally, radiation simulation on thermal shields are presented, which is used as ambient temperature for the heat transfer of the A-frame assembly. Furthermore, a full model of the entire outer divertor ring is presented with its toroidal temperature distribution. Finally, thermal stress of the plate is analyzed besides an analytical calculation of the maximum allowable temperature difference.

Vertical mixing layer development

A new generation of current and wave testing tanks is required to simulate more realistic sea conditions at larger scales. One means of producing a current is by using groups of impellers arranged around the perimeter of a circular tank. Each propeller produces a single flow velocity which may be different to its neighbours. These differences can lead to a stepped or curved plan view velocity profile in the test section of the tank where a plug profile is required. It is important to understand what the maximum allowable velocity difference between each impeller can be before the required plug profile in the test section is compromised.The situation where two individual fluid streams combine, leading to a turbulent mixing layer, is found in many applications and is therefore of great interest in wider fluid dynamics.In the experimental work presented a setup is described which combines two water flows at different velocities to create a vertical shear. The evolution of the combined flow is studied using Particle Image Velocimetry (PIV). When analysed, these results lead to an understanding of various aspects of mixing layer flow recovery and how the bulk flow rates and velocity ratio affected them.

Involved Field Radiotherapy Versus No Further Treatment in Patients with Clinical Stages IA and IIA Hodgkin Lymphoma and a ‘Negative' PET Scan After 3 Cycles ABVD. Results of the UK NCRI RAPID Trial

AbstractAbstract ▪547▪This icon denotes a clinically relevant abstractIn early stage HL abbreviated chemotherapy (ACT) followed by involved field radiotherapy (IFRT) is the current standard of care but some patients (pts) are probably cured by ACT alone. PET imaging has the potential to identify pts with an excellent prognosis after ACT and so provide the opportunity to avoid radiotherapy and reduce late treatment toxicity in these individuals. We present results of the RAPID trial evaluating PET response directed therapy in pts with previously untreated stages I and II HL, no B symptoms or mediastinal bulk. All pts taking part in RAPID received 3 cycles ABVD followed by a PET scan at one of fifteen quality controlled/assured PET Scan Centres across the UK. Acquired images were transmitted electronically to the Core Lab in London for central review. If the PET scan was reported ‘negative' (score 1 or 2 on a 5 point scale), pts were randomised between IFRT and no further treatment (NFT). Those with a ‘positive' PET scan (score 3, 4 or 5) had a 4th cycle ABVD and IFRT. This non-inferiority trial required 400 PET negative pts to be randomised for exclusion of a ≥7% difference in 3-year progression-free survival (PFS) from 95% in the IFRT arm, with 90% power and 5% significance level.602 pts (321 male, 281 female; median age 34 years) with newly diagnosed, stages IA/IIA HL were registered into the RAPID trial between October 2003 and August 2010. Following 3 cycles ABVD, 571 pts had a PET scan of which 426 (74.6%) were classified as PET negative (score 1, n=301; score 2, n=125). 420 PET negative pts were randomised to receive IFRT (n=209) or NFT (n=211); 6 PET negative pts were not randomised (pt choice, n=3, clinician choice, n=2; error, n=1). 22 of 209 pts randomised to receive IFRT did not receive this treatment because 16 pts (PET score 1, n=14; PET score 2, n=2) declined after they became aware of the randomisation decision, 5 had died and 1 developed pneumocystis jiroveci pneumonia.After a median follow-up of 45.7 months from randomisation, 384 of 420 (91.4%) PET negative pts are alive and progression-free, 29 (6.9%) are alive and have progressed and 7 (1.7%) have died giving a combined 3-year PFS of 92.2% and overall survival (OS) of 98.3% in the randomised population. In the IFRT arm of the randomised PET negative population, 194 pts are alive and progression-free, 9 have progressed, and 6 have died (pneumonitis, n=2; HL, n=1; cardiovascular disease, n=1; intracerebal haemorrhage, n=1; angioimmunoblastic T cell lymphoma, n=1). In the NFT arm 190 pts are alive and progression-free, 20 have progressed, and 1 has died (bronchopneumonia, n=1). 3-year PFS is 93.8% IFRT versus 90.7% NFT (risk difference −2.9%, 95% CI −10.7 to 1.4%; the lower limit marginally exceeds the maximum allowable difference of −7%) and 3-year OS is 97.0% IFRT versus 99.5% NFT. For the 145 PET positive pts who received a 4thcycle ABVD and IFRT, 126 are alive and progression-free, 11 progressed, and 8 died to give a 3-year PFS of 85.9% and OS of 93.9% from registration. These results are summarized in the Table.These results show that in early stage HL, pts with a negative PET after 3 cycles of ABVD have an excellent prognosis without any further treatment. The 3-year PFS is slightly higher in the PET negative pts receiving IFRT (93.8% vs 90.7%), where a non-inferiority margin of 7% was deemed acceptable. We conclude that in stages IA/IIA HL, RT is unnecessary in the 75% of pts who become PET negative after 3 cycles ABVD. Such a response adapted approach based on centrally reviewed PET imaging reduces treatment time and costs, improves tolerability and most importantly removes the burden of early and late toxicity of radiotherapy from the PET negative population. [Display omitted] Disclosures:No relevant conflicts of interest to declare.