Irradiated Components Research Articles

Longevity study of a triple-GEM chamber for the HL-LHC upgrade

As part of the high-luminosity LHC (HL-LHC) upgrade, the CMS muon spectrometer will extend its coverage in the very forward region with triple-GEM detectors. These detectors will cope with a harsh environment with expected background fluxes up to 150 kHz/cm (Sauli, 2016) [2]. At the end of HL-LHC operation, the total accumulated charge at the hottest point is expected to reach 7.9 C/cm (Sauli, 2016) [2]. This accumulated charge is unprecedented for a GEM detector.A full-size triple-GEM chamber was built using the design planned for the most forward CMS muon station using GEM foils produced at CERN. While operated with a gas mixture of Ar/CO2 (70/30)%, the chamber was irradiated with photons from a silver-target X-ray source over 1.5 years to reach an accumulated charge of 8 C/cm2. Before and after irradiation the chamber was validated using the standard quality control procedures; gas gain and energy resolution were measured. During irradiation the gain was monitored weekly. The irradiation was interrupted only for the certification measurements. A non-irradiated sector was monitored for comparison. Temperature and pressure in the lab were continuously measured to derive correction factors to calibrate the gas gain. No degradation in gas gain was observed when reaching 8 C/cm2. Irradiated and non-irradiated chamber components were inspected for potential impacts from irradiation.

Influence of neutron decay on nuclear reactor materials

While many of the leading factors for material degradation in irradiated reactor components have been identified through past studies, spontaneous neutron decay within components is a factor absent in the literature. The byproducts of neutron decay, largely composed of a proton, could lead to excessive hydrogen content, irradiation assisted stress corrosion cracking, epsilon martensite formation, hydrides, ion induced damage, voids, bubbles, and dislocation loops. Neutrons are the most abundant relevant fission product, and neutrons are continuously decaying at a rate proportional to their production. This paper hypothesizes that at high neutron fluence, a quantifiable contribution to material degradation can be associated with the proton byproducts of neutron decay. Literature-based degradation mechanisms are presented along with initial calculations of the neutron decay contribution. The paper will demonstrate a potential new factor for consideration in the material degradation of nuclear reactor components.

Consequences of Neutron Energy Spectrum on Radiation Damage, Gas Production, and Transmutations in Fusion Materials

The inclusion of test modules in the U.S. Fusion Prototypic Neutron Source (FPNS) offers the opportunity to test a wide variety of materials in a representative radiation environment of the fusion Pilot Plant, DEMO, and power plant. The testing may include various generations of structural materials for conventional and advanced blanket and divertor concepts. Since all structural materials derived from the fission industry are inadequate for fusion applications (due to the more damaging effects of the 14-MeV fusion neutrons), radiation-resistant reduced-activation structural materials (reduced-activation ferritic-martensitic steel, vanadium alloy, W alloy, and SiC/SiC composites) were specifically developed for fusion and could be tested in the FPNS to qualify for the highly irradiated fusion components surrounding the plasma. The large atomic displacement and the helium and hydrogen generations by fusion neutrons are unique to fusion materials. The most important attribute for the FPNS would be the typical fusion-relevant He/displacements per atom (dpa) ratio of ~10 for steel in particular. By comparison, irradiation in the fission spectrum of the High Flux Irradiation Facility (HFIR) would underestimate the dpa and provide a very low He/dpa ratio of ~0.3 for steel, which is irrelevant to fusion. This paper reviews the neutron irradiation impacts and presents a few examples of dpa and transmutation products for steel, W, and SiC based on modeling in several fusion design studies. The operating conditions of advanced U.S. fusion power plants were considered along with the credible lifetime goal of 200 dpa and 20 MW·yr/m2 fluence that could be achieved with directed research and development programs coupled with the construction of the FPNS 14-MeV neutron facility.

