Pulmonary function and chest CT abnormalities 3 months after discharge from COVID-19, 2020-2021: A nation-wide multicenter prospective cohort study from the Japanese respiratory society.

BACKGROUND: No comprehensive analysis of the pulmonary sequelae of coronavirus disease 2019 (COVID-19) in Japan based on respiratory function tests and chest computed tomography (CT) has been reported. We evaluated post-COVID-19 conditions, especially focusing on pulmonary sequelae assessed by pulmonary function tests and chest CT. METHODS: For this prospective cohort study, we enrolled 1069 patients who presented pneumonia at the time of admission in 55 hospitals from February 2020 to September 2021. Disease severity was classified as moderateⅠ, moderate II, and severe, defined primarily according to the degree of respiratory failure. The data on post-COVID-19 conditions over 12 months, pulmonary function, and chest CT findings at 3 months were evaluated in this study. Additionally, the impact of COVID-19 severity on pulmonary sequelae, such as impaired diffusion capacity, restrictive pattern, and CT abnormalities, was also evaluated. RESULTS: The most frequently reported post-COVID-19 conditions at 3 months after COVID-19 were muscle weakness, dyspnea, and fatigue (48.4%, 29.0%, and 24.7%, respectively). The frequency of symptoms gradually decreased over subsequent months. In pulmonary function tests at 3 months, the incidence of impaired diffusion capacity and restrictive pattern increased depending on disease severity. There also were differences in the presence of chest CT abnormalities at the 3 months, which was markedly correlated with the severity. CONCLUSION: We reported a comprehensive analysis of post-COVID-19 condition, pulmonary function, and chest CT abnormalities in Japanese patients with COVID-19. The findings of this study will serve as valuable reference data for future post-COVID-19 condition research in Japan.

Alexander disease with a novel GFAP insertion-deletion mutation mimicking progressive supranuclear palsy.

This report presents a case of Alexander disease showing clinical characteristics mimicking progressive supranuclear palsy (PSP). A 67-year-old woman complaining of motor disturbance exhibited severe atrophy of medulla, spinal cord, and midbrain tegmentum, as well as periventricular hyperintensity on cerebral MRI. Genetic analysis identified a novel in-frame deletion/insertion mutation in the exon 3 of the GFAP gene. Interestingly, neurological findings and decreased striatal uptake in dopamine transporter SPECT were suggestive of PSP. A novel GFAP gene mutation found in the present case may cause the unique clinical phenotype, which should be differentiated from PSP.

Plan complexity metrics for head and neck VMAT competition plans.

Previous plan competitions have largely focused on dose metric assessments. However, whether the submitted plans were realistic and reasonable from a quality assurance (QA) perspective remains unclear. This study aimed to investigate the relationship between aperture-based plan complexity metrics (PCM) in volumetric modulated arc therapy (VMAT) competition plans and clinical treatment plans verified through patient-specific QA (PSQA). In addition, the association of PCMs with plan quality was examined. A head and neck (HN) plan competition was held for Japanese institutions from June 2019 to July 2019, in which 210 competition plans were submitted. Dose distribution quality was quantified based on dose-volume histogram (DVH) metrics by calculating the dose distribution plan score (DDPS). Differences in PCMs between the two VMAT treatment plan groups (HN plan competitions held in Japan and clinically accepted HN VMAT plans through PSQA) were investigated. The mean (± standard deviation) DDPS for the 98 HN competition plans was 158.5 ± 20.6 (maximum DDPS: 200). DDPS showed a weak correlation with PCMs with a maximum r of 0.45 for monitor unit (MU); its correlation with some PCMs was "very weak." Significant differences were found in some PCMs between plans with the highest 20% DDPSs and the remaining plans. The clinical VMAT and competition plans revealed similar distributions for some PCMs. Deviations in PCMs for the two groups were comparable, indicating considerable variability among planners regarding planning skills. The plan complexity for HN VMAT competition plans increased for high-quality plans, as shown by the dose distribution. Direct comparison of PCMs between competition plans and clinically accepted plans showed that the submitted HN VMAT competition plans were realistic and reasonable from the QA perspective. This evaluation may provide a set of criteria for evaluating plan quality in plan competitions.

Dosimetric impact of MLC positional errors on dose distribution in IMRT.

Optimizing the positional accuracy of multileaf collimators (MLC) for radiotherapy is important for dose accuracy and for reducing doses delivered to normal tissues. This study investigates dose sensitivity variations and complexity metrics of MLC positional error in volumetric modulated arc therapy and determines the acceptable ranges of MLC positional accuracy in several clinical situations. Treatment plans were generated for four treatment sites (prostate cancer, lung cancer, spinal, and brain metastases) using different treatment planning systems (TPSs) and fraction sizes. Each treatment plan introduced 0.25-2.0 mm systematic or random MLC leaf bank errors. The generalized equivalent uniform dose (gEUD) sensitivity and complexity metrics (MU/Gy and plan irregularity) were calculated, and the correlation coefficients were assessed. Furthermore, the required tolerances for MLC positional accuracy control were calculated. The gEUD sensitivity showed the highest dependence of systematic positional error on the treatment site, followed by TPS and fraction size. The gEUD sensitivities were 6.7, 4.5, 2.5, and 1.7%/mm for Monaco and 8.9, 6.2, 3.4, and 2.3%/mm (spinal metastasis, lung cancer, prostate cancer, and brain metastasis, respectively) for RayStation. The gEUD sensitivity was strongly correlated with the complexity metrics (r = 0.88-0.93). The minimum allowable positional error for MLC was 0.63, 0.34, 1.02, and 0.28 mm (prostate, lung, brain, and spinal metastasis, respectively). The acceptable range of MLC positional accuracy depends on the treatment site, and an appropriate tolerance should be set for each treatment site with reference to the complexity metric. It is expected to enable easier and more detailed MLC positional accuracy control than before by reducing dose errors to patients at the treatment planning stage and by controlling MLC quality based on complexity metrics, such as MU/Gy.

Radiological imaging protection: a study on imaging dose used while planning computed tomography for external radiotherapy in Japan.

Previous studies have primarily focused on quality of imaging in radiotherapy planning computed tomography (RTCT), with few investigations on imaging doses. To our knowledge, this is the first study aimed to investigate the imaging dose in RTCT to determine baseline data for establishing national diagnostic reference levels (DRLs) in Japanese institutions. A survey questionnaire was sent to domestic RT institutions between 10 October and 16 December 2021. The questionnaire items were volume computed tomography dose index (CTDIvol), dose-length product (DLP), and acquisition parameters, including use of auto exposure image control (AEC) or image-improving reconstruction option (IIRO) for brain stereotactic irradiation (brain STI), head and neck (HN) intensity-modulated radiotherapy (IMRT), lung stereotactic body radiotherapy (lung SBRT), breast-conserving radiotherapy (breast RT), and prostate IMRT protocols. Details on the use of motion-management techniques for lung SBRT were collected. Consequently, we collected 328 responses. The 75th percentiles of CTDIvol were 92, 33, 86, 23, and 32 mGy and those of DLP were 2805, 1301, 2416, 930, and 1158 mGy·cm for brain STI, HN IMRT, lung SBRT, breast RT, and prostate IMRT, respectively. CTDIvol and DLP values in institutions that used AEC or IIRO were lower than those without use for almost all sites. The 75th percentiles of DLP in each treatment technique for lung SBRT were 2541, 2034, 2336, and 2730 mGy·cm for free breathing, breath holding, gating technique, and real-time tumor tracking technique, respectively. Our data will help in establishing DRLs for RTCT protocols, thus reducing imaging doses in Japan.

The Effectiveness and Safety of Long-Term Macrolide Therapy for COPD in Stable Status: A Systematic Review and Meta-Analysis.