Macro-scale modeling of finite strain viscoplasticity in irradiated F/M steels: a continuum thermodynamic framework

The European reduced activation ferritic/martensitic steel Eurofer97 in irradiated states displays significant nonlinear material behavior involving irradiation hardening, loss of strain hardening, and uniform elongation, as well as irradiation-induced embrittlement. Nonlinear behavior of irradiated steel modeled on the continuum scale will help to estimate the maximum operating range of the irradiated components beyond the onset of localized plastic flow. In this work, a thermodynamic framework for modeling irradiation-influenced deformation is established based on irradiation defect density and a thermodynamically consistent finite strain formulation of an existing viscoplastic model using the Dual Variables concept is presented. The model is implemented in ABAQUS allowing the simulation of tensile tests conducted on irradiated and unirradiated materials which shows the model’s ability to capture the post-yield and post-necking behavior observed in experiments up to ductile failure.

Beam test studies with silicon sensor module prototypes for the CMS Phase-2 Outer Tracker

The Large Hadron Collider (LHC) at CERN will be upgraded to the High-Luminosity LHC (HL-LHC) by 2029. In order to fully exploit the physics potential of the high luminosity era the experiments must undergo major upgrades. In the context of the upgrade of the Compact Muon Solenoid (CMS) experiment the silicon tracker will be fully replaced. The outer part of the new tracker (Outer Tracker) will be equipped with about 13,000 double-layer silicon sensor modules with two different flavors: PS modules consisting of a macro-pixel and a strip sensor and 2S modules using two strip sensors. These modules can discriminate between trajectories of charged particles with low and high transverse momentum. The different curvature of the trajectories in the CMS magnetic field leads to different hit signatures in the two sensor layers. By reading out both sensors, matching hits in the seed and correlation layer “stubs” are identified. This stub information is generated at the LHC bunch crossing frequency of 40 MHz and serves as input for the first stage of the CMS trigger. In order to quantify the hit and stub detection efficiency, beam tests have been performed. This article comprises selected studies from measurements gathered during two beam tests at the DESY test beam facility with 2S prototype modules assembled in 2021, featuring the Low Power Gigabit Transceiver (lpGBT). In order to compare the module performance at the beginning and end of the CMS runtime, a module with irradiated components has been built and intensively tested.

Hematopoietic Stem Cell Transplantation in Bangladesh : Activity and Outcome Update

Background : Hematopoietic stem cell transplantation(HSCT) is a potentially life saving curative modality of treatment procedure for many hematological malignancies, bone marrow failure syndromes and thalassemia. Bangladesh started first bone marrow transplant program with autologous transplant for myeloma in 2014 with the international collaboration between Massachusetts general hospital ( MGH) and Dhaka Medical College Hospital (DMCH). Since then it is growing in both public and private sector hospitals. Method : This is a multicenter retrospective study describing the demographics, activities and outcome of HSCT in Bangladesh. HSCT related Data were collected from three eminent HSCT centres of Bangladesh ( DMCH, Evercare hospitals and Combined Military Hospital Dhaka) and were analyzed. Result : As of June 2022, total 163 HSCT have been done in Bangladesh in major three centres as DMCH(52), Evercare hospital (62)and CMH Dhaka(49). Mean age of all patients is 39.4 years( range 15-69 Y) and sex distribution is M:F 3:1. Total autologous transplants were 125(77%) for myeloma(52), Hodgkins lymphoma(27) ,non-Hodgkins lymphoma(39) and others(7). Total allogeneic transplants were 38(23%) for AML(23), ALL(6), other hematological malignancy(03), Severe aplastic anemia (04) and thalassemia (02). Donor type wise majority were from matched sibling transplant (30/78%) from mostly male donor. Eight (08) haplo transplant were also successfully done. Each center follows specific infection control protocols, conditioning chemo protocols and growth factor protocols for the best patient care. Conditioning chemo protocols that usually used are high dose melphalan for MM, BEAM( Carmustine, Etoposide, Ara-C and Melphalan) for lymphoma and Bu-Cy( Busulphan-Cyclophosphamide) based for acute leukemia. Some leukemia patients received total body irradiation( TBI), thiotepa and Fludarabine based conditioning chemotherapy. All centres use irradiated blood components as transfusion products to avoid transfusion associated GVHD. As all centre used almost similar conditioning for particular disease, mean engraftment time in all centres were almost similar. Average time for neutrophil and platelet engraftment was 10-12 and 12-16 days post transplant respectively. Major early complications following transplant were neutropenic fever (>80%) and bacteraemia (25-30%) commonly with coagulase negative Staphylococcus, Pseudomonas sp, E. Coli and Klebsiella sp. Severe sepsis, pneumonia, typhlitis, hemorrhagic cystitis and CMV reactivation were observed in few cases. Acute GVHD ( G I to GII) was observed in almost all allogeneic transplanted patients. Mucositis, vomiting and diarrhoea were mild to moderate in most patients. Almost all patients required at least 1-3 red cell and platelet transfusion during the time waiting for engraftment. Progression free survival for all patients was variable in different centres (62% to 83%) since 2014 . Relapse of primary disease is more observed in autologous than allogeneic. Transplant related mortality( TRM) was 2% for autologous transplants and 5% for allogeneic transplant. Three early deaths were due to sepsis with COVID-19 infection in autologous transplant in pandemic period. Overall cost of transplantation is much lower in Bangladesh than that of developed countries. Approximate cost of autologous stem cell transplant is about $7000 and that for allogeneic transplant is $12000 to $15,000. Conclusion : Considering total population and burden of hematological malignancy in Bangladesh, the number of transplant is very low and it needs to be grown more rapidly to provide maximum benefit to save the lives as HSCT offers a curative approach to many hematological malignancies. Financial constrain, lack of health insurance and shortage of trained human resource are the main challenges for doing transplant in Bangladesh. National transplant registry and national donor registry both are yet to be developed. Comparing the cost difference with developed countries the overall outcome of stem cell transplantation is not inferior in Bangladesh.