Background: Chronic obstructive pulmonary disease (COPD) is a prevalent condition with fewer treatments available as the severity increases. Previous systematic reviews have demonstrated the benefits of long-term macrolide use. However, the therapeutic differences between different macrolides and the optimal duration of use remain unclear. Methods: A systematic review and meta-analysis were conducted to assess the effectiveness of long-term macrolide use in reducing COPD exacerbations, compare the therapeutic differences among macrolides, and determine the appropriate treatment duration. Four databases (PubMed, Cochrane Library, Web of Science, and ICHU-SHI) were searched until 20 March 2023, and a random-effects model was used to calculate the pooled effect. Results: The meta-analysis included nine randomized controlled trials involving 1965 patients. The analysis revealed an odds ratio (OR) of 0.34 (95% confidence interval [CI] 0.19, 0.59, p < 0.001) for the reduction in exacerbation frequency. Notably, only azithromycin or erythromycin showed suppression of COPD exacerbations. The ORs for reducing exacerbation frequency per year and preventing hospitalizations were -0.50 (95% CI: -0.81, -0.19; p = 0.001) and 0.60 (95% CI: 0.3, 0.97; p = 0.04), respectively. Statistical analyses showed no significant differences between three- and six-month macrolide prescriptions. However, studies involving a twelve-month prescription showed an OR of 0.27 (95% CI: 0.11, 0.68; p = 0.005; I2 = 81%). Although a significant improvement in St George's Respiratory Questionnaire (SGRQ) total scores was observed with a mean difference of -4.42 (95% CI: -9.0, 0.16; p = 0.06; I2 = 94%), the minimal clinically important difference was not reached. While no adverse effects were observed between the two groups, several studies have reported an increase in bacterial resistance. Conclusions: Long-term use of azithromycin or erythromycin suppresses COPD exacerbations, and previous studies have supported the advantages of a 12-month macrolide prescription over a placebo.

Striatal dopamine transporter binding differs between dementia with Lewy bodies and Parkinson's disease with dementia.

123I-ioflupane single-photon emission computed tomography (SPECT) is a highly sensitive and established neuroimaging technique for parkinsonian syndromes (PS). However, differentiating PS by visual inspection or analysis of regions of interest is challenging. To date, image analysis has not been able to differentiate dementia with Lewy bodies (DLB) from Parkinson's disease with dementia (PDD). This study aimed to differentiate PS based on the characteristics of striatal dopamine transporter (DAT) binding using voxel-based analysis. We acquired 123I-ioflupane SPECT data from patients with DLB (n = 30), Parkinson's disease (PD; n = 122), PDD (n = 19), multiple system atrophy with predominant parkinsonism (MSA-P; n = 18), and progressive supranuclear palsy (PSP; n = 45). DAT binding was reduced in the posterior striatum of patients with PD and PDD, whereas it was similar in MSA-P, PSP, and DLB. Hippocampal atrophy, visually evaluated by cerebral magnetic resonance imaging, did not affect striatal DAT binding in DLB. DAT binding in the anterior striatum was inversely correlated with the severity of parkinsonism in PD and PDD but not in DLB. Thus, the appearance of striatal DAT binding might indicate different pathological processes in DLB and PDD.

Experimental investigation of the effective point of measurement for plane-parallel chambers used in electron beam dosimetry.

In this study, the effective point of measurement (EPOM) for plane-parallel ionization chambers in clinical high-energy electron beams was determined experimentally. Previous studies have reported that the EPOM of plane-parallel chambers is shifted several tens of millimeters downstream from the inner surface of the entrance window to the cavity. These findings were based on the Monte Carlo (MC) simulation, and few experimental studies have been performed. Thus, additional experimental validations of the reported EPOMs were required. In this study, we investigated the EPOMs of three plane-parallel chambers (NACP-02, Roos and Advanced Markus) for clinical electron beams. The EPOMs were determined by comparing the measured percentage depth-dose (PDD) of the plane-parallel chambers and the PDD obtained using the microDiamond detector. The optimal shift to the EPOM was energy-dependent. The determined EPOM showed no chamber-to-chamber variation, thereby allowing the use of a single value. The mean optimal shifts were 0.104 ± 0.011, 0.040 ± 0.012, and 0.012 ± 0.009 cm for NACP-02, Roos, and Advanced Markus, respectively. These values are valid in the R50 range from 2.40 to 8.82 cm, which correspond to 6-22 MeV. Roos and Advanced Markus exhibited similar results to those of the previous studies, but NACP-02 showed a larger shift. This is probably due to the uncertainty of the entrance window of NACP-02. Therefore, it is necessary to carefully consider where the optimal EPOM is located when using this chamber.

Delivery accuracy of VMAT on two beam-matched linacs provided by accelerated go live service.