Haematopoietic Stem Cell Transplantation: A Single Center Experience of Four Years in Bangladesh

Background: Haematopoietic stem cell transplantation (HSCT) is the standard consolidation therapy for a variety of malignant and non-malignant diseases in children and adults. Our experience of HSCT in 26 patients with various indications is shared in this article. Materials and methods: This was a retrospective analysis of first 26 patients who had undergone autologous and allogeneic transplant at our center, with M:F=2.7:1. The mean age for autologous transplant was 45 years (range 23-57 years). The median follow-up period was 23 months 25 days (range 3to 47 months).The data was obtained carefully from medical records of the BMT center. Indications for autologous HSCT were Multiple Myeloma (12 patients), Non- Hodgkin’s lymphoma (7 patients), Hodgkin’s lymphoma (4 patients). Allogeneic HSCT were for Acute Myeloid Leukaemia (3 patients). Results: The mean time for WBC engraftment was 12 days (range: 9-19 days) and for platelet engraftment was 16 days (range: 11-35 days) in our autologous transplant cases and for allogeneic transplant mean time for WBC engraftment was12 days (range: 11-15 days) and for platelet engraftment was 14 days (range: 12-17 days). Irradiated blood components were given in the pre, peri and post-transplant period to maintain Hb>8 gm/dl and platelet count >20X109/L. Mean single-donor platelet requirement was 4 units (range 1-7), and mean packed red cell requirement was 1.5 units (range 1-6). The post-transplant complications encountered were mucositis, infections and diarrhoea. Oral mucositis was the most common complications. Twenty three (88.46 %) out of our 26 HSCT patients had developed mucositis , among them grade 1 in 5 patients, grade 2 in 11 patients, and grade 3 in 7 patients. There were 21(80.76%) cases of febrile neutropenia. Out of 26 patients 13 (50.0%) bacterial infection were documented with culture positivity. One (3.84%) case of viral infection was documented. Major bacterial infections were culture positive with Pseudomonas, Escherichia coli and Klebsiella followed by other species like acinatobacter, burkholderia and coagulase negative staphylococcus. One case of Cytomegalovirus was noted with significant viral copies that required Ganciclovir. Average duration of hospital stay after autologous HSCT was 23 days (range of 14-54 days) and allogeneic HSCT was 35 days (range of 30-57 days). 19 out of our 23 autologous transplant patients were in complete remission and all 03 cases of allogeneic HSCT were in remission. Conclusion: We believe our center has made a remarkable progress within short period of time to develop both autologous and allogeneic HSCT and is comparable with nationally and internationally renowned HSCT centers in terms of standard, quality and safety of care, and the ultimate outcomes. J Bangladesh Coll Phys Surg 2022; 40: 146-152

Effects of Freshly Irradiated vs Irradiated and Stored Red Blood Cell Transfusion on Cerebral Oxygenation in Preterm Infants

Gamma irradiation of leukoreduced red blood cells (RBCs) prevents transfusion-associated graft-vs-host disease but also exacerbates storage lesion formation in RBCs. It is unknown whether freshly irradiated RBCs are more efficacious than irradiated and stored RBCs in preterm infants with high transfusion requirements. To examine whether transfusion of freshly irradiated vs irradiated and stored RBC components improves cerebral oxygen delivery in preterm infants with anemia. This single-center, double-blinded, proof-of-concept randomized clinical trial was conducted at the neonatal intensive care unit of Wellington Regional Hospital in Wellington, New Zealand, between December 1, 2017, and November 30, 2018. Participants were preterm infants (<34 weeks' gestation at birth) who were at least 14 days of age and had anemia. Participants underwent nonurgent transfusions, and these episodes were randomized to the intervention group (in which the infants received a transfusion of RBCs that were freshly irradiated on the day of transfusion) or control group (in which the infants received a transfusion of RBCs that were irradiated and stored for up to 14 days). Data were analyzed using the evaluable population approach. Transfusion of freshly irradiated RBCs. The prespecified primary outcome was the change in cerebral regional oxygen saturation (crSO2) from baseline (immediately before) to immediately after the transfusion. The prespecified secondary outcomes were the change in cerebral fractional tissue oxygen extraction (cFTOE) at different time points (immediately after, 24 hours after, and 120 hours or 5 days after transfusion). Outcomes were measured by blinded clinicians using near-infrared spectroscopy. A covariate-adjusted linear mixed model was used to quantify mean treatment effects and account for multiple transfusions in some infants. A total of 42 infants (mean [SD] gestational age, 26 [10] weeks and 3 days; 29 [69%] boys) were enrolled in the trial and underwent 64 transfusion episodes, which were randomized to the intervention (n = 31) or control (n = 33) group. Compared with infants in the control group, those in the intervention group showed a covariate-adjusted mean increase in crSO2 (2.0 percentage points; 95% CI, 1.2-2.8 percentage points) and a mean decrease in cFTOE (0.02; 95% CI, 0.01-0.04) immediately after transfusion. These differences were sustained up to 120 hours or 5 days after transfusion. There were negligible mean changes in crSO2 or cFTOE in infants in the control group at any of the follow-up time points. Results of this trial showed that transfusion of freshly irradiated RBCs conferred a small advantage in cerebral oxygenation for at least 5 days after transfusion compared with transfusion of irradiated and stored RBC components. On-demand irradiation of RBC components may be considered to optimize oxygen delivery in the recipient, but this physiological finding requires further research. ANZCTR Identifier: ACTRN12617001581358.

Transfusion-associated graft-versus-host disease, transfusion-associated hyperkalemia, and potassium filtration: advancing safety and sufficiency of the blood supply

Irradiation of cellular blood components is well established as a countermeasure against transfusion-associated graft-versus-host disease (TA-GVHD). Unintended consequences of ionizing radiation are also well established. The red cell “storage lesion” – a progression of metabolic, functional, and morphological changes – may be exacerbated by irradiation rates and doses typically used for TA-GVHD prophylaxis. With or without irradiation, a storage lesion change of clinical concern is the accelerated egress of intracellular potassium. ATP depletion during storage limits the activity of the red cell membrane’s sodium-potassium pump (Na,K-ATPase), which normally maintains intracellular potassium (K+) at levels 30–40 times higher than the extracellular milieu. The natural diffusion of potassium down this concentration gradient proceeds faster if the cell membrane is damaged, and oxidative damage to cellular membranes and membrane proteins – including Na,K-ATPase – is an effect of ionizing radiation.Preventing transfusion-related hyperkalemia is a reason for limiting the shelf life of irradiated red cells. In the absence of specific measurements to assess storage lesion in a particular unit of blood, and in the absence of specific interventions at the time of transfusion to mitigate effects of storage lesion, it is consistent with the precautionary principle to put conservative limits on a blood component’s shelf life. On the other hand, both the safety and sufficiency of a nation’s blood supply might be improved by interventions that benefit specific recipients when they are transfused, and benefit future patients by extending the allowable shelf life of blood components. Potassium filtration of irradiated red blood cell components is one such intervention.