INTRODUCTION: Dosimetric accuracy is critical when a patient treated with volumetric modulated arc therapy (VMAT) is transferred to another beam-matched linac. To evaluate the performance of Accelerated Go Live (AGL) service, the measured beam characteristics and patient specific quality assurance (QA) results between two AGL-matched linacs were compared. MATERIALS AND METHODS: Two VersaHD linacs were installed using the AGL service. After the installation, the beam data such as percentage depth dose (PDD), lateral profiles and output factors for all photon beams were measured. Relative doses were also measured as a function of the multi-leaf collimator (MLC) leaf gap width. Subsequently, VMAT plans were created for prostate, pelvis, head and neck, liver, lung cancers and multiple brain metastases. Dose distributions and point doses were measured by multi-dimensional detectors and ionization chambers for patient specific quality assurance, and comparisons were made between the two linacs. RESULTS: Dose differences in PDDs were all within ± 1% except the entrance region, and the averaged gamma indices of the lateral profiles were within 0.3. The differences in doses as a function of the MLC leaf gap width between the two linacs were within ±0.5%. For all the plans, gamma passing rates were all higher than 95% with criteria of 2%/2 mm. The average and the SD of dose differences on the multi-dimensional detector between both measurements was 0.06 ± 2.12%, and the average of point dose differences was -0.03 ± 0.33%. CONCLUSION: We have evaluated the AGL performance in the context of beam characteristics and patient specific QA. It was demonstrated that the AGL service provides an accurate VMAT treatment reproducibility for many tumor sites with gamma pass rates greater than 95% under criteria of 2%/2 mm.

A new workflow of the on-line 1.5-T MR-guided adaptive radiation therapy.

PURPOSE: The aim of this study was to develop a new workflow for 1.5-T magnetic resonance (MR)-guided on-line adaptive radiation therapy (MRgART) and assess its feasibility in achieving dose constraints. MATERIALS AND METHODS: We retrospectively evaluated the clinical data of patients who underwent on-line adaptive radiation therapy using a 1.5-T MR linear accelerator (MR-Linac). The workflow in MRgART was established by reviewing the disease site, number of fractions, and re-planning procedures. Five cases of prostate cancer were selected to evaluate the feasibility of the new workflow with respect to achieving dose constraints. RESULTS: Between December 2021 and September 2022, 50 consecutive patients underwent MRgART using a 1.5-T MR-Linac. Of these, 20 had prostate cancer, 10 had hepatocellular carcinoma, 6 had pancreatic cancer, 5 had lymph node oligo-metastasis, 3 had renal cancer, 3 had bone metastasis, 2 had liver metastasis from colon cancer, and 1 had a mediastinal tumor. Among a total of 247 fractions, 235 (95%) were adapt-to-shape (ATS)-based re-planning. The median ATS re-planning time in all 50 cases was 17 min. In the feasibility study, all dose constraint sets were met in all 5 patients by ATS re-planning. Conversely, a total of 14 dose constraints in 5 patients could not be achieved by virtual plan without using adaptive re-planning. These dose constraints included the minimum dose received by the highest irradiated volume of 1 cc in the planning target volume and the maximum dose of the rectal/bladder wall. CONCLUSION: A new workflow of 1.5-T MRgART was established and found to be feasible. Our evaluation of the dose constraint achievement demonstrated the effectiveness of the workflow.

Serum Free Radical Scavenging Capacity Profiles of Patients with Chronic Obstructive Pulmonary Disease.

Background: Oxidative stress is an important mechanism for the development and progression of chronic obstructive pulmonary disease (COPD). It may also contribute to systemic manifestation in patients with COPD. Reactive oxygen species (ROS) including free radicals play a crucial role in oxidative stress in COPD. The aims of this study were to determine serum scavenging capacity profile against multiple free radicals and to evaluate its correlation with pathophysiology, exacerbations, and prognosis in patients with COPD. Methods: Serum scavenging capacity profile against multiple free radicals comprising hydroxyl radical (•OH), superoxide radical (O2 -•), alkoxy radical (RO•), methyl radical (•CH3), alkylperoxyl radical (ROO•), and singlet oxygen (1O2) was assessed using the multiple free-radical scavenging method in 37 patients with COPD (mean age, 71 years; mean forced expiratory volume in 1 s, 55.2% predicted). The severity of emphysema was evaluated by Goddard classification on chest computed tomography. Exacerbations were recorded prospectively for 1 year and the overall mortality was assessed 5 years after the initial assessment. Results: •OH scavenging capacity was significantly decreased (p < 0.05) and O2 -• and •CH3 scavenging capacity tended to decrease in patients with COPD compared to that in healthy controls. On the other hand, ROO• scavenging capacity tended to increase. In addition, RO• scavenging capacity was associated with severity of emphysema (p < 0.05) and exacerbation frequency (p < 0.02). There was a difference in the profile of the scavenging capacity between survived and deceased patients with COPD for 5 years after initial assessment. Conclusion: Characteristic profile of free radical scavenging capacity can provide insight into the pathophysiology and prognosis of patients with COPD.