Universal or selective irradiation: a comparison of approaches

Pathological mechanisms proposed for transfusion-associated graft-versus-host diseases (TA-GVHD) include HLA homozygosity in donor cells of the transfusion unit that is shared by the recipient (one-way HLA match) and immunosuppression in the transfusion recipient. Which of these factors is indispensable or to what degree each factor contributes to the development of TA-GVHD has been the issue of debate. In countries like Japan with higher HLA homogeneity, TA-GVHD occurrence was thought to be primarily dependent on the one-way HLA match mechanism regardless of immunosuppression. Accordingly, universal irradiation of blood components has been conducted with no further TA-GVHD cases. In other developed countries, in contrast, TA-GVHD was thought to be a sort of extrapolation of GVHD observed among heavily immunosuppressed patients. Guidelines with the detailed list of diseases with the indication for irradiated components have been established in those countries. Although TA-GVHD occurrence decreased markedly after the introduction of universal leukoreduction, a considerable number of TA-GVHD cases have occurred among immunocompetent patients mostly by the one-way HLA match mechanism. Because one-way HLA matching with donor homozygosity is thought to be a ubiquitous and independent mechanism for TA-GVHD, it could occur in any transfusion setting regardless of immunosuppression. It would be thoughtful to select an area-specific strategy considering the drawbacks of irradiation and the frequency of TA-GVHD in that area. However, if complete abolition of TA-GVHD is required from the perspective of the high fatality of the disorder, universal irradiation of cellular components will be necessary.

Cytopenias in CAR-T Cell Therapy and Use of Transfusion Resources in Adult Patients with Lymphoproliferative Disorders

BACKGROUND AND OBJECTIVESCD19-directed chimeric antigen receptor (CAR)-T-cell therapy is associated with early cytopenia in approx. 80% of patients and late cytopenia in 40% of patients. To date, the transfusion profile of patients undergoing these therapies has not been described. Our objectives are: •To define the transfusion profile of CAR-T therapy in our setting.•To evaluate clinical variables related to the intensity and duration of cytopenias.METHODOLOGYThis is an observational, prospective, single centre study. Adult patients with lymphoproliferative disorders and acute lymphoblastic leukaemia proposed for CAR-T therapy from August 2019 to March 2021 were included.RESULTS68 patients were included in the CAR-T cell therapy program. Table 1 describes patients characteristics. Forty-seven received CART therapy, apheresis was not performed in 7 cases (progression n=6, withdrawal of consent n=1), product was not infused in 9 patients due to disease progression and 5 patients are awaiting infusion.Cytokine release syndrome (CRS) occurred in 79% of patients, 25% developed grade≥2 and median time to onset was 2 days (IQR, 1-4 days). Immune effector cell-associated neurotoxicity syndrome (ICANS) occurred in 33% of patients, 16% were grade≥3 and median time to onset was 7 days (IQR, 6-8 days). Median duration of hospital admission was 14 days (IQR, 12 to 21 days).None of the 47 infused patients had neutropenia or anemia in the transfusion range prior to lymphodepletion. 94% (44/47) developed grade ≥3 neutropenia, with a median duration of 14.5 days (IQR, 9.75 to 36 days). G-CSF was administered to 21 patients, with a median time on G-CSF of 115 days (IQR, 27-258 days). A total of 239 red blood cells units (RBC) have been transfused, median 3.5 RBC/patient (IQR, 0 to 7.5 RBC / patient). 70% of this consumption occurred in the first 30 days after infusion.Before CAR T cell infusion, 2 patients had a platelet count <20x10 9/L, and 3 between 30 and 50x10 9/L, mean platelets (SD) prior to lymphodepletion was 153 (+/-106) x10 9/L. Grade ≥3 thrombocytopenia occurred in 53% of patients, median time to reach platelets > 20x10 9/L was 17 days (IQR, 4-54 days) and > 50x10 9/L was 39 days (IQR, 20-79 days). 62% of patients received ≤2 platelet concentrates (PC). However, 21% had long-term thrombocytopenia (> 30 days). This group received a median of 15 PC (IQR, 12-27). The amount of PC used was 198, 52% were administered in the first 30 days. Eltrombopag was indicated in 9 of the 25 patients with grade ≥3 thrombocytopenia, doses never exceeded 75 mg/day. No serious bleeding (WHO grade ≥2) was observed.Factors related to severe thrombocytopenia were female (74% vs 42%, p=0.036), CRS (61% vs 0%, p=0.019), ICANS (80% vs 43%, p=0.020) and use of steroids (92% vs 67%, p=0.003). We found no relationship with underlying disease or status, prior treatment lines, prior autologous transplantation, CAR-T product, duration of lymphopenia, time and duration of CRS or ICANS.With a median follow-up of 167 days (IQR, 73-303 days), 26% of patients died, causes of death were infections n=2 and disease progression n=10. Three months after the procedure, there were 30 evaluable patients for response and 64% remained in remission (47% CR, 17% PR).CONCLUSIONSA high percentage of patients receiving CAR T cell therapy present long-term cytopenias. Reserves of irradiated blood components must be foreseen. Development of CRS and ICANS could be prognostic factors for the development of long-term grade ≥3 thrombocytopenia. Studies are needed on the use of thrombopoietin receptor agonists to reduce the duration of thrombocytopenia, although effective doses could be higher than those used in idiopathic immune thrombocytopenia. [Display omitted] DisclosuresReguera: Janssen, Kite/Gilead, Novartis: Speakers Bureau; BMS-Celgene, Novartis: Membership on an entity's Board of Directors or advisory committees. Perez-Simon: JANSSEN, TAKEDA, PFIZER, JAZZ, BMS, AMGEN, GILEAD: Other: honorarium or budget for research projects and/or participation in advisory boards and / or learning activities and / or conferences.