Coupling of Cortical Hyperintense Signals and Increased Glucose Metabolism in a Case of Anti-GABAA Receptor Antibody-associated Encephalitis.

We herein report a case of anti-gamma aminobutyric acid type A receptor antibody-associated encephalitis (anti-GABAA-RE) with progressive aphasia and generalized tonic-clonic seizures. Cerebral magnetic resonance imaging (MRI) showed cortical brain lesions coupled with hypermetabolism on fluorodeoxyglucose-positron emission tomography. After two courses of methylprednisolone pulse therapy, improvements in neurological symptoms without sequelae and the total disappearance of MRI lesions were observed. Upon encountering patients with refractory status epilepticus, multifocal cerebral MRI lesions, and suspected autoimmune encephalitis, especially in cases with thymoma, it would be prudent to suspect anti-GABAA-RE and consider the evaluation of anti-GABAA receptor antibody and methylprednisolone pulse therapy.

Clinical, radiological, and molecular analyses of neuronal intranuclear inclusion disease with polyglycine inclusions.

Neuronal intranuclear inclusion disease (NIID) is a clinically complex neurological disorder that appears sporadically or autosomally. Expansions of intronic GGC trinucleotide repeats in the NOTCH2 N-terminal-like C (NOTCH2NLC) gene cause NIID. In this study, to clarify the clinical characteristics useful for the differential diagnosis of NIID, clinical data of neurological examination, neuroimaging, and nerve conduction studies of six NIID patients diagnosed by pathological or genetic investigations were analyzed. Clinically useful characteristics for diagnosing NIID include general hyporeflexia, episodic disturbance of consciousness, sensory disturbance, miosis, and dementia. Furthermore, neuroimaging findings, such as leukoencephalopathy in T2-weighted magnetic resonance imaging and a linear high intensity of subcortical U-fibers in diffusion-weighted imaging (DWI), as well as decreased motor nerve conduction velocity, are especially important biomarkers for NIID. However, it is necessary to remember that these features may not always be present, as shown in one of the cases who did not have a DWI abnormality in this study. This study also investigated whether expanded GGC repeats were translated into polyglycine. Immunohistochemical analysis using a custom antibody raised against putative C-terminal polypeptides followed by polyglycine of uN2CpolyG revealed that polyglycines were localized in the intranuclear inclusions in skin biopsy specimens from all six patients, suggesting its involvement in the pathogenesis of NIID.

The efficacy and safety of additional treatment with short-acting muscarinic antagonist combined with long-acting beta-2 agonist in stable patients with chronic obstructive pulmonary disease: A systematic review and meta-analysis.

BACKGROUND: The rationale for additional treatment with short-acting bronchodilators combined with long-acting bronchodilators for patients with chronic obstructive pulmonary disease (COPD) is not adequately studied. METHODS: We conducted a systematic review and meta-analysis to evaluate the efficacy and safety of a short-acting muscarinic antagonist (SAMA) therapy combined with a long-acting beta-2 agonist (LABA) in patients with stable COPD. Pulmonary function, dyspnea, health-related quality of life, exercise tolerance, physical activity, exacerbations of COPD, and adverse events during regular use were set as outcomes of interest. RESULTS: We included five controlled trials including two sets of publicly available online data without article publications for the meta-analysis. Additional use of SAMA plus LABA showed a significant improvement in the peak response in FEV1 (mean difference (MD) 98.70 mL, p < .00001), transitional dyspnea index score (MD .85, p = .02), and St George's Respiratory Questionnaire score (MD -2.00, p = .008) compared to LABA treatment. There was no significant difference in the risk of exacerbation of COPD (p = .20) and only a slight trend of increased severe adverse events (OR: 2.16, p = .08) and cardiovascular events (OR: 2.38, p = .06). CONCLUSION: Additional treatment with SAMA combined with LABA could be a feasible choice due to its efficacy and safety.

Mini Nutritional Assessment Short-Form as screening tool for osteoporosis in patients with chronic obstructive pulmonary disease.