Evaluation of the in-situ performance of neutron detectors based on EJ-426 scintillator screens for spent fuel characterization

The reliable detection of neutrons in a harsh gamma-ray environment is an important aspect of establishing non-destructive methods for the characterization of spent nuclear fuel. In this study, we present results from extended in-situ monitoring of detector systems consisting of commercially available components: EJ-426, a 6Li-enriched solid-state scintillator material sensitive to thermal neutrons, and two different types of Hamamatsu photomultiplier tubes (PMT). Over the period of eight months, these detectors were operated in close vicinity to spent nuclear fuel stored at the interim storage facility CLAB, Oskarshamn, Sweden. At the measurement position the detectors were continuously exposed to an estimated (moderated) neutron flux of approx. 280n/scm2 and a gamma-ray dose rate of approximately 6Sv/h.Using offline software algorithms, neutron pulses were identified and characterized in the data. Over the entire investigated dose range of up to 35kGy, the detector systems were functioning and were delivering detectable neutron signals. Their performance as measured by the number of identified neutrons degrades down to about 30% of the initial value. Investigations of the irradiated components suggest that this degradation is a result of reduced optical transparency of the involved materials as well as a reduction of PMT gain due to the continuous high currents. Increasing the gain of the PMT through step-ups of the applied high voltage allowed to partially compensate for this loss in detection sensitivity even when the detectors were highly irradiated.The integrated neutron fluence during the measurement was experimentally verified to be in the order of 5×109ncm−2. The results were interpreted with the help of MCNP6.2 simulations of the setup and the neutron flux.