BACKGROUND AND OBJECTIVES: Osteoporosis is a common complication of chronic obstructive pulmonary dis-ease (COPD). It is impractical to measure bone mineral density (BMD) in all patients with COPD. This study aimed to investigate the relationship between Mini Nutritional Assessment Short-Form (MNA-SF), a simple nutritional status questionnaire, and osteoporosis, and to determine whether it can be used as a reliable screening tool for osteoporosis in patients with COPD. METHODS AND STUDY DESIGN: Thirty-seven patients with stable COPD were enrolled in this prospective cohort study. Patients with MNA-SF scores >11 were defined as well-nourished, and those with scores of ≤11 being at risk for malnutrition. Body composition, BMD, and undercarboxylated osteocalcin (ucOC), a bone metabolism marker, were measured using bioelectrical impedance, dual energy X-ray, and electrochemiluminescence immunoassay, respectively. RESULTS: Seventeen (45.9%) were classified as at risk for malnutrition, and 13 (35.1%) had osteoporosis. Patients at risk for malnutrition had significantly more osteoporosis and higher ucOC values than well-nourished patients (p=0.007, p=0.030, respectively). Patients with osteoporosis also had significantly lower body mass index (BMI) and fat-free mass index than those without osteoporosis (p= 0.007 and p=0.005, respectively), although FEV1 % pred was not significantly different. MNA-SF (cutoff value; 11) had better sensitivity to identify the presence of osteoporosis than BMI (cutoff value; 18.5 kg/m2) (sensitivity, 0.769; specificity, 0.708; sensitivity, 0.462; specificity, 0.875, respectively). CONCLUSIONS: MNA-SF was associated with osteoporosis and bone metabolism markers in patients with COPD. MNA-SF may be a useful screening tool for osteoporo-sis in patients with COPD.

DEVELOPMENT OF ABSOLUTE MEASUREMENT SYSTEM FOR 𝑾AIR IN 60CO GAMMA RAYS.

In the ICRU Report 90, the uncertainty of the recommendation for ${{W}}_{{air}}$ was changed from 0.15 to 0.35%. The purpose of this study is to develop an absolute measurement system for ${{W}}_{{air}}$ in electrons with lower uncertainty using 60Co gamma rays. ${{W}}_{{air}}$ was determined by the ratio of the energy deposition to the number of ion pairs created in a given volume of air using a graphite calorimeter and a graphite-wall ionisation chamber. The obtained value for ${{W}}_{{air}}$ was 33.91 eV with a relative standard uncertainty of 0.08 eV (k = 1), and was in good agreement with the recommended value of the ICRU Report 90 (33.97 eV). Additionally, the uncertainty for ${{W}}_{{air}}$ obtained in this investigation is 0.23% and is comparable with that reported by Burns et al., which is the lowest uncertainty in recent studies determining ${{W}}_{{air}}$ In the future, the proposed system can be used to measure ${{W}}_{{air}}$ in high-energy electron beams.

Transition of Antibody Titers after SARS-CoV-2 mRNA Vaccination in Japanese Healthcare Workers.

Since February 2021, healthcare workers in Japan have been preferentially vaccinated with a messenger RNA vaccine (BNT162b2; Pfizer/BioNTech) against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). While many studies have confirmed that this vaccine is highly effective in reducing hospitalization and deaths from coronavirus disease 2019 (COVID-19), antibody titers tend to decline at 3 months after vaccination, leading to a risk of breakthrough infections. Thus, information is needed to support the decision regarding the 3rd vaccination. In this study, we investigated the transition of anti-SARS-CoV-2 spike protein receptor-binding domain (RBD) IgG and neutralizing antibody titers in 37 vaccinated Japanese healthcare workers. Samples were collected 6 times starting before vaccination until 6 months after the second vaccination. The levels of anti-SARS-CoV-2 RBD IgG peaked 1 week after the 2nd vaccination, then declined over time and decreased to < 10% at 6 months after the 2nd vaccination. Additionally, approximately one-third of the healthcare workers were seronegative for the Omicron variant 6 months after the 2nd vaccination. Workers with low anti-SARS-CoV-2 RBD IgG levels also had low neutralizing antibody titers. These data support booster dose administration for healthcare workers, especially those with low anti-SARS-CoV-2 RBD IgG levels.

[A Survey of Dosimetry in the Magnetic Field of MR-Linacs].