IRRADIATED BLOOD PRODUCTS-INSTITUTE PORTUGUESE OF ONCOLOGY – COIMBRA (IPOC) – EXPERIENCE OF BLOOD QUALITY ASSURANCE

The risks and benefits in the transfusion medicine are a great challenges for blood quality assurance. They must be sufficient to support answers to the acute and late effects. The irradiation of blood components for avoid Graft Versus Host Disease (GVHD) isn't different. The Medicine Transfusional Service(MST) – IPOC have procedures considered of excellence in Portugal-Central that take a good prevention for DHEC. Goals: This work has with objectives introduce our procedures and results for irradiated blood components to Central Portugal region by 1 year. The MST-IPOC irradiated blood components (CE – erythrocyte concentrate, PP – platelets pool and CUP – platelet concentrate unit by apheresis) for internal and external hospitals use, principally to central region at Portugal and we work with Physical Medicine to maintain the quality of this service that is included in the European hemovigilance system. We has a IBL 437C irradiator since 1997 and use RAD-SURE type 25Gy hand tags and supporting labels of irradiation, separated records to internal and external irradiation, description step by step since activation doctor/technical staff and the pos tranfusional tracking of GVHD around all irradiated units in this service. Our results: 60 % CE, 70% PP and 100% CUP of all irradiated components are used in IPOC internally and 72% of those irradiated from external institutions were University Hospital of Coimbra. 94% and 6% CE, 93% and 7 % PP had irradiated for adults and children, respectively. In the evaluation of acute or late GVHD we hadnt been positive case notified in the last years. We considered that our answer are the result of our quality procedures and the good training in this process.

Guidelines: the same evidence but different conclusions - relaxation of indications for irradiation of cellular blood components?

Guidelines: the same evidence but different conclusions - relaxation of indications for irradiation of cellular blood components?

Guideline development for prevention of transfusion-associated graft-versus-host disease: reduction of indications for irradiated blood components after prestorage leukodepletion of blood components.

Transfusion-associated graft-versus-host disease (TA-GVHD) is a rare, commonly fatal complication of transfusion preventable by irradiation of blood units. The revision of the Dutch transfusion guideline addressed the question whether irradiation is still necessary if blood components are prestorage leukodepleted. We searched for published cases of TA-GVHD following transfusion of prestorage leukodepleted blood and through contacting haemovigilance systems. Six presumed cases were found, dating from 1998 to 2013. Four out of six patients had received one or more non-irradiated units despite recognised indications for irradiated blood components. In the countries providing information, over 50 million prestorage leukodepleted, non-irradiated, non-pathogen-reduced cellular components were transfused in a 10-year period. Potential benefits of lifting indications for irradiation were considered. These include reduced irradiation costs (€ 1.5 million annually in the Netherlands) and less donor exposure for neonates. Findings were presented in an invitational expert meeting. Recommendations linked to human leukocyte antigen similarity between donor and recipient or intra-uterine transfusion were left unchanged. Indications linked to long-lasting deep T-cell suppression were defined with durations of 6 or 12 months after end of treatment (e.g. autologous or allogeneic stem cell transplantation). Need for continued alertness to TA-GVHD and haemovigilance reporting of erroneous non-irradiated transfusions was emphasised.

A way Analyzing Oxide Layer on an Irradiated CANDU-PHWR Pressure Tube Using an EPMA and X-ray Image Mapping

The oxide layer in samples taken from an irradiated Zr-2.5Nb pressure tube from a CANDU-PHWR reactor was analyzed using electron probe microanalysis (EPMA). The examined tube had been exposed to temperatures ranging from 264 to 306 ℃ and a neutron fluence of 8.9 × 1021 n/㎠ (E > 1 MeV) for the maximum 10 effective full-power years in a nuclear power plant. Measuring oxide layer thickness generally employs optical microscopy. However, in this study, analysis of the oxide layer from the irradiated pressure tube components was undertaken through X-ray image mapping obtained using EPMA. The oxide layer characteristics were analyzed by X-ray image mapping with 256 × 256 pixels using EPMA. In addition, the slope of the oxide layer was measured for each location. A particular advantage of this study was that backscattered electrons and X-ray image mapping were obtained at a magnification of 9,000 when 20 kV volts and 30 uA of current were applied to radiation-shielded EPMA. The results of this study should usefully contribute to the study of the oxide layer properties of various types of metallic materials irradiated by high radiation in nuclear power plants.

A Study on Reusable Metal Component as Burnable Absorber Through Monte Carlo Depletion Analysis

After nuclear power plants are permanently shut down and decommissioned, the remaining irradiated metal components such as stainless steel, carbon steel, and Inconel can be used as neutron absorber. This study investigates the possibility of reusing these metal components as neutron absorber materials, that is burnable poison. The absorption cross section of the irradiated metals did not lose their chemical properties and performance even if they were irradiated over 40-50 years in the NPPs. To examine the absorption capability of the waste metals, the lattice calculations of WH 17×17 fuel assembly were analyzed. From the results, Inconel-718 significantly hold-down fuel assembly excess reactivity compared to stainless steel 304 and carbon steel because Inconel-718 contains a small amount of boron nuclide. From the results, a 20wt% impurity of boron in irradiated Inconel-718 enhances the excess reactivity suppression. The application of irradiated Inconel-718 as a burnable absorber for SMR core was investigated. The irradiated Inconel-718 impurity with 20wt% of boron content can maintain and suppress the whole core reactivity. We emphasize that the irradiated metal components can be used as burnable absorber materials to control the reactivity of commercial reactor power and small modular reactors.

Missed irradiation of cellular blood components for vulnerable patients: Insights from 10 years of SHOT data.

BackgroundIrradiation of cellular blood components is recommended for patients at risk of transfusion‐associated graft‐vs‐host disease (TA‐GvHD). Prestorage leucodepletion (LD) of blood components is standard in the UK since 1999.Study Design and MethodsAnalysis of 10 years' reports from UK national hemovigilance scheme, Serious Hazards of Transfusion (2010‐2019), where patients failed to receive irradiated components when indicated according to British Society for Haematology guidelines (2011).ResultsThere were 956 incidents of failure to receive irradiated components all due to errors. One hundred and seventy two incidents were excluded from analysis, 125 of 172 (72.7%) because of missing essential information. No cases of TA‐GvHD were reported in this cohort. The 784 patients received 2809 components (number unknown for 67 incidents). Most failures occurred in patients treated with purine analogues (365) or alemtuzumab (69), or with a history of Hodgkin lymphoma (HL) (192). Together these make up 626 of 784 (79.9%). Poor communication is an important cause of errors.ConclusionLeucodepletion appears to reduce the risk for TA‐GvHD. None of 12 cases of TA‐GvHD reported to SHOT prior to introduction of LD occurred in patients with conditions recommended for irradiated components by current guidelines. Irradiation indefinitely for all stages of HL is not based on good evidence and is a difficult guideline to follow. Further research on long‐term immune function in HL is required. Variation between different national guidelines reflects the very limited evidence.

BSH guidelines for the use of irradiated blood components: guidance that is needed.

BSH guidelines for the use of irradiated blood components: guidance that is needed.

A Case of Recurrent Acute Pain Transfusion Reactions Due to Platelet Transfusion

Abstract Introduction/Objective Transfusion of blood components is one of the most common medical procedures with transfusion reactions being the greatest associated risk. Acute pain transfusion reaction (APTR) is one such under- recognized and under-reported risk, likely due to scarcity of literature and lack of criteria for diagnosis. Methods A literature review was performed using PubMed to search for the keywords: “acute pain transfusion reaction”. This searched revealed two articles, from which one abstract and a book chapter were also identified. Results A 58-year-old female with chronic myeloid leukemia and pre-existing pain received 44 leukoreduced irradiated blood components [7 pooled platelets, 17 apheresis platelets, 20 red blood cells (RBCs)] over two months. Four platelet (one pooled, three apheresis) transfusions resulted in chest and lower back pain starting an average of 15 minutes after initiation of transfusion and resolving following cessation of transfusion. Laboratory evaluations were negative for hemolysis. Despite the patient’s history of pain, these reactions were most consistent with APTRs. APTRs are rare, most often associated with leukoreduced RBCs and characterized by severe pain in the abdomen, back, flank, or proximal extremities typically occurring within 30 minutes of starting transfusion and abating within 30 minutes following cessation of transfusion. All of our patient’s reported reactions occurred in association with leukoreduced platelets. These reactions may be associated with the leukoreduction, but reports of APTR appeared when leukoreduction became standard practice. Therefore, the etiology remains unknown. Conclusion This case aids in the argument that APTR is a complication of transfusion, despite the absence of a clear etiology or diagnostic criteria. Additional research and improved surveillance are necessary to elucidate potential etiology and improve patient care by identifying prevention and treatment options. A diagnostic criterion would aid efforts to harmonize reporting in the United States and collect the hemovigilance data required to improve transfusion outcomes.