In recent years, MR-Linac, a radiotherapy linear accelerator (linac) equipped with magnetic resonance (MR) imaging, has been deployed in clinical facilities across Japan. Because of the magnetic field of MR-Linac, which can affect the dose distributions and dose response of ionization chambers, conventional reference dosimetry for absorbed dose to water using an ionization chamber becomes impractical. Consequently, the magnetic field effect should be considered in the reference dosimetry for MR-Linac. Although numerous studies have delved into this matter and several magnetic field correction methods have been proposed to extend the conventional formalism, a practical protocol for reference dosimetry for MR-Linac remains elusive.The purpose of this review are as follows: (i) to summarize and evaluate literature and existing datasets as well as identify any gaps that highlight areas for the future research on this topic; (ii) to elucidate dosimetric challenges associated with ionization chamber dosimetry in magnetic fields; and (iii) to propose a formalism for reference dosimetry for MR-Linac based on available literature and datasets. This review focuses on studies based on commercially available MR-Linacs and datasets, specifically tailored for reference-class cylindrical ion chambers.

Successful management of recurrent allergic bronchopulmonary aspergillosis after changing from mepolizumab to dupilumab: A case report.

An 81-year-old woman presented to our hospital due to an abnormal shadow on a chest X-ray and a 4-week-old persistent cough. Laboratory examination revealed increased serum eosinophils and immunoglobulin E. The Asthma Control Test (ACT) score and forced expiratory volume in 1 sec indicated airway obstruction. Chest computed tomography (CT) revealed mucoid impaction in the dilated left-lingular lobar bronchus. She was diagnosed with bronchial asthma and treated with a high-dose inhaled corticosteroid/long-acting ß2 agonist. Two months later, her mucoid impaction in the CT image worsened; moreover, bronchoscopy revealed the white mucus plug with Charcot-Leyden crystals and filamentous fungi. The patient was diagnosed with Allergic bronchopulmonary aspergillosis (ABPA) and treatment with 30 mg/day prednisolone was started. Both the blood eosinophil count and the chest image improved almost substantially, and the steroid was discontinued after a year. Sixteen months after cessation of prednisolone treatment, peripheral eosinophilia and mucoid impaction in the left B3b recurred. For the treatment of bronchial asthma and recurrent ABPA, administration of mepolizumab was initiated. Subsequently, although her peripheral eosinophils count decreased, chest CT showed expansion of the mucoid impaction and IgE increased despite mepolizumab treatment. Alternative subcutaneous injection therapy with dupilumab improved chest image, serum IgE level, and her ACT score. After changing from mepolizumab to dupilumab, her ABPA, asthma, and pulmonary function improved remarkably. This case illustrates the potential utility of dupilumab for ABPA without re-administration of oral prednisolone. Additional research is needed to identify an effective therapy for ABPA with asthma.

Improvement of peripheral neuropathy in a patient with antineutrophil cytoplasmic antibody-negative eosinophilic granulomatosis with polyangiitis by additional mepolizumab.

BACKGROUND: Eosinophilic granulomatosis with polyangiitis (EGPA) is a vasculitis characterized by abnormally high eosinophils and frequent peripheral neuropathy. Mepolizumab is an approved therapy for EGPA, but its efficacy against peripheral neuropathy remains unknown. CASE PRESENTATION: A 41-year-old woman was admitted in the hospital with dyspnea and neuropathy. Ground glass opacity and infiltrative shadow in the bilateral lungs were evident on chest computed tomography images. Eosinophils were increased in serum, in bronchoalveolar lavage fluid (BALF), and in transbronchial lung biopsy, and bacteria were not detected in BALF. EGPA resulting in severe eosinophilic asthma, sinusitis, pulmonary infiltrates, and peripheral neuropathy was diagnosed. Prednisolone (50 mg/day) caused remission of eosinophilic pneumonia and sinusitis, but not peripheral neuropathy. During prednisolone tapering (7 mg/day, 10 months after treatment), eosinophils were increased, and peripheral neuropathy relapsed. The humanized anti-IL-5 antibody mepolizumab (300 mg) was initially administered, followed by prednisolone. Mepolizumab caused sustained peripheral neuropathy remission and effective prednisolone tapering. CONCLUSIONS: Introduction of mepolizumab combined with prednisolone may improve peripheral neuropathy